®I|e 39, 31. ^ill ICibranj 5?orth Carolina Slate CoUi-ne 56755 T6 till Hill Hill iliiliilliiiillililJI S00825952 V n 17075 This BOOK may be kept out TWO WEEKS ONLY, and is subject to a fine of f¥Pfr CENTS a day thereafter. It is due on the day indicated below: MAR31196J 0C1 0^, 6 19I& H DISEASES OF PLANTS Induced by Cryptogamic Parasites hitrodiiction to the Study of Pathogenic Fungi, Slime-Fu?igi, Bacte7'ia, & Algae BY Dr. KARL FREIHERR von TUBEUF I'KIVATDOZENT IN THE UMVEKSITV OF MUNICH English €i)iti0u bj) WILLIAM G. SMITH, B.Sc, Ph.D. LECTURER ON PLANT PHYSIOLOGY UNIVERSITY OF EDINBURGH THREE HUNDRED AND THIRTY ILLUSTRATIONS LONGMANS, GREEN & CO. LONDON, NEW YORK, AND BOMBAY 1897 Ail rights resenied GLASGOW : ^tintfb at Ihc anibrrsitti JJrcse bg ROBEKT MACLEHOSE AND CO. AUTHOR'S PREFACE. In my research work, and in connection with my lectures at the University and Technical School of Munich, I have for some time felt convinced that there existed a very evident gap in the literature relating to the diseases of plants. There was need of a newer and more complete work on cryptogamic para- sites and the diseases induced by them on higher plants, a work furnished with many accurate illustrations, with a survey of the newer literature, and with a general part wherein parasitism and the relations between parasite and host are discussed from a botanical standpoint. Therefore, I have undertaken to write a book intended to supply in some degree this pressing want. Here the attempt has been made for the first time to review in a general and comparative manner the biological, physiological, and anatomical relationships accompanying the phenomena of parasitism. Already De Bary has considered the varying degrees of parasitism and the phenomena of symbiosis in his celebrated Morphology and Biology of the Fungi ; while Wakker has laid the foundations of our knowledge of the alterations in the anatomy of plants diseased by the agency of fungi, more especially, however, those alterations accompanying 'hypertrophy.' I venture to continue this difficult and comprehensive chapter of plant physiology, because for ten years I have devoted my time to the study of plant pathology. The book may be all the more acceptable since I have confirmed a large number of the observations and added the results of my own investigations, many of them now published for the first time. The present time is favourable to my work. The great Sylloge Fungorum of Saccardo (with its appendices in Vols. ix. and X.) has been recently completed ; the classic investigations ^^^. ^^ X^ vi AUTHOR'S PREFACE. of Brefeld iu the domain of mycology, and containing his classification of the fungi, are now well advanced ; the Kryi^to- gamcn-Flora of Rabenhorst is nearly completed ; and the newer literature and observations are now periodically reviewed in the Zeitficlirift fur Pflanzcnlcrankheiten, and other magazines. The recent publication of several investigations on the intiuence of parasites on the anatomy of their host-plants greatly facilitated the compilation of the general part of the work. I have here attempted to summarize in a systematic manner the preventive and combative agencies available against the more important diseases of economic plants. In many cases these are supported by facts given in the chapters on the natural and artificial infection of host-plants, and their disposition towards diseases produced by lower organisms. As already indicated in the title-page, the book deals only with those diseases of plants produced by the cryptogams and other lower organisms of the vegetable kingdom. The large number of parasites which attack such lower plants as algae and lichens, although not altogether neglected, have as a rule been omitted, otherwise the book could not have been brought within the limits of a single volume. In the second or systematic part of the book, the pathological phenomena are considered along with the description of the organism producing them. Where the diseases are of economic importance, measures for pre- vention and extermination are also suggested. Notices of greater length are given to such parasites and diseases as have formed the subject of special investigations. We could only aim at a complete list for Germany and the neighbouring countries, yet we have included many species of interest occurring in other parts of the world, notably in America. Though it will be possible to identify most of the more important parasites by the aid of this book, we do not intend it to replace the systematic works ; we purpose rather to add to the descriptions given in Eabenhorst, Saccardo, and similar works. This book is intended above all to be, in the terms of its title-page, " an Introduction " ; hence it seeks to orient in a general way, to give a summary of our knowledge, and to indicate the way to more detailed records. On this account great care has been taken in the citation of home and foreign literature, not only up to the time of finishing the manuscript AUTHOR'S PREFACE. VU (Easter, 1894), but also during the time of proof-reading up till the following Christmas. Eeference to the book will be rendered easier by the numerous illustrations, which are almost exclusively the work of the author, and reproduced either from drawings or from photographs of the living objects, in many cases taken in situ. I consider it more essential to illustrate the habitus of pathological objects rather than to give drawings of microscopic subjects ; those one may find in other works. Some of the illustrations are copied from the excellent plates of Tulasne, Woronin, De Bary, Klebs, Eeess, Cohn, and Eobert Hartig ; while a number of woodcuts have been borrowed from the well-known Lehrhuch dcr Bmimkrank- heiten of the last named author. The grouping of the ' Fungi imperfecti,' which have not yet been worked up for the German flora, is based on Saccardo's Sylloge ; hence the arrangement into Hyalosporae, etc., which is intended for the benefit of those having access to Saccardo. Particular attention has been paid in the two Tndices to the scientific names of both parasites and hosts, to popular names, and to technical expressions. In my labours I received great assistance from the following sources : From the collection of pathological material begun by Professor Robert Hartig, and now carried on with my help in the Botanical Institute of the Eoyal Bavarian School of Forestry in Munich ; from the facilities for research and photography afforded by the laboratories of the same institution ; from the Eoyal Library of Munich, the Library of the University, and the private pathological library of Professor Hartig. Living material for investigation Itas been kindly sent to me from many sources, particularly from the following gentlemen : Herr Lehrer Schnabl of Munich, Geh. Oberregierungsrath Prof. Kiihn of Halle, Hofgiirtner Kaiser of Munich, Prof. Dr. Fries of Upsala, Forstrath von Plonnies and Oberforster Losch at Amorbach. Preserved material came from Herr Hauptlehrer Allescher of Munich, Director Dr. Goethe and Dr. Wortmann in Geisenheim, Prof. Dr. Stahl of Jena, Prof. Dr. Magnus of Berlin, Prof. Dr. Grasmann and Prof. Dr. Loew of Tokio. Dr. Bruns of Erlangen kindly photographed some specimens in the botanical museum there. Numerous botanists have greatly assisted me by sending papers, especially Dr. Dietel of Leipzig ; I have also to VIU AUTHORS PREFACE. thank him for valuable aid with the Uredineae. To Prof. Dr. Soxhlet I am indebted for literature and the opportunity given to establish a museum of pathological material in connection with the agricultural division of the Munich Technical School. Dr. Solla of Trieste, while working in our laboratory here, very kindly translated the earlier fascicles of the ' Funghi parasitic! ' of Briosi and Cavara as far as they were then published. Prof. Dr. Wollny allowed me to carry out some researches on his experimental fields. Very opportune were the investigations of my pupils, Dr. Woernle and Dr. W. G. Smith, on the anatomical changes in plants attacked by Gymnosporangeae and Exoasceae respectively. To all these gentlemen, and to many more who sent me material, but whom it is impossible to name individually in this place, I here express my warmest thanks. The reproduction of my drawings and photographs has been most carefully carried out by Herr 0. Cons^e of Munich. I am also deeply indebted to the publisher, Herr Springer, for the excellent manner in which he has done his work ; this will no doubt be also appreciated by the reader. V. TUBEUF. Munich, December, 18.94. NOTE TO THE ENGLISH EDITION. Since the publication of this work, I have received a large contribution of original papers. Though there was no time to embody all these in the English edition, yet many of them have been used for its correction and amplification. Some were of such a kind as to necessitate the re-writing of whole sections, notably those on the genera Exoascus and Gymnosporangium. The remainder will be thoroughly revised if a second German edition be called for. I again take the opportunity of thanking all those who have sent me literature, and I shall be grateful if they will continue to do so in the future. v. TUBEUF. Munich, December, 1895. PREFACE TO THE ENGLISH EDITION. My justification for placing another translation in our libraries is that no such book as this exists in the English language, and that I could not, for some considerable time, see my way to collect so many observations on the cryptogamic parasites of higher plants, or to find so many suitable subjects for the pictorial illustration of their habits and structure, as Dr. von Tubeuf has given us. The work was undertaken all the more willingly, because, while working under the guidance of the author, I had seen the book take shape in his hands, and even added some items to its pages. The aims of the book are sufficiently set forth in the author's preface, and in the preparation of an English edition these have been kept in view. The first or general part and the more important descriptions in the second part are practically translations, but a certain amount of modification was found necessary in adapting the work to the requirements of English readers. With this object many additions were made both by the author and myself. Those which I have inserted are in most cases indicated by the use of (Edit.); this has, how- ever, been entirely omitted in the group ' Fungi imperfecti,' and nearly so in the Uredineae, on account of the number of changes found necessary. I also thought it advisable to indicate whether the different species of fungi had been recorded for Britain and North America; this has been done generally by the use of brackets, — (Britain and U.S. America.) The records for Britain are taken from the works of Plowright, Massee, and others ; those of three groups, — the Uredineae, Basidiomycetes, and ' Fungi imperfecti ' were, however, revised by Professor J. W. H. Trail of Aberdeen, a well-known aiithoritv- For America X PREFACE TO THE ENGLISH EDITION. the records of economic interest are selected chiefly from Farlovv and Seymour's Host-Indc.v, which contains the complete list. I here take the opportunity of expressing my thanks to Professor I. Bayley Balfour for valuable aid and advice; to Professor J. W. H. Trail for kindly revising important parts of the proofs; to my brother, Pobert Smith, for assistance in proof- reading, and to other friends who have aided me. The difficulties of translation are well known ; in the present case they have been increased by the technical nature of the subject, and by the modification which the original has under- gone. Faults there must be; for those I ask the indulgence of the reader. W. G. SMITH. Royal Botanic Garden, Edinburgh, October, 1896. BIBLIOGRAPHY. The following are some of the more important general works and text books. Books and papers on special subjects are given throughout the text as foot-notes : — General Works on Fungi. TuLASNE. Selecta fungorum carpologia. 1861-1865. De Bary. Comparative Morphology and Biology of the Fungi, Mycetozoa, and Bacteria. English edition. 1887. ZoPF. "DiePilze." Schenk's Handbuch der Botariik. 1890. LuDwiG. Lehrbuch der niederer Kryptogamen. 1892. Brefeld. Untersuchungen aus dem Gesammtgebiete der Mycologie. 1872-1891. Tavel. Vergleichende Morphologie der Pilze. 1892. Saccardo. Sylloge fungorum. 1882-1893. Winter, Fischer, and Kehm. " Die Pilze." Eabenhorst's Kryptogamen- flora. ScHROETER. " Die Pilze." Cohn's Kryptogamenflora von Schlesien. 1885- 1894. (Incomplete.) ScHROETER. " Die Schleimpilze und die Pilze." Engler-Prantl natUrlichen Pflauzenfamilien. 1892-1894. (Not yet complete.) CooKE. Handbook of British Fungi. 1871. Plowright. British Ustilagineae and Uredineae. 1889. Farlow and Seymour. Host-Index of the Fungi of the United States. 1888-1891. Massee. British Fungus-Flora. 1892-1895. Works on Diseases of Plants. Unger. Die Exantheme der Pflanzen und einige mit diesen verwandte Krankheiten der Gewachse. 18.33. WiEGMANN. Die Krankheiten und krankhaften Misbildungen der Gewachse. 1839. Meyen. Pflanzenpathologie. 1841. Xll BIBLIOGRAPHY. De Bary. Untersuchungen iiber die Brand ])ilze and die durch sie verur- sachten Krankheiteii der Pflanzen. 1853. KtJHN. Die Krankheiteii der Kulturgewiichse und ihre Verbiitung. 1858. Hallier. Phytopathologie ; die Krankheiten der Kultiirgewacbse. 1868. Hartig, R. Wichtige Krankbeiten der Waldbaiune. 1874. Hartig, R. Die Zersetzungser.scbeinungen des Holzes. 1878. Frank. Die Krankbeiten der Pflanzen. I. Aufl. 1880, II. Aufl. 1894-1896. Hartig, R. Lebrbucb der Baumkranklieiten. I. Aufl. 1882, II. Aufl. 1889. (Editions in Englisb, French, and Russian.) Smith, Worth. G. Diseases of Field and Garden C^rops. 1884. SoRAUER. Handbuch der Pflanzenkrankheiten. II. Aufl. 1886. Wolf and Zopf. Krankbeiten der landwirtbscbaftlicben Nutzpflanzen durcb Scbmarotzerpflanzen. 1887. SoRAUER. Die Scbaden der einheimiscben Kulturpflanzen durcb tbieriscbe und pflanzHche Schmarotzer. 1888. Marshall Ward. Timber and some of its Diseases. 1889. KiRCiiNER. Die Krankbeiten und Bescbadigungen unserer bmdwirtbscbaft- licben Kulturpflanzen. 1890. Frank and Sorauer. Pflanzenscbutz. 1892. Prillieux. Maladies des plantes agricoles et des arbres fruitiers et forestiers causees par des parasites vegetaux. 1895. Zeitscbrift fur Pflanzenkrankheiten (since 1891). The Publications of the Division of Vegetable Pathology of the Department of Agriculture, U.S. America, issued from Washington. The Bulletins of the Agricultural Experimental Stations, issued by many of the States and Universities of the United States. Exsiccata of Parasitic Fungi, by (a) Briosi and Cavara, (h) Eriksson. " Economic Fungi " of U.S. America, by Seymour and Earle ; Exsiccata begun 1890, (still being issued). Etc., etc. CONTENTS. PART FIRST. CHAPTER I. THE PARASITIC FUNGI. PAGE § 1. Definition of the Parasitism of Fungi, ... 2 § 2. Classification of Parasites and Saprophytes, - - . 3 § 3. Mode of Life of the Parasitic Fungi, ... 7 CHAPTER 11. REACTION OF HOST TO PARASITIC ATTACK. § 4. Effect of Parasitic Fungi on their Host, - - .14 § 5. Effect of Parasitic Fungi on the Form of the Host-Plant, 22 § 6. Effect of Parasitic Fungi on Cell-Contents, - - 31 § 7. Effect of Parasitic Fungi on the Cell-Wall, - - 36 § 8. Effect of Parasitic Fungi on the Tissues of their Host, 40 CHAPTER in. RELATION OF PARASITE TO SUBSTRATUM. 9. Effect of the Substratum on the Development of the Parasite, ------- 45 XIV CONTENTS. CHAPTER IV. PAGE § 10. NATUEAL AND ARTIFICIAL INFECTION, - - 50 CHAPTER V. §11. DISPOSITION OF PLANTS TO DISEASE, - - 68 CHAPTER VL § 12. PREVENTIVE AND COMBATIVE MEASURES, - - 63 I. Extermination and Removal of the Parasitic Fungi alone, - - - - - 65 II. Removal and Destruction of Diseased Plants, - 71 III. Avoidance or Removal of Conditions which Favour Infection, ------ 75 IV. Selection of Hardy Varieties, - - - 81 CHAPTER Vn. § 13. ECONOMIC IMPORTANCE OF DISEASES OF PLANTS, 83 CHAPTER Vni. SYMBIOSIS: MUTUALISM, 86 CHAPTER IX. SYMBIOSIS: NUTRICTSM, 92 Ectotrophic Mycorhiza, - - - - - 93 Endotrophic Mycorhiza, - - - - - 97 Mycodomatia of the Alder, etc., - - - - 99 Mycodomatia of the Leouminosae, - - - - 101 CONTENTS. PART SECOND. SYSTEMATIC ARRANGEMENT OF THE CRYPTOGAMIC PARASITES. PAOB I. THE PATHOGENIC FUNGI OF PLANTS, - - - 104 A. Lower Fungi (Phycomycetes), - - - - 106 (1) Chytridiaceae, ..... 106 (2) Zygomycetes, - - - . - - 114 (3) OoMYCETES : Peronosporeae, . . - - 115 B. Higher Fungi (Mycomycetes), - - - - 135 ASCOMYCETES, - - - . . - 13& A. Gymnoasci, . . . - - 137 The Parasitic Exoasceae, - . - 144 B. Carpoasci, ...... 168 Perisporiaceae, . - - - 170 Pyrenomycetes, .... 183 Hysteriaceae, - ... - 232 Discomycetes, ----- 240 Ustilagineae, --..-- 275 Uredineae, - ...... 328 Basidiomycetes, -.---. 421 Fungi Imperfecti — I. Sphaeropsideae, - - - 463 II. Melanconieae, - - - 482 III. Hyphomycetes, - . - 496 II. THE PATHOGENIC SLIME-FUNGI, - . - 522 III. THE PATHOGENIC BACTERIA, - - . . 530. IV. THE PATHOGENIC ALGAE, - . - . 539 INDEX OF PARASITES, ----.. 556 GENERAL INDEX, . - 580 ERRATA. Page 9, Fig. 1, for " Erysipheae " read " Erysiphe." 35, line 11 from foot, for " tyrosin " read " trypsin." 181, ,, 24, for " quercinium " read " quercinum," 185, ,, 6, for " Nectrina " read " Nectria." 195, ,, 3, for " setuloso " read " setulosa." 256, ,, 6, /or " Belionella " rcrtd " Beloniella." 305, ,, 11 from foot, for Tolysporium" read "Toh-posporium." 312, ,, 16, /or " heloscladii " and " Heloscladium "' respectively, read " heloscladii " and " Helosciadium." 337, „ 10, for " Onybrychis " read " Onobrychis." 355, „ 25, for " Cichoria " read " Cichorium." 403, ,, 9, /o?' " Cypressus " reaci " Cupressus. " 404, ,, 5, /oj' "Escheveria" rcacZ " Echeveria." 420, ,, 3, for "Thecospora" read " Thecopsora." PART FIRST. CHAPTER I. THE PARASITIC FUNGI. The true Fungi, together with the Myxomyeetes or Slime-fungi, and the Schizomycetes or Bacteria, constitute a group of the Cryptogams characterized by lack of chlorophyll. In consequence, the members of the group are unable to utilize light as a source of energy, and nmst obtain their food as organized material, complex in comparison with the simple substances required by green plants. These fungi, in short, are, in common with animals, ultimately dependent for the greater portion of their support on living or dead chlorophyllous plants. According as they obtain nutriment from dead organic remains or from living plants or animals, we distinguish them as Saprophytes and Parasites respectively. The same mode of nutrition is found in the case of most non-chlorophyllous Phanerogams, and also in a few chlorophyllous plants, both Cryptogams and Phanero- gams. When parasitic Fungi, Bacteria, and other lower organisms attack higher plants, they, as a rule, endeavour to penetrate the living organs of their host. It is only when this penetration has taken place to some extent, and the parasite has thereby come into more or less close contact with the tissues of its host, that conditions suitable to a parasitic mode of nutrition are established. To deal with the lower forms of vegetable parasites, with their relations to their respective hosts, and with the structural altera- tions which they bring into existence in the latter, is our object in the present book. nortKn lu»ary 2 THE PARASITIC FUNGI. § 1. DEFINITION OF THE PARASITISM OF FUNGI. Parasitic Fungi are those which, stimulated by the cell- conlents of another living plant, penetrate wholly or partially into its tissues, and draw their nutriment from that source. Saprophytic Fungi are those which make no attempt to penetrate the tissues of living plants, but derive their nutriment from a dead substratum. Intermediate between these two extremes come those fungi which, in consequence of some stimulus, attempt to effect an entrance into the tissues of living plants by the secretion of some iiuid or ferment, but only attain their object after first killing the part they attack {e.g. Sderotinia sderotiorum). A special position must also be ascribed to certain forms which inhabit the wood of trees, but have not the power to penetrate through the outer tissues ; they depend on first gaining entrance through wounds into dead parts of the bark or wood, and, after living there for a time as saprophytes, extend into the living elements and cause their death. ]\Iany parasites may be artificially cultivated so as to pass some part of their life-history on dead pabulum, and even in natural conditions many of them regularly live for a season in a saprophytic manner. On this account it appears to me more correct, in distinguishing between parasites and saprophytes, to lay less weight on the adaptation to nutrition and more on their response to the stimuli exerted by living plant-cells. The nature of this stimulus which affects parasitic hyphae has not as yet been investigated. It appears probable, however, especially from the investigations of Pfeffer and Miyoshi,^ that the infiuence is primarily a chemical one, and that the nutritive value of the stimulating substance is not a measure of the ensuing effect. Biisgen states that the formation of adhesive-discs by germinating spores is induced by a stimulus due to contact, whereas the production and penetration of the first haustorium is independent of contact, and is probably due to some chemical stimulus (see p. 9). Miyoshi's investigations have also proved that saprophytic fungi are capable of penetrating into living plant-organs, even ' Miyoshi. " Ueber Chemotropismus d. Pilze." Botan. Zi'tfiDnj, 1S!)4 ; also " Die Durchbohruiig von Membranen duicli Pilzfaden." F)n)itj--i/ii i/n's Jahrhuch, 1895 Pfeffer. "Ueber Election organischer Nahrstoffe." Primjshfinis Jahrhuch, DEFINITION OF THE PARASITISM OF FUNGI. 6 of boring through cell-walls, if the part be impregnated with a stimulating solution. They behave here completely as parasites. For example, hyphae of Fenicillium glauciim penetrate into living cells of a leaf injected with a two per cent, solution of cane sugar, while without previous injection of the leaf they have never been observed to do so. . Fenicillium is also known, in certain circumstances, to become parasitic. Many species of fungi are capable of passing the whole or a part of their life as parasites on living plants. Conspicuous in this respect are the Uredineae and Ustilagineae, many Ascomy- cetes, including all Exoasceae and Erysipheae ; and amongst the lower fungi, most of the Chytridiaceae and all the Peronosporeae. Xor does this exhaust the list, for amongst the remaining fungi we may iind isolated families, genera, and even species occurring as parasites, while forms closely related to them are saprophytic. To classify the parasites, saprophytes, and intermediate forms, we shall adopt that arrangement proposed by Van Tieghem and De Bary. § 2. CLASSIFICATION OF PARASITES AND SAPROPHYTES. 1. True saprophytes are such as regularly pass through their whole life-history in a saprophytic manner. They may derive their nourishment from different kinds of pabulum, or be limited to some definite substratum. The true saprophytes do not come within the scope of this book.^ 2. Hemi-saprophytes (the 'facultative parasites' of De Bary) are wont to pass through their whole development as saprophytes, but on occasion are capable of existing wholly or partially as parasites. Amongst them are included particularly such species as may be designated " occasional parasites," which commonly occur as saprophytes, and only under certain conditions become parasitic. 3. True parasites (the 'obligate parasites' of De Bary). These undergo no part of their development as saprophytes, but live in every stage of existence as parasites. 4. Hemi-parasites (the 'facultative saprophytes' of De Bary) are capable, if need be, of becoming saprophytes for a season ^Johow proposes the term Holo-saprophytes for those non-chlorophyllous Phanerogams which live exclusively saprophytic on organic debris, in contrast to those possessing chloropliyll, which he names Hemi-saprophytes. 4 THE TARASITIC FUNGI. but as a rule they live throughout their whole development as parasites. "Within each of these four divisions one may introduce a number of sul)divisions. H emi-saprophjrtes. The majority of saprophytes are never parasitic, yet there are a number which become so occasionally. Thus some species of Mucor and Penicillium can penetrate into thin-skinned fruits, and this they do the more easily, the further the fruits are from the condition of full vital energy, to use De Bary's expression.^ Eelated to these are other fungi which, although incapable of efiecting entrance into plants in active life, may yet do so as the plant, though still living, begins to wither. In such cases the parasitism is somewhat difficult to prove. In particular, the so-called ' Fungi imperfect! ' contain forms of this kind. Amongst the hemi-saprophytes we may include the species of Botrytis, which are able to penetrate into unfolding parts of plants, but not into the older parts. We may specially mention Botrytis Douglasii as a form more generally known as a sapro- phyte, but which becomes parasitic on immature organs, and which penetrates young needles of various conifers to kill them, whereas it is unable to attack older needles. In this case the thickness of the membranes would seem to act as a protection, just as the vital energy of the plant does in the preceding cases. Tn Sdcrotinia sclcrotiorum, Scl. ciborioides, and Scl. Fuckeliana, a saprophytic existence must, as in the example just mentioned, precede the parasitic condition ; in fact De Bary holds that these forms can only become parasites after their mycelium has been saprophytically strengthened ; the parasitic condition is not necessary to them, for they can go through their whole develop- ment on a dead substratum. Fythimn Be Barycmum is also to be regarded as a hemi-saprophyte which attacks and kills seedlings of many plants as a parasite, but otherwise vegetates on dead plant remains. Cladosporium herharum, one of the commonest of saprophytes, behaves similarly, but it is of less frequent occurrence than Pythium, and in fact its parasitism has only been suspected quite recently. iThis has been confirmed by Davaine (Compt. rend. LXiii.. 1866, pp. 277 and 344) and Brefeld {Siizunf/vber. d. natur/orsch. Fr. zu Berlin, 1875). CLASSIFICATION OF PARASITES AND SAPROPHYTES. 5 As further examples of fungi, capable, as parasites, of killing living cells, but which pass through more or less of their life as saprophytes, may be taken species whose mycelium inhabits the wood of trees and shrubs. Amongst these are numerous PolyiJoreae, which find admission only by wounds in the wood. At first these destroy and derive nourishment from the substance of dead parts of the wood, but later they begin to attack the parenchyma of the living wood, and extending outwards kill, as they go, cambium, bast, and rind, till they reach the exterior, and there develop sporophores. As examples we may take those species investigated by E. Hartig of Munich, e.g. Pob/- pan/s fomentarins, P. igniarius, P. Hartigii, P. sulpharenH, Sfercum hirsutum, Tramctes pini} The heart-wood is a part of the tree generally avoided by insects, which would in very short time destroy the sap-wood with its rich starch-content, e.g. Annohiae in oak. Again, the heart-wood resists the influence of certain saprophytic fungi much longer than the sap-wood, hence it is preferred as the timber used for railway sleepers. Althougli in these cases we might describe the heart-wood as possessing antiseptic properties, yet this would scarcely be accurate, since it is just this very heart-wood which is always first attacked by the wound-parasites of trees, and gives them a hold on the tree as parasites. See also Chap. V. Since these dangerous tree-fungi can live wholly as sapro- phytes in the heart- wood, and in the sap-wood partly as such, partly as parasites, they are also able to vegetate further, and to reproduce themselves on felled stems, especially when the necessary moisture is provided. Thus, for example, Agaricus (idiposns, a wound-parasite of the silver fir, produces its yellow sporophores on felled stems and split wood during the whole summer in moist parts of the forest, while in a cellar or other moist chamber the development of sporophores may continue over a year. In fact, I have found that a billet of beech-wood, after being placed under a glass and allowed to lie completely diy, on again being soaked from time to time, continued to produce a crop of toadstools annually for five years. Some wound-parasites occur occasionally as typical sapro- phytes on dead wood. Thus Polyporus annosus, perhaps better ^R. Hartig, Zersetzungserscheinunf/en des Holzes, 1878) and other works. G THE PARASITIC FUNGI. known as Trametes radicijjerda, is an undoubted parasite of pines, spruces, and other trees, yet on timber in mines ^ it grows luxuriantly, and reproduces abundantly from sporophores, which, however, differ somewhat from the typical form. Again, the rhizomorph-strands of Agaricus mdleus grow under dead bark, in the earth, in mines, and in wooden water-pipes, while other forms of its mycelium are completely parasitic ; thus the apices of the rliizomorphs penetrate the bark of young conifers, and, in the form of a mycelium, live parasitic on rind, bast, and cambium. Polijporus Tajjoraritui, a true parasite on living Scots pine, is also an enemy of timber in newly-built structures, or in subterranean spaces and cellars, so long as it can obtain the necessary moisture. Poh/2)orvs sulpliuyxus produces sporophores on the bark of living trees, as well as on the dead stools of felled trees. Many other related forms would probably be able to live on dead timber if they were not dependent on a certain degree of moisture, and could submit to diying-up as easily as, for example, Polyporvs dbietinus, a true saprophyte, and one of the most common enemies of old wooden bridges. Fungi from other groups are also known to effect an entrance into the wood of trees through wounds only, yet when once in, they spread rapidly, and at length bring about the death of their host. The spores of Cucurhitaria lahurni were demonstrated by me to germinate on the laburnum, on wounds produced by hail and otherwise, and to send into the wood so exposed a mycelium, which spread through the vessels and into the rind, killing all the tissues on its way. Similarly Ncctria cinnaharina, after it has killed its host, lives thereon as a saprophyte, and develops patches of conidia and perithecia on the dead bark. Pcziza WiUkommii, although really a strict parasite on the living- rind, yet continues to grow and to reproduce itself on the dead branches. Hemi-parasites. If the examples already given, i.e. Mncor, Penicillivm, Botrytis, Pythmm, are typical of hemi-saprophytes, then there may arise a doubt whether the remainder, the wood-destroying Polyporeae, Ncctria, Cncurhitaria, and Ayciricvs mcUci/s, should not be regarded ' Harz, Botan. Cenfralblatt, 1888, Vol. xxxvi. ; ^lagiius, Botan. Vtrein d. Prov. Brandevhuru, 1888. CLASSIFICATION OF PARASITES AND SAPROPHYTES. 7 as liemi-parasites. They must, however, be iiichided amongst the hemi-saprophytes, because doubtless they are capable of going through their whole development as saprophytes. The hemi-parasites include, amongst others, the Ustilagineae, all of which live for a time as parasites, and cannot, even by artificial cultivation, be made to complete their life-history as saprophytes. While, however, many of the Ustilagineae are adapted to a com- pletely parasitic life, others can, in the form of sprouting conidia, live and multiply saprophytically. The conidia of Bxobasidiimi and Exoascus continue to bud off conidia for a considerable time in nutritive solutions, yet in nature, the spores probably produce infecting hyphae at once, and the fungus is but little suited to sustain a saprophytic mode of life. Phytophthora infcstans is more easily reared as a saprophyte, and occurs in nature as such, hence it approaches somewhat towards tlie hemi-saprophytes. True Parasites. The Uredineae may be taken as the most typical of the true parasites ; they constantly pass through their whole life-history on living plants, and cannot be cultivated on a dead substratum. So also the Erysipheae, although frequently their spores only reach maturity on a dead substratum, as do also those of Ehytmna and Polystigma. Ergot of grain and the Sclerotinia inhabiting berries, are also truly parasitic, even though their apothecia or perithecia are produced from hibernating sclerotia, and though their conidia can be saprophytically cultivated on dead pabulum. The Peronosporeae and Protomyces are also true parasites. In many other forms the development of germ-tubes, or the sprouting of conidia, may be obtained in artificial nutritive solutions by exclusion of rival fungi and bacteria, yet it is doubtful whether this takes place in nature. § 3. MODE OF LIFE OF THE PAEASITIC FUNGI. The parasitic fungi may be divided according to the place of their occurrence and their mode of attack on the host, into two categories, which may be designated epiphytic and endophytic 8 THE PARASITIC FUNGI. parasites. ^ The former have their vegetative mycelium spread over the surface of the host-plant, the latter penetrate into the plant and there develop their mycelium. Both receive nourish- ment from the cells of the host-plants, generally by means of special absorptive organs inserted into the cells of the host, the so-called hanstvria. We may distinguish the following groups of parasites accord- ing to the degree of their penetration into the organs of the host-plant tliey attack: 1. Epiphytes: {a) with haustoria which only sink into the outer membranes of the host ; {h) with haustoria penetrating into the cavity of the host- cells. 2. Endophytes : {a) with a mycelium which grows in the walls of the host-cell, and is generally nourished without the aid of haustoria ; (J)) with a mycelium which grows in the intercellular spaces only, and is nourished with or without liaustoria ; (c) with a mycelium which penetrates into the host-cells and becomes an intracellular mycelium : (d) lower fungi which live completely in a host-cell. 1. Acquisition of nutriment by the epiphytic parasitic fungi. The simplest mode of acquiring nutriment is found in yeasts {Saccharomyces apiculatus, etc.) which frequent the outside of living fruits, and live on the drops of sugary solution which diffuse therefrom. - ^Epiphytic parasites always produce their reproductive organs outside their host-plant. In the case of endophytic parasites, the reproductive organs of some are produced inside the host-tissue, e.;/. the zygospores and oospores of Chyfridiaceae and Peronosporear, the chlamydospores of the Ustilagineae ; otliers form their sporocarps wholly or partially end)edded, the spores and conidia only being discharged externally ; while a large number form sporocarps on the surface after the epidermis has been torn. Conidia are generally abjointed from the free surface of the host-plant. The terms epiphytic and endophytic parasites have been chosen with regard to the development of the parasitic food-absorbing mycelium. Some authors regard epiphytism somewhat differently, and include amongst endophytes those forms which live on the surface of the host and penetrate only by haustoria. If this be accepted, epiphytism is very exceptional amongst parasites of the higher plants. Zopf {" Die Pilze") gives as examples of this condition only the following: the Lahoulhemaceae inhabiting the chitinous skeleton of certain insects, and Mtlano- spora parasiiua on filaments of species of I>y means of specialised haustoria. Haustoria of the endophytic Parasites. A large number of endophytic parasites frequenting hosts which do not immediately succumb to their attack, possess "haustoria" or special organs for the acquisition of nutriment from the cells of the host. The haustoria are lateral outgrowths of the mycelium with a limited period of growth and a more or less constant form. They are more varied in form, but otherwise quite comparable with haustoria of the epiphytes, especially with those of the Erysipheae. One of the simplest forms of ^ Figures in Fiinijhi Parasitti, Cavara and Briosi. MODE OF LIFE OF THE PARASITIC FUNGI. 13 haustorium on an endophytic mycelium is that exhibited by the parasite Cystoiyus ; the hyphae send oft' very fine filaments which penetrate the walls of a host-cell and swell up to little button-like sacs. Many Peronosporeae (P. irygmaca, P. nivca, P. viticola and Phytophthora omnirora) have haustoria of the form just described, whereas others have them thread-like and branched (P. ealofhcca of the woodruff), or crenately lobed (P. parasitica). Amongst the species of Uredineae and Ustilagineae, haustoria are not uncommon and present many varied forms. They are, however, few in number, or confined to certain parts of the mycelium, so that they may be easily overlooked. Haustoria in the form of long sacs of various lengths are produced by Melampsora Goeppcrtiana in the tissues of both cowberry and fir-needle. Gymnosjwrangmm in juniper has occasionally very delicate button-like haustoria. Endophyllv.m sempcrvivi in the house-leek has haustorial branches which, according to Zopf, are coiled together and anastomose frequently with each other. Ttthurcinia amongst the Ustilagineae possesses short branched haustoria resembling one-sided clusters, and Melanotacnium endoycnum has similar' haustorial-tufts even more branched.^ Urocystis pompholygodcs in Hcpatica triloba has spirally coiled haustorial hyphae, while TiUctia endopliylla, Sorosporium saponariae,^ and many species of Ustilayo, have haustoria \vith the form of knotted hyphae. Amongst the Hymenomycetes, EwhasitUum vaccinii forms a mycelium which permeates the host-tissues with numerous hyphae, but the only haustoria are hyphae which here and there penetrate into a cell. No haustoria have as yet been found amongst the Basidiomycetes,^ Pyrenomycetes, or Discomycetes. The two groups last-mentioned have an inter- cellular or intracellular mycelium, which as a rule quickly kills all cells with which it conies in contact. ^ SenckenbercjiHche vadtr/orsch. Ge.s. Ahhandl. 1880. Plates I. and IV. -Primjsheivis Jahrbiich, 1869. Plates VII., VIII. *Sarauw has figured haustoria in mycorhiza of beech, without however determining exactly whether they belonged to a Hymenomycete. Reess also figures similar organs on mycorhiza produced liy one of the Tuberaceae. CHAPTER 11. EEACTION OF HOST TO PARASITIC ATTACK. The reaction of the host to the attacks of parasitic fungi is fairly constant for the same host and fungus. The various fungi, however, exert on the same host-plant each an influence of its own, while different host-plants behave very diflerently under attacks of the same fungus. § 4. EFFECT OF PARASITIC FUNGI ON THEIR HOST.^ A. Killing of Host-Cells.'- 1. Absorption of living cell-content by parasitic fungi. The lower fungi give us examples of the simplest mode in which fungus-parasites draw nutriment from their host-cells ; particularly those forms parasitic on algae or other fungi. The most primitive of all are numerous species which, applying themselves to a host-cell, bore through its walls and enter the cavity. There they derive nutriment at the cost of the living cell-content, — the plasma, cell-sap, chloroplasts, starch grains, etc., — and finally kill the cell. The host-cell does not survive the later development and reproduction of the parasite. The effect of the fungus is however limited to the ' Billroth ("liber die Einwirkungen lebender Pflanzen iind Thierzellen aufeinan- i\er," Samm/un;/ Medic. Schri/ten. Wiener klin. Wochenb/atf, 1890), compares in a masterly way the effects of micro-organisms and of injuries on animal and vege- tal)le tissues. He employs Virchovv's terms "formative stimulus " and "formative irritability " ; the former to denote the capacity of micro-organisms in producing outgrowths of definite form or the formation of new tissues ; the latter, the capacity of the tissues to react to such stimuli, and to produce outgrowths, etc. A comparison of the external phenomena of fungoid diseases in the case of animals and plants recently formed the subject of a short paper by Lewin. - Perniciasmus. EFFECT OF PARASITIC FUNGI ON THEIR HOST. 15 cell attacked which is at once killed before it can enlarge or otherwise react to the influence of the intruder. Good examples of such parasites are presented by some of the Chytridiaceae — the Archimycctcs of Fischer — which, as a rule, inhabit only isolated cells of their respective host-plants. This mode of nutrition is equivalent to that of the Myxomycetes and Mycetozoa, which absorb the cell-contents after completely enveloping the living cell, or after slipping inside or sending a haustorial process into it. A second series of parasites consists of those which live on the contents of the host-cell, and give it time to react to the stimulus exerted by the intruder. The reaction generally results in a cell-enlargement or fungus-gall, which in the simpler cases includes one , cell only. The gall harbours one or more parasites, which gradually use up the cell-contents. As examples we have Olpidium tumaefaciens and 0. uredinis} Pseudolpidium saprolegniae, Olpidiopsis saprolegniae, RMzomyxa liypogaea} etc. A specially striking case is that of Plcotrachelns fulgcns, which causes the rudiment of the sporangiophore of Piloholus Klcinii to become hypertrophied and gall-like.^ We have as a third series those parasites which penetrate into living cells and absorb their contents, at the same time stimulating the host-cell to abnormal and increased growth, as well as some surrounding cells not directly in contact with the fungus. In this case the parasite exerts a far-reaching effect, and produces a gall composed of more than one cell. Species of Synchytrium are examples. The fungus itself penetrates into one cell only, which enlarges ; but simultaneously the surrounding cells grow and multiply to form a wall or rampart enclosing the cell originally attacked. Other parasites do not absorb the host-contents as a whole, but only withdraw osmotic substances by means of delicate processes of the fungus-hyphae. These haustoria penetrate the wall of the host-cell, but the fungal protoplasm inside them remains separated from the host-proto- plasm by a delicate membrane. In the case of the vine-mildew and some other Erysipheae, the cells thus preyed on turn brown and die. With other related forms {e.g. Sphacrotlieca castagnci), ^ See Fischer's Phycomycefes. - This causes a slight swelling of the root-hairs of various plants and absorbs their content. ^Zopf, Be.itrd(j€ zur Physiol, u. Morphol. nied. Organismen, ii. 1892. 16 REACTION OF HOST TO PARASITIC ATTACK. absorption by haustoria results in a deformation and distortion of attacked organs, which euibraces even cells far distant from the point of attack, yet without death following directly to any cell. 2. Absorption of cells or tissues by parasitic fungi. The total absorption of cells or tissues by parasitic fungi constitutes a special form of cell-destruction. Cases of this kind occur particularly amongst the Ustilagineae. Thus Urocystis violae so stimulates the cells of Viola that they divide and produce a delicate tissue, rich in protoplasm ; this nutritive tissue is used up when spores are formed, but without any great detriment to the host-plant. At the time of spore-formation of other Ustila- gineae a great destruction of the host-tissues may, however, take place ; this is especially marked in attacks of Ustilago maydis, U. avcnac, Tilldia tritici, on the ovaries of their respective hosts, as well as in other cases to be considered later. 3. Killing of host-cells and tissues by fungi which excrete ferments. The simplest case under this heading is presented by species of Sdcrotinia studied by De Bary, e.g. Scl. scUrotiorum. The mycelium of these, while still lying on the outer surface of the host-plant, excretes a ferment which sinks through the mem- branes into the cell-cavities, caiising death to the protoplasm and even destruction of whole tissues. A similar process may be assumed in the case of numerous fungi with a mycelium which grows only in the intercellular spaces, yet causes immediate death to any cell it may touch. This is the case with many leaf-spot diseases, like, those due to Cercos2wrn, Hysterium, etc. So also do the apices of rhizomorph- strands kill portions of the bast of living Conifers with which they may come in contact. The rapid death of tissue following the attack of such deadly fungi as PhytopMhora is probably due not altogether to the deprivation of nutriment, but also to the effects of a poisonous excretion. This, however, has not as yet been satisfactorily ascertained. B. Killing of Organs or Whole Plants. A large number of fungi have a mycelium which never ex- tends beyond a very short distance round the point of first infection, and causes only local disease, frequently with no EFFECT OF PARASITIC FUNC4I ON THEIR HOST. 17 perceptible disturbing effect on the liost. Such is the case particularly with leaf-spot diseases ; the tissues of isolated spots are killed and fall out, the leaf appearing as if perforated by shot, but otherwise exhibiting no discoloration or other symptom of disease. In contrast to these there are fungi w^hich, directly or indirectly, bring about death of their host or some part of it. The simplest example of parasitic fungi killing their host directly is presented by one-celled or few-celled plants, which soon succumb to attack even on a single cell. Where, however, the host is a highly organized plant, its organs will resist the attack of the parasite for some time. Thus with Phytophthora fagi, the mycelium spreads rapidly through the tissues of a seedling, so that death ensues in a few days. Similarly species of Peronospora rapidly kill leaves, branches, and fruits ; likewise Cladosporium , Sqytoria parasitica, and others. Somewhat different in their action are those fungi which kill some tender part of a plant directly, and thereby in- directly further the death of other parts dependent thereon. As examples, take Pcstalozzia Hartigii (Fig. 301) and Plioma abietina (Fig. 293), which kill only some small portion of a young plant or branch, but thereby cause drying-up of higher or distal parts. Gibhcra vaccinii on stems of cowberry (Fig. 95) is another example. Similarly cankers arising from Nectria ditissima (Fig. 80), or Peziza Willkommii. Again, Agaricus mcUcv.s and Trametes radidperda kill roots or lower portions of the stem, and bring about the death of trees of all ages. The case varies somewhat with certain wound-parasites like Nectria cinnalarina and Cucnrhitaria lahurni. There the my- celium extends so vigorously in the water-conducting organs, as to kill them and fill up the vessels, causing thereby so serious a disturbance in conduction, that branches or whole plants wither away in summer. The wood-destroying Pohjporcac and Agaricini act similarly, although more slowly ; they attack large branches and stems, destroying all parts of the wood, duramen as well as sap-wood, and finally the bark. There are also cases where organs of the attacked host remain alive, but suffer on account of the hypertrophy of other parts. In this way portions of a plant may be killed although not directly the seat of the parasite. This is particularly the case where hypertrophied organs undergo increased growth and p. 18 REACTION OF HOST TO PARASITIC ATTACK. Utilize the water which would otherwise have ascended to higher parts of the branch-system (Fig. 3). It must indeed be assumed that the latter are preyed on by the hypertrophied parts and give up plastic material, which they would otherwise have utilized themselves or stored up as reserve material. On branches attacked by mistletoe and other phanerogamous parasities, it can easily be observed, particularly on broad- leaved trees, that a supporting branch grows vigorously in the parts under the influence of the root-system of the parasite, whereas the distal parts of the same branch-system remain stunted and finally die. The mistletoe-bush thus comes to form the termination of the supporting branch. If, in consequence of this, the branch ceases to produce the leaves necessary in preparing food for it, then like every other leafless branch it dies. Such branches carrying leaves of the mistletoe alone may frequently be found on firs, pines, and broad-leaved trees ; even whole tree-sunnnits have been seen on the silver fir with every branch terminated by a mistletoe-tuft, not unlike some huge candelabrum. In a similar manner a witches' broom, developed from a lateral bud, exhibits throughout an increased growth, while the branch supporting it remains thin and dies from the insertion of the broom outwards. So also in attacks of Gymnosporangium on juniper it may be observed that the parts attacked have their growth much accelerated and many of their dormant buds developed, while the distal parts of the same branch die oft'. In all such cases it is quite probable that, as the distal parts die back, any food material which they may contain finds its way into the hypertrophied region. C. Shortening of Life. IVfany fungi inhabit a plant without disturbing the develop- ment of any part or causing immediate death, yet with such effect that the vegetative period of the organ in question terminates earlier than normally. A very striking example of this is presented by the needles of silver fir on the witches' brooms caused by Accidium elatinum. The needles normally vegetate for several years, but when influenced by this parasite they live only a single season. So also needles of spruce attacked by Accidium cor- EFFECT OF PARASITIC FUNGI ON THEIR HOST. 19 Fio. li.—E.i-ooscas cerasi. Witches' broom of cherry. The supporting branch is dead from its apex backwards to the seat of an infected lateral bud, which has developed into a witches' broom. On the tree the supporting brunch pointed slightly more downwards than is shewn. J natural size. (v. Tubeuf phot.) 20 REACTION OF HOST TO PARASITIC ATTACK. uscans, which may, in addition, bring about death of the whole shoot. Needles of spruce beset by aecidia of Chrymmy.ra rlwdodcndri are cast after reproduction of the fungus in August or September, while with Chrysomyju ahietis the needles of Conifers fall in May. The latter examples diff'er somewhat from the former in that the mycelium lives in the witches' broom for years, and continues to send out new shoots with deformed needles, whereas in the Chrysomym attack the my- celium is confined to the needles and falls with them. Examples from other groups of fungi are the witches' brooms of Alnus incana caused by Exoascus cinijhyllus. The leaves of these are fully developed though somewhat modified in form ; their life-period is, however, shorter than that of normal leaves, and they fall earlier. It may be observed here that this phenomenon of premature defoliation is one recorded as a consequent of many parasites. The witches' broom twigs of the alder grow and produce buds almost normally, yet the whole broom-system dies in a few years, and long before the normal life-period of the tree. The war of extermination by mycelium against host-plant may frequently last for a very long time. Hartig gives an example of a larch which had carried on the combat with the larch-canker (Fcziza Willkommii) for over eighty years, l)ecause during active vegetation of the host the parasite was unable to make headway. D. Premature Development of Buds. The unfolding of buds in spring in advance of those of normal plants is also a feature of many diseased plants. This is manifest in the earlier unfolding of buds on witches' brooms of the silver fir and cherry. The alder witches' broom, already referred to, is however exceptional, in that its buds open after those of normal twigs.^ A premature flowering may also result, so that flower-buds formed in summer unfold the same autumn instead of during the following spring. Thus in a recent autumn a violet opened in a plot in the garden of Professor Hartig in Munich. The flower was found to be somewhat stunted, and its stalk beset 1 Smith, " Untersuchuiigen d. Aiiat. u. Morpli. der tlurch Exoasceen veru- sachten deforniationen." Inaug. Diss. Muuicli, 1 894, p. 1(5. EFFECT OF PARASITIC FUNGI ON THEIR HOST. 21 by pustules of Urocystis violac, the mycelium of which had perennated in the stem. Kerner in his '•' Pflanzen-leben " ^ mentions a similar case where flowers of Primula clusiana and F. minima attacked by Uromyces 'primulac integrifoliae unfolded prematurely in autumn. E. Preservation of the Host-Plant and of Host-Tissues. (Conservation.) In contrast to those parasites which attack a plant, or parts of it, and immediately kill it or otherwise exert a direct destructive influence, we have these which live for a longer or shorter period with their host without producing such an effect. Cohabitation of this kind may last only for a short time and terminate with the first reproductive period of the fungus, or it may last for years as a perennating symbiosis, or as a perpetual one like that of lichens. This phenomenon is particularly conspicuous amongst the Uredineae. These throughout their whole development adapt themselves to an existence with living host-cells, so that the latter die only after the reproduction of the fungus. Frequently the mycelium lives in perennial organs for a length of time, even for many years. The attacked parts are of course injured to a certain extent, and hypertrophy of the most varied kind, accompanied by characteristic phenomena, may take place, yet this only towards the termination of the period of development. The Ustilagineae are in a similar manner adapted to an exis- tence in living organs, and there produce their spores. At the time of spore-formation and liberation they are deadly enemies of their host-tissues, yet previous to this they vegetate in the living tissues with little or no apparent injurious effect. Some like Ustilaffo perennans, even pass the winter in the living host- tissue without killing it. The individual species of the Hysteriaceae, Discomycetes, Tyrenomycetes, Hymenoinycetes, and lower fungi differ ver^ much in their action ; many of them inhabit living tissues for a length of time without injurious effect, while not a few, like the Exoasceae, even perennate from year to year. The galls pro- duced as a result of Exohasidium do not die till the fungus has reproduced itself. It is unnecessary at this place to give details ' English Edition, Natural Hi'^tory of Plant H (Oliver), II., p. o2.'5. 22 REACTION OF HOST TO PARASITIC ATTACK. of Other examples, since many of these will be referred to again in other chapters, particularly wlien hypertrophy is under consi- deration. § 5. EFFECT OF PARASITIC FUNGI ON THE B^ORM OF THE HOST-PLANT. 1 . Arrest of growth, and Atrophy. While a large number of fungi produce more or less extensive enlargement of parts of their host, others cause arrest of organs, crippling, impoverished nutrition, and even atrophy of an extreme kind. Incompletely developed organs of this kind may originate even where the fungus in possession produces only local hypertrophy. In- teresting examples are presented by many species of Syndiytrinm {e.g. S. taraxacum and S. ane- mones). The former is endo- phytic in Tai'axacum, and exerts a stimulus resulting in increased growth, not limited to the single ceil attacked, but ex- tending to neighbouring cells, which, in consequence, multiply and form a ring-like swelling round it. The leaves as a whole, however, are poorly developed, so that the lamina in very extreme cases may be represented only by the midrib and narrow margin (Fig. 4) ; while on leaves attacked on one side, that side alone is stunted, the other is normal. Taraxacum leaves badly attacked by Fuccinia are not at all deformed, whereas those of Anemone show striking arrest of growth (Fig. 190). Leaves of Cirsium attacked by Fuccinia snaveohns exhibit an arrest of the same kind, remaining less divided and of softer texture (Fig. 186). Flowers affected by parasitic fungi present many striking, malformations. Magnus ^ describes such a case in Anemone ' Magnus, " Einfluss v. Parasiten auf d. Ausbiltlung d. befalleiien Pflcinzen- theiles." Natvrwhs. Riindschau, 1891, No. 2o. Fig. 4. — Synchylrium taraxaci. Partial atrophy of laminae of 7'araxacum officinale. About i natural size. (v. Tubeuf phot.) EFFECT OF PARASITIC FUNGI ON THE FOKM OF HOfeT-PLANT. 23 mmmmloidcs under the influence of Accidnim pundaivm. ,Iii the simpler cases the floral leaves were narrow, elongated, and greenish, stamens were foimed but not carpels ; in more pro- nounced cases, the petals were only represented as small, simple, Fn;. 5. — Clierrv tree in (v. Tubeuf phot.) stalked, green leaves, the stamens were reduced in number and there were no carpels. One case exhibited, in place of a flower, only two leaflets terminating the flower-peduncle, one of them palmately divided. 24 REACTION OF HOST TO PARASITIC ATTACK. True atrophy is best seen in those cases where iiower-iornia- tion is suppressed. This effect of parasitic fungi on their host is by no means uncommon, the fungus alone reproducing itself, while the assimilating host-plant remains sterile. This atrophy is found not only in annual plants, but also in those where the symbiosis iniglit be designated as perennial. The last-mentioned case is exemplified in Accidium clatinum, the witches' broom of which never bears flowers ; again, by witches' brooms of Ejonscus Fig. G. — Euphorbia Cj/parissias. A healthy flowering normal plant compared with the attenuated non-flowering form inhabited by Aecidium euphorbiae. (V. Tiibeuf phot.) ccrasi (Fig. 5), which bears only leaves when the rest of the tree is in blossom. Another perennial symbiosis behaving thus is shown in Eupliorhia Cyparissias attacked by Accidium euphorbiae ; year after year the diseased shoots produce only leaves, which assist in the reproduction of the fungus (Fig. 6). Similarly with many other Uredineae. Arrest of the seed occurs in ovaries of species of Pnnius under the influence of Exoascl (Fig. 7). In flowers attacked by Ci/sfopu,s LiBRABX EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 25 the ovules become atrophied, whereas the rest of the flower is hypertrophied. Similarly witli fiowers of cowberry deformed Ijy Exohasidiain. 2. Hypertrophy. — Alany para- sitic fungi cause abnormal enlarge- ment or other malformation of plants which they attack. The simplest case of hypertrophy is seen in the enlargement of a uni- cellular plant as a result of an endophytic parasite, ejj. Pi/oho/ i/s Kh'inii with Plcufmclirhis. The same example is also the simplest possible case of a gall caused by a plant, and distin- guished by the name of " fungus- galls " or Mycocecidia, from Zooce- cidia, the galls caused Ijy animals. Larger galls occnir on leaves attacked by Synchjjtriiim, where not only the single cell attacked becomes enlarged, but also the surrounding cells ; these galls, however, form but tiny points on diseased leaves. Similar small and local enlargements of the leaf-cells, accompanied frequently by cell multiplication, are caused by many other fungi, ejf. species of Exoascm. More extensive malformation may embrace some part or even the whole leaf, so that it is more or less enlarged and beset with blister-like outgrowths, as with other Exoasceae (see Figs. 62 and 64). Other gall-forms are presented by ExohasicUum on the alpine-rose (Fig. 259), where the gall is always localized to a small area of the leaf, and on the cowberry, where the gall may extend over whole leaves, and even include the shoot (Fig. 256). Hypertrophy of the whole shoot, resulting in elongation and thickening of the twigs, is a phenomenon frequently met with in the " witches' brooms," to be referred to later. And just as entire branch-systems may become hypertrophied and elon- gated, so may whole plants, if the mycelium, instead of remaining localized, spreads throughout the plant. Examples of this will Fig. 7. — Fruit of plum deformed by Exoa$cus pruni ; the stone is shrivelled and abortive. 4 natural size. (v. Tubeuf phot.) 26 REACTION OF HOST TO PARASITIC ATTACK. be described when we consider Euphorbia with Aecidium euphorhiae (Fig. 6), house-leek with Endophyllum, anemone with Aecidium (Fig. 190), and cowberry with Calyptospora (Fig. 202). Where plants, like the cowberry and anemone, live in com- munities, tlieu these elongated individuals rise above their healthy neighbours, and the fructifying fungus has a better chance of having its spores distributed by wind. It must, however, be observed that when hypertrophy of a whole shoot or plant occurs, every part need not be enlarged to a propor- tionate extent ; in fact some parts generally remain abnormally small, e.g. leaves in cases of rusts upon cowberry, fir, anemone, and others. On the other hand, both shoots and leaves may be abnormally enlarged, as in cases of alder with Exoascus Tosquinetii or Em. ejnphT/Uiis.'^ Hypertrophy of the roots occurs on alder, where large tubers are produced by Frankia (Fig. 21). On Leguminosae, tubercles of various sizes are caused by Rhizohium (Fig. 22). Roots of J uncus develop thick-lobed outgrowths as a result of Schinzia (Fig. 179). Eoots of turnip infested by FlasmodiojjJiora have irregular swellings of all sizes (Fig. 315). Mycorhiza frequently exhibit tubercles or balls formed by the massing together of very short dichotomously branched rootlets into clumps (Fig. 18). Cycad-roots, under the influence of RhizoMum and Nostoc, also exhibit hypertrophy.^ We shall now proceed to consider hypertrophy of the repro- ductive organs, and at the same time to notice some other changes induced in the flower by parasitic fungi. Influence of parasitic fungi on the development of reproductive organs of host-plant. Disease of the flower and fruit, when not caused by fungi •which kill the cell, generally causes striking floral malformation. These we may group as follows : 1. Atrophy or total suppression of flowers. 2. Arrested development of flowers. 3. Development of rudimentary organs, 4. Abnormal formation of flowers. 5. Hypertrophy of parts. 0. Transformation into sclerotia. ' 8ee also § 7. - Schneider, Botanical Gazette, 1894, p. 25. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 27 The two first cases have already been considered. The arrest of the flowers of anemone, as a resvilt of Accidmm i^wiciatum, is a further example of Case 2, and at the same time exemplifies Case 4, in that the floral leaves become green foliage leaves, though of a very stunted kind. The petals of Cruciferae hyper- trophied under the influence of Cysto'piis candidus often become green, and at the same time much altered in shape. A particularly interesting case is presented by the develop- ment of the stamens of the pistillate flowers of Lychnis dioica infested by the mycelium of Ustilago violacea. These stamens normally remain rudimentary, but in the diseased abnormal flowers become fully developed like those of the staminate flowers, except that the spores of the parasite replace the pollen in the anthers. Giard^ has designated this phenomenon as " castration parasitaire," and he distinguishes three modifica- tions amongst unisexual flowers. {a) Stamens appear in pistillate flowers ("androgene castration parasitaire "). This occurs, as already mentioned, in pistillate flowers of Lychnis dioica frequented by Ustilago. (b) Ovaries are developed in staminate flowers (" castration thelygen "). Examples : Carcx praccox with Ustilago caricis, Btichloe dactyloides with Tilldia luchloeana, and Androioogon provincialis with Ustilago androj^ogonis. (c) In flowers of either sex the sexual organs of the other appear in consequence of the influence of the parasite ("amphigene castration parasitaire "). Giard compares these cases with that of the development of the organs of the latent sex in animals, e.g. of cock's feathers on an old lien, or growth of horns on castrated or " gimmer " animals. In both cases the phenomenon is due to the same cause; in the animals the organs of the latent sex appear as the result of the normal organs becoming functionless or being destroyed by castration ; in the plants through stimulation of the latent rudiments by the fungus, which does not, however, cause suppression of the organs already present. In some respects the phenomenon is comparable with what happens when the terminal shoot of a tree is lost and some neighbouring lateral shoot turns vertically upward to replace it. The eff"ect of fungi on the reproductive organs of plants 'Mangin ami (Hard, Bulletin scient. de la France et de la Behjique, 1884. 28 REACTION OF HOST TO PARASITIC ATTACK. may also be seen amongst lower cryptogamic plants, two cases of which may be mentioned here.^ Plcotrachclus ftdgcns, inhabiting the mycelium of Piloholus lUcinii, causes the formation of galls and the suppression of sporangia, while at the same time zygospores, normally rare, occur in large numbers. Likewise a species of Synccplialis parasitic in Piloholus cnjdal linns causes suppression of sporangia and stimulates formation of zygospores. The transformation of tioral organs may reseml)le that observed by De Bary, in which, as a result of attack of Pcronospora violacea on Knautia arvensis, the stamens appeared in the form of violet petals. Doubling of flowers is also caused, as in Saponaria officinalis, under the influence of Ustilago saponariae, and Cornpositae with Pcronospora radii. The Ustilagineae, perhaps, cause the greatest amount of varia- tion on the flower, because many of them produce their spores in the floral organs of their host. Thus, in the anthers live Ustilago violacea, holostei, scabiosae, intermedia, succisae, hetonicae, 'major, scorzonerac, capcnsis, pinguicolac, Vaillantii, and Tuhvrcinia primulicola ; the last named also occurs in ovaries and stigma. So also do many others inhabit the ovary or some other part. Many, like Ustilago mayclis, form spores throughout the plant as well as in the flower, and bring about hypertrophy and destruction of parts. Amongst these are Ustilago avenae, pcrennans, hordei, nuda, tritici, panici miliacei, reiliana, crncnta, sorghi, Crameri, caricis, tragopogonis, Tilletia laevis, etc. Cystopus (Fig. 35) causes very characteristic hypertrophy of all parts of the flower, particularly an enormous outgrowth of tlie ovaries and floral envelopes, whereas other parts are arrested in their growth. Wakker investigated a number of Cruciferae with flowers deformed by this parasite, and found variations in the form and anatomy of the deformations produced on the different host-species. ExobasidiiLm also causes well-marked hypertrophy of flowers, and even of the whole inflorescence of cowberry. Woronin ^ describes and figures such cases (Fig. 256). All parts of the flower may be attacked and grow to a great size, becoming 'Zopf., Bdtru(ie zur Physiol, unci Morph. niederer Ory the resting-mycelium of some species of Sdcrotinia. Formation of new Organs. Although parasitic fungi commonly induce hypertrophy of existent organs and development of normal latent structures, they are seldom associated with formation of new organs. As such, however, we must regard the formation of adventitious buds on the fronds of Pteris quadriaurita, Eetz, and Aspidium aristatum, Sw., under the influence of Taphrina Laurencia, and T. Cornu cervi, respectively.^ Buds or bulbils of this kind occur normally on several species of ferns ; but in those just mentioned they appear only as a result of the parasite, and ■ develop into structures reminding one of a witches' broom. ^ Giesenhagen, Flora, 1892. 30 REACTION OF HOST TO PARASITIC ATTACK. Still more striking are certain structures resembling witches' brooms, which are produced on Thujopsis dolahrata in Japan, under the influence of the mycelium of Cacoma deformans (Fig, 8). These consist of leafless non-chlorophyllous axes, dichotomously branched, and with each branch ending in a disc. They arise from shoots or leaves of the Thujopsis where structures of the kind would never have arisen normally, and are wholly sub- servient to tlie reproduction of the fungus, which forms its sori under tlie epidermis of the terminal discs. Fig. S. Caeoma defrriuans. The nest-like structures are muoh-branclicd, leafless shoots with each of their twigs ending in a caeoma-disc. (v. Tubeuf phot.) The galls produced by Usfilaf/o Treubii on Polyfjonum Sacclm- lincnsc are particularly interesting. Here, as a result of the presence of the parasite, there are formed the so-called vegetative canker-galls, and in addition, the fruit-galls, new organs derived from lateral outgrowths of the host-plant, and of use only in the spore-formation of the Ustilago ; they contain a special capillitium-like tissue, and serve e.Kclusively for the shelter and distribution of the fungus-spores. EFFECT OF PARASITIC FUNGI ON THE FORM OF HOST-PLANT. 31 Somewhat doubtful cases are the outgrowths resembling aerial roots which arise on Laurus canaricnsis attacked by Exohasidimn lauri. Geyler, their discoverer, regarded them as deformed stem- shoots, but they resemble rather the galls of the alpine-rose. § 6. EFFECT OF PARASITIC FUNGI ON CELL-CONTENTS. The most common and, at the same time, most apparent effect of parasitic fungi in this direction, is the stimulation to cell-division and cell-multiplication. This occurs chiefly in young tissues, or in those still in process of growth, and gives rise to numerous peculiar outgrowths and swellings, some of which have already been referred to. The parenchyma of mature tissues may also exhibit secondary cell-division, when under the influence of a parasitic fungus. This I found to be the case in leaf- petioles of Umbellifer^e attacked by Pwtomyces macrosponis (Fig. 9). The epidermis and vascular bundles are never disturbed, but the intervening tissues are permeated by an intercellular mycelium, which causes the cells to divide into a large number of delicate-walled chambers, , . . Fig. 9.— Secondary cell-division all COntammg nuclei smaller than those in parenchyma of petiole of ^<;6ro- . . 2wdium as a. result of Protomi/ces of neighbourmg undivided cells. The maavsporus. The nuclei of the '- . . new cells are much smaller than same thing is observed in plants of those of the primary cell. (Com- rr- 7 J , • -U 1 -^ 1 1 TT ,- pare Fig. 47.) (v. Tubeuf del.) Viola odorata inhabited by Urocystis violae ; the mature parenchymatous cells become divided up by means of delicate walls running in various directions into numerous chambers or secondary cells, which Wakker in describing has named " nutritive tissue." ^ This new tissue remains permanently in attacks of Protom.ifces, but with Uro- cystis it is almost completely used up during the formation of spores. In some diseases caused by Exoasceae, a similar secondary cell-division takes place ; for example, in the sub- epidermal parenchyma of leaves of poplar with Tcqohrina aurca (Fig. 63). An interesting observation was made by Rosen ^ on the direct ^Wakker, " Untersuchungen. " Pringshetm's Jahrbuch, 1892. -Rosen, Beitriirje z. Kenntniss d. Pflanzenzelle. Habil.-Schrift, 1892. 32 REACTION OF HOST TO PARASITIC ATTACK. effect of haustoria of Uredineae on the cell-nucleus. He describes it thus : " The mycelium of Puccinia asarina permeates between the cells of the leaf-tissue of Asarum, and sends into almost every cell of the infected part, a short, sometimes branched, hypha, which serves as a haustorium. This grows in almost every case towards the nucleus of the host-cell, and becomes firmly attached thereto, or completely encloses it. The nucleus, in consequence, undergoes considerable deformation, sometimes being tightly constricted by the haustorium, or the apex of the hypha penetrates deep into the nucleus, pushing the nuclear membrane before it." Enlargement of the cell-nucleus occurs, according to Frank, in the cells of the root-tubercles of Leguminosae caused by bacteria ; likewise in the cells of endotrophic mycorhiza of orchids. Schlicht,^ in considering the endotrophic mycorhiza of Paris quadrifolia, says, " One observes here, as in the mycorhiza of the Orchideae, that the cell-nucleus, which is very large, can exist in the cell beside the fungus-tissue. The hyphae, however, frequently penetrate into the cell-nucleus, or surround it in a close network," ^ The effect of parasitic fungi on the chlorophyll of tissues attacked by them is very varied. We may distinguish three cases, apart from those in which the parasite kills the host-cell and its chlorophyll along w4th it. In the first, the green parts of the plant attacked become bleached by the influence of the parasite, and ultimately lose their green colour ; this we might designate " mycetogenous chlorosis." Examples are the galls of cowberry and species of rhododendron, the results of many Uredineae, such as Clirysomyxa rlwdodcndri on spruce, Accidimn urticac on nettle, Gymnosporcingium clavariacforme on hawthorn, and the leaf-galls due to Exoasceae. In the second case, there is a preservation of the chlorophyll in places infested by the fungus, in contrast to adjoining normal ' Schliclit. "Beitrage z. Kenntniss d. Verbreitung u. Uedeutung d. Mycorhizen." Inaug. Diss. 1889, p. 14. -Groom ('■'■ Thinmia Aseroe and its Mycorhiza," Annals of Botany, June, 1895, p. 339) describes and figures a similar case. He says, "The fungus enters the cell as a single slender hypha, which at once grows directly towards the nucleus of the liost-cell." He also mentions an observation of Professor Marshall Ward, "that in Ilrmiltia of the coft'ee disease, the haustoria often ajjply themselves to the nuclei of the host's cells." (Edit.). EFFECT OF PARASITIC FUNGI ON CELL-CONTENTS. 3S parts, which become pale and die. This is exemplified in Cronartvum asclepiadcum on the leaves of Vincetoxium, Crym- nosporongium clavci.riaeformc on the quince, Uncinula accris on the Norway maple, Rhytisma punctatum on Acer spicatum. Intermediate between these two extremes are cases where the chlorophyll is retained, but in much reduced quantity. For example, organs under the influence of Exoascus alni incanac or Accidium elntinum, though still green, are pale in contrast to those normally deep green; leaves attacked by Peronosporeae, e.g. Corydalis or Anemone with Plasmopora pygmaea, and Anemone with Aecidinm punetatum or Puccinia fnsca\ leaves of Cirsium containing mycelium of Puccinia suaveolens ; leaves of alder with Exoascus epijjJiyllus, and many others. This paler coloura- tion of diseased plants is frequently an easy means of recognizing them amongst the healthy ones. The third case is that of " mycetogenous chloranthy " or the development of green colour in organs normally of some other colour. Wakker has proved this in the petals and stamens of Brassiea nigra and Sisymbrium p)annonicum attacked by Gystopns and Peronospora. Likewise Magnus showed its existence in flowers of Anemone ranunculoides with Aecidimn inmctcdum. The cell-sap, in some cases of hypertrophy, assumes on the sunny side a rose colour ; thus in galls caused by Exobeisidijim on alpine-rose and cowberry, pear-leaves with Roestelia ceincellatet and Polystiejma ndyrum, catkins of alder attacked by Exoascus, and galls caused by Taphrina carnea on the sweet birch. The epidermal galls, due to some species of Synchytrium {S. ruhro- cinctum, S. anemones, etc.), exhibit an intense carmine coloui. Yellow coloration occurs, according to Wakker, in nettle, buck- thorn, and many plants when frequented by Uredineae. There may also be a yellow colour due to the yellow oily contents of the mycelium shining through the host-tissues, as in spruce- needles with Chrysomyxa ahietis. In considering the effect of parasitic fungi on the starch- contents of the host-plant, two very distinct cases may be observed. There may be, for a time, a greater accumulation of starch in the attacked parts than in the normal, or the parasite may dissolve any starch present and utilize it at once. 34 RKACTION OF HOST TO PARASITIC ATTACK. Accuiiiulatioii of starch is described by R Hartig ^ in spruce- needles attacked by Zophodermium macrosporum. In the pre- sence of the fungus-mycelium, an increased production and storage of starch takes place at a time when it is being only slowly formed in normal needles. If the needles become diseased during May, a season when they are already full of starch, this remains intact in the dead cells till Octoljer, wlien it begins to be used up. Wakker ol)served accumulation of starch in cumfiey with Accidium aspcrifolii, in buckthorn with Accidium rhamni, in hawthorn with Roestclia laccrata, in Sispnhrium officinale and other plants with Cystopus, in roots of Brassica inhabited by Plasmodiophora brassicae, and in hypertrophied scales of alder catkins with Exoascus. Many other examples are gi\-eu through- out the literature of plant-pathology. Particularly noteworthy is a case of starch preservation in ■oak-wood destroyed by Polyporus dryadeus and P. igniarius simultaneously.'^ In the wood infested by either of the fungi alone the starch is dis- solved, but at the l)oundary where the two meet it remains in the medullary rays ; these, in consequence, appear snowy white, i| ; 1 and consist almost exclusively of unchanged ^ <, starch-grains, while the lignified cell- walls S ! 'I have been converted into cellulose or coni- I; j-^ pletely absorbed (Fig. 10). Loew^ remarks in \-:. regard to this: "One must assume here a '|; j ;,) variation in the kinds of diastase, and a ' 7 '1; ;' ..' neutralizing effect of the one on the other, in somewhat the same manner as pepsin acts on ty rosin. One is also reminded of two optical antipodes which easily unite into an i.f'^ak-wwd 'destroyed 'by Optically ucutral body " {e.g. sugar isomers). stiif^fuir'''of^undfssoived The dissolutiou of starch by fungi has (v"T,'^eu7;ro?r'"'''" Ijeen examined in detail by Hartig. The wood-destroying fungi dissolve the reserve starch-grains laid up in the wood-parenchyma in various ways. Assuming the view of Naegeli, that starcli-grains consist of a 1 Wichtiije. Kranhheiten d. Waldhdumcn, 1874. 2R. Hartig, Zersetzungtierscheimmijen, 1878. ='Loew, 0., Ein naturliches System d. Gift- Wirkiiuffen. ]Miiiiieh, 189.'}. EFFECT OF PARASITIC FUX(4I ON CELL-CONTENTS. 35 cellulose and a granulose part, Hartig describes the process thus (Fig, 11). The mycelium of species like Polyimms igniariuti gives off some ferment which dissolves the starch-grains, by cor- roding them from the outside inwards, so as to form holes and canals similar to those in starch-grains in process of dissolution in the cells of a sprouting potato. In others, r.(j. TJielephora j^crdii:, the granulose is first dissolved from without inwards, so that finally only the starch-cellulose remains, occupying a region ^^^ u.-starch grains f.-om the oak, in pro- t-.iwflvrlq f-liP ontpr i^nrfcj nf cess of dissolution by ferments, o, of r/,«/tyW.om lOWaiQS tne OUiei parts OI ,,erdix\ b, ot Polnporm sulphureas; ,;, ui P„ly rl-iP trrnin oha.sidinm is not present in crystal-sacs, as in the non-deformed organs, but as ill-defined solitary crystals of limited 36 REACTION OF HOST TO PARASITIC ATTACK. iiinnber ; on the other hand, crystal-sacs, normally absent, are, under the influence of E.voascus cdni incanac, formed in hyper- trophied catkin-scales of alder. It may l)e here observed that calciuui oxalate crystals are found in tlie mycelium of many fungi. De Bary^ found them very common, ))articularly in the mycelium of species of Botn/tis, and he remax'ks thereon : " it may well be assumed that the oxalic acid is formed fi'om the sugar inside the living oxygen -absorbing fungus-cell, but is immediately ejected therefrom by the carbon dioxide produced in respiration ; in other words, an oxida- tion-fermentation takes place in the plasma of the mycelium. The oxalic acid is probably separated in combination with potassium and converted into calcium oxalate, when calcium is present in the pabulum of tlie mvcelium.'"' 5; 7. EFFECT OF PAEASITTC FUNGI ON THE CELL-WALL. The effect of the mycelial hyphae of parasitic fungi on the cell-wall may be either mechanical or chemical. The intra- cellular hyphae of fungi and the apices of the haustoria of intercellular fungi must penetrate through the cell-walls of their host, either of the epidermis, or the membranes of other cells, consisting of cellulose alone, or in some state of lignification.^ The membranes may Ije simply pricked, as by a fine needle, so that the opening, because of the elasticity of the cellulose, closes up again after the perforating hypha has died. This is the case with many Ureclineae. In such cases the hypha is constricted in passing through the cell-wall and swells out again in the free cell-cavity. Frequently, as in the case of Ferono- sjjora densa, the haustorium will only cause a depression in the membrane of the cell without penetrating it. In addition to purely mechanical perforation of the mem- brane, the effect of the hyphae may also be a chemical one, so that the wall is dissolved and the holes produced remain long after the hyphae which made them have disappeared. This solvent effect is probably always present in cases where per- foration of lignified membranes takes place. It is a constant 'De Bary. Botan. Zeitumj, 1886. - De Bary. Biology and Morphology of the Fniu/i. English Edition. H. M. Ward. " On a lily-disease," Annals of Botany, 1888. Miyoshi. " Die Durclibohrung v. Membranen durch Pilze." 'Prlii'/shtim's Jahrbuch, Vol. 28, 1895. EFFE(JT OF PARASITIC FUNGI ON THE (JELL-WALL. 37 accompaniment of the attacks of wood-destroying fungi on the woody parts of trees and shrubs. Besides actual perforation of the lignified membranes of their host, the hyphae of many of the Polyporeae and Agaricini exert a solvent effect on the walls, which extends over a considerable area, and is evidently due to the excretion of some ferment. The dissolution of the walls takes place, moreover, in a way so characteristic for each species of fungus that they can be determined by it alone. From this it must be deduced that each wood-destroying fungus excretes a ferment peculiar to itself, which causes a character- istic dissolution of the host. Our present sources of informa- tion on these points are the very valuable investigations of I'rofessor Eobert Hartig of Munich.^ Some of his results will repay our careful consideration, but we must preface briefly some facts regarding the process of lignification and the forma- tion of heart-wood in our forest-trees. The elements of the wood of dicotyledonous trees and woody plants are derived from the cambium ; their walls consist at first of pure cellulose, and when lignification takes place the so-called incrusting substances are laid down in the thickened cellulose wall, particularly coniferin, vanillin, wood-gum, tannin, etc. ; or as they may be collectively called, lignin. The cellulose membrane itself is coloured lilac with chlor-zinc-iodine ; when lignified it no longer shows this reaction, but has others peculiar to itself, the best known being red coloration on treatment with phloroglucin and hydrochloric acid, or yellow coloration with aniline sulphate ; chlor-zinc-iodine colours lignified tissues brownish-yellow. Copper-ammonium-hydrate dissolves cellulose but not wood.2 If the incrusting substances be removed from the lignified membranes by treatment with Schulze's solution, caustic soda, or other solvent, the cellulose remains and reacts as such. In the process of conversion of allnirnum into dura- ' The most important of these works are : Die ZeDietzuiKjHi'rHcheinunijai d. Ilohts d. Nad(dhOlztr u. d. Eicht. With 21 coloured plates. Springer, Berlin, 1878. Der crhtt Hamnchii-amm, Merulius lacfa-ymans, 1885. Wichtiije Krankheitcn. d. Waldbmime, 1874. Lehrbnch d. Buumkrankheilen, I. and II. Edition, 1882 and 1889. English translation of II. Edit, by Prof. W. Somerville. Lekrhmh d. Anatomie %t. Physiolorjie d. Pjianztn, 1891. - For further reactions see : Zimmermann. Die hotani-sche Microtechnik. 1892. .Strasburger. Das botaimche Praktikum, 1887. English Edition, 1889. 38 REACTION OK HOST TO PARASITIC ATTACK. meii other substances make their appearance in the lignitied walls, chiefly tinctorial phlobaphenes. The walls of the wood-elements are, however, not ligniHed to the same extent. The primary layer of the wall is, as a rule, lignified most and contains but little cellulose. In con- sequence, on treatment with lignin-solvents, it becomes first dissolved while the secondary and tertiary membranes, although their lignin is also partially dissolved out, remain behind as a distinct framework of cellulose. With longer treatment destruc- tion of the tissue proceeds till only the pure cellulose membranes of the isolated cells remain. The ferments of many fungi act in this way ; for example Trametes inni, as shown in Fig. 1 2 ; at a the wall is in its normal condition, showing a primary Fir,. 12. —Section of tracheides of pine-wood in process of dissolutin ferment of Trametes iiini. l^"- (After R. Hartig.) wall and two striated secondary membranes ; at h the fungus- ferment has caused a splitting of the primary wall, which formerly appeared as a single layer, and the elements are separating from each other ; the " filling-material " of the inter- cellular spaces (under c), and the ring of lime surrounding the cavity of the pit d, remain for a longer time ; the right wall of the cell h consists only of cellulose, (as indicated by the striation being no longer shown, although still present) ; in the cell (' the primary wall has disappeared, and the secondar}' and tertiary membranes thin off towards / in which only the ash constituents remain as fine granules, better seen in Fig. 13. In contrast to the lignin-dissolving fungi, there are those which dissolve cellulose. When wood is treated with sulphuric EFFECT OF PARASITIC FUNGI ON THE CELL-WALL. 3^ acid the cellulose is dissolved out, and the primary wall remains almost intact, while the secondary after swelling is converted into sugar and gum. Certain fungi {e.g. Polyporus voporarins, P. Schweinitzii and P. snlphurem), act in the same manner, first dissolving out and consuming the cellulose before attacking the wood-gum. When wood is destroyed by fungi of this Fio. 13.— Tracheid of Finns sylcestris destroyed by Tmmetes jiini. The primary cell-Wall is completely dissolved from below upwards to n, a ; b, secondary and tertiary layers of the walls consisting in the under portion of cellulose only, in wliich granules of chalk are recognizable ; c, fungus-hyphae boring through the walls, leaving holes d and e. (After R. Hartig.) Fi(i. 14. — Tracheid of Pinu-t destroyed by Poh/poms Schweinitzii. The cellulose has been extracted, and the wall consists only of wood-gum. The fissures are a result of drying-up, but they do not extend into the primary wall a, h. Crossing of the fissures takes place at the bordered pits c, and at the bore-holes d and e ; /, simple fissures. (After R. Hartig.) kind, the primary wall, containing but little cellulose, is hardly affected, and the secondary meml;)ranes shrink together, so that numerous fissures are produced running in a spiral direction, corresponding with that of the stratification (Figs. 13 and 14.) The tertiary membrane varies in its nature ; it may consist of pure cellulose or be more or less lignified, or even cuticularized. In the wood-fibres of some plants {Cytisus, Htimulus,) this 40 REACTION OF HOST TO PARASITIC ATTACK. layer becomes normally loosened from the other membranes, and appears as a separate tube in the cavity of the fibre. Variations of this kind in the structure of the wood must of €ourse influence the action of the attacking fungus. The decay may be a local one, as with Trametcs ^Ji?i<', T. radicipcrda, TJiclcjjhora jurdix, which cause destruction of isolated spots only and produce holes here and there throughout the wood. On the other hand, the wood may be uniformly converted into a discoloured decayed mass. The walls may be simply pierced by little holes corresponding to the perforating hypha, or large portions of them may be more or less completely dissolved away, and either the cellulose or lignin remain behind as a skeleton. Hartig gives an interesting case which accompanies dry-rot {Merulius lacrymans)-. the mycelium adherent to the cell-walls dissolves out the lime granules included in the mem- branes by the excretion of some fluid containing carbonic (or other weak) acid, in mucli the same way as roots corrode limestone. The dissolution of starch in wood has already been considered. In conclusion should be mentioned Hartig's observation that normal spruce wood, on treatment with ferric chloride, the reagent for tannin, gives no coloration, such as is given by the same wood when destroyed by dry-rot. § 8. EFFECTS OF PARASITIC FUNGI ON THE ANATOMICAL STRUCTURE OF THEIR HOSTS. Effects of this kind can only be looked for where mor- phological changes have resulted from the presence of parasitic fungi, particularly in the case of hypertrophied organs. Wakker^ was the first to collect recorded evidence of anatomical changes due to hypertrophy ; he added to these by his own investi- irations, and classified the results. We shall therefore in this division depend chiefly on his publications. Enlargement of host-cells is one of the most frequent pheno- mena accompanying attacks of parasitic fungi. It may take place with both intracellular and extracellular parasites. A single cell hypertrophied in this way is the simplest possible form of a "fungus-gall" (see p. 25). Examples of nVakker, Priwj.sham's Jahrhnrh, 1892. EFFECTS OF PARASITIC FUNGI ON TISSUES OF HOST. 41 simple galls of this kind are cells of Pilohnhis Klcinii inhabited by Pleotrachelus fulgens, cells of turnip infested by Flasmodio- phora, or of dandelion with Synchytrium. Cell-enlargement resulting from the influence of extracellular parasites is most distinctly seen in those algal cells, which form lichens with the hyphae of certain fungi. Thus according to Stahl, the algal cells of the lichen Endocaiyon pusillum Ijecome enlarged six-fold. Cell-enlargement accompanies all hypertrophy of plant organs, whether the parasite lives purely intercellular, or has haustoria. At the same time one generally finds a disappearance of the intercellular spaces present in the normal tissues ; in some special cases, however, these may become more numerous and larger. Cell-enlargement, accompanied by disappearance of normal intercellular spaces and chlorophyll, are shown by Woronin's illustrations to be very marked in the galls on cow- berry, due to Exohasidiiim vaccinii. Cell-enlargement is also frequent in cases of hypertrophy due to Exoasceae ; thus in Taphrina aurea, although the mycelium is only subcuticular or penetrates but slightly into the epidermal layer, yet the cells are much enlarged and their walls are strikingly thickened (Fig. 63). Smith ^ found that when leaves became thickened in consequence of attacks of certain species of Taphrina, their cells became larger and rounder, so that the large intercellular spaces of the spongy parenchyma disappeared and the char- acteristic appearance of that tissue was lost. The epidermis, as has already been indicated, is influenced by fungi which live between the cuticle and cell- wall, as well as by epiphytic fungi, whose haustoria penetrate it. The epidermis is, however, more frequently destroyed by endophytes, which rupture it in forming their reproductive organs. Some of tliese produce their sporocarps inside the epidermal cells, and, as they enlarge, cause detachment of the outer walls of the cells from the remainder, to form for a time a covering which is ultimately ruptured as the sporocarps attain maturity. Where the fungi live under the cuticle {e.g. the Exoasceae), this alone is ruptured when the asci are formed. The repro- ' William fi. Smith. " Untersuchiing d. Morphologic u. Anatomic d. (lurch Exoasceen vcrursachten Deformatioiien. " Inaiig. Dissertation, Munich, 1894; also, Forstiich-naturivisa. Zeit^chrift, 1894. 42 KKAt rioN OF HOST TO I'AUASITK' ATTACK. duflive luyceliuiii of the t'ollowin-- forms also grows only under the cuticle: lihytisma andruma/ac, the spermogonial niyeeliuni of Pinrinia annnonc.% Phragmidhm, and other Uredineae. In many cases of hypertrophy the epidermal cells become enlarged in a radial direction, and this, as in Tcq)hrina cmrea, may be accompanied by considerable thickening of the walls. In other cases, like that i)roduced by Si/ncJn/frium, the epidermal cells may become gelatinous. The cork becomes abnormally increased in many examples of hypertrophy. Thus in witches' broom of alder due to Exoascus rpiphjilhis a phelloderm is formed, while on normal twigs phelleni alone is produced. Cork is found in juniper needles with Gijmnoqxrmngiinnjunipcrimim, though never in the normal needles. On the other hand, cork-formation is suppressed in twigs of hawthorn, deformed by Rocstelia lacerata. The so-called "wound- cork" is constantly associated with attacks of parasitic fungi; it separates diseased portions of rind and bast from sound, forms sheaths round Ijundles of sclerenchyma, and permeates the medullary rays. Collenchyma was found by Wakker to be absent in all cases of hypertKjphy of parts of plants where it is normally present ; for example, in stems and petioles of cowberry attacked by Ki:uh((si(hinu, stems of buckthorn with Aecidinm rhamni, of Cmtorfjus with RoeMclia lacerata, of nettle with Aecidinm nrticae, and of Sa)if/uisorhia with Xenodochvs carhonarius. On stalks of Umbelliferae with pustules of Protomyces, I found, where the collenchyma region was involved, that that tissue was not ileveloped (Fig. 46). In all cases of hypertropliy, parenchyma plays an important part. ]\Iost abnormal outgrowths result from multiplication and enlargement of the cells of the parenchyma, the formation of mechanical tissues being more or less suppressed. Thus the gigantic examples of hypertrophy exhibited by turnips infested by PlasvnxJvtphora, consist almost exclusively of parenchyma. Thickening of stems or branches is generally due to increase of the rind-parenchyma, as in l»uckthorn under influence of Arridiinn rJiainni, hawthorn with (ri/vDuisjMnuiirjium clavariae- foTvir, in most witches' brooms, and in many other cases. In EFFECTS OF PARASITIC FUNGI ON TISSUES OF HOST. 43 che witches' brooms due to Accidiuin (iatinam, the pith appears enlarged as the result of increase of the medullary parenchyma. In diseased leaves, palisade parenchyma can frequently no longer be distinguished from spongy, and only irregular polygonal cells are formed. As examples may be given needles of fir with Aecidimn abietinum, and leaves with galls due to Exoasceae. Finally, there may be a marked increase of wood-pareiichyma, both of medullary rays and the wood proper; this is especially well marked in Junipcrus communis affected by Ghpnnosporangiuvi juniperinum} where in consequence of an enormous increase of the parenchyma of rind and medullary rays, the tracheidal regions become separated by broad wxdge-shaped rays, and at the same time they are peripherally intersected by bands of paren- chymatous tissue resulting from increased development of the wood-parenchyma (Fig. 220, etc.). The Sclerenchyma is generally suppressed where hypertropiiy occurs. Examples mentioned by Wakker are stems of cowberry with Exohasidium, of hawthorn with Gymnosjjoraiigmm, of SanguisorUa with Xenodochvs, and alder catkin-scales with Exoascus. On the other hand, sclerenchyma is developed in stems of Cirsium as a result of Puccinia si/airolens, whereas normally it is absent. The secondary vessels of the wood frequently remain irregular, and with imperfectly absorbed partition-walls. According to Wakker, this is the case in Vaceinium with Exohasidivm, Crataegus with Bocstelia, and Rhamnus with Aecidhnn. Suppression of interfascicular cambium was observed by Wakker in buckthorn and nettle with their respective Aecidium parasites. Prolonged activity of the same tissue he found in Sisymhriuin with Cystoinis. Arrest of lignification was found by Wakker in medullary rays of Crataegus with Boestelia, and in deformed scales of alder catkins affected by Exoascus. We have already considered increased growth in length and thickness in connection with hypertrophy. It need only be added that increased thickness of woody plants may be due to increase of the rind, the bast, the ]nth, or medullary rays, and not • P. Wornle. " .Anatomische Untersuchung d. dmch Gymiiospoiangium-Arten hervorgerufenen Missbildungen." Iiiaug. Diss., Miinchen, 1894; .also, ForstUch- iia/m-irlss. Zeifxchrif/, 1894. 44 REACTION OF HOST TO PARASITIC ATTACK. to increase in the actual wood elements. Tliis is the case in twigs of silver fir witches' brooms, in young swellings of juniper attacked by Gjjninosporcuigiu.m, and in the thickened twigs of Alhizzia resulting from Uromyces Tcpperianus (Fig. 181). There may be, however, a distinctly increased growth of the wood. Thus, with attacks of Gymnosporangimn frequenting juniper, especially G. sahinae, there is often a marked thickening of branches due to increase in the xylem-elements. Again, one finds cankers due to Aecidinm datinum, accompanied by stem- swellings with a diameter twice or three times that of the normal, and in which the bark and bast form but a thin layer in proportion to the part made up by the wood. Exceptionally striking are the gigantic woody knots formed on the Japanese Finns dcimflora, and P. fT""^. Thunhcrgii affected by Peri- dcrmium gigantcvm (Fig. 15).^ -?' ^XT', ^ >' f'^ Wakker found that niu- '*'^^-. rJ*^,0,.^H> eilage canals of Bhamivm J^"^^ ,"' ^ Frangnia affected by Acci- ^'^■,<^ .^ diam were not so well ?' ^ developed as in normal twigs. liesin-canals are often irregularly formed and ab- Fio. 15.— Wood-swelling on Pi)iits(;e/is(lrt()/((, attacked nomiallv multiplied ill COU- at this place by Peridermiuni (jiganteum. J natural size. "^ *■ (V. Tubeuf phot.) sequeiice of parasitcs. The (On Puiiis r/iitH'^crffustiUlargerexaraples may occur.) ^ ^ resin-canals of the spruce were found by Hartig to be so numerous in plants attacked by Agaricus melleus that an abnormal quantity of resin is produced in the wood, and flows from the diseased roots ; hence has arisen the name " resin-glut " or " resin-flux " by which the disease has long been known. A particularly noticeable flux of resin takes place from pine-bark in presence of Pcridermium pi/ii ; the mycelium grows in the medullary rays and resin- canals, causing an excretion of resin from all living parenchyma in the wood, so that both • bast and wood become completely impregnated with resin, and thin sections of wood transmit a rose-coloured lifdit. I CHAPTER III. RELATION OF PARASITE TO SUBSTRATUM. § 9. EFFECT OF THE SUBSTRATUM ON THE DEVELOPMENT OF THE PARASITE. A NUMBER of parasitic fungi live only on one species of host. For example Sderotmia haccarum on Vaccinium Myrtilhi.a, ChrysomyoM abietis on Ficea excelsa, Triphragmium ulmariae on Spiraea ulmaria, Hysterium nervisequium on Abies pectinata, Rhyiisma andromf.dae on Andromeda polifolia. De Bary^ proposed for cases like this the term monoxeny, while to cases in which a parasite frequents several different species of host he gave the name polyxeny, or more particularly, dixeny, trixeny, etc. As examples of polyxeny may be mentioned lihytisma salicinvmi found on all species of willow, and Bhytisma acerinvm on the genus Acer. Other parasites attack not only different species of some genus, but also different genera ; thus, Puccinia graminis occurs on various cereals and grasses, Pliytoplitliora omninora on many different plants, FhyUactinia suffulta on leaves of Corylus, Fag us, and many other trees ; Clavicejps piirpurea on a large number of cereals and grasses, Cystopus candidus on many Cruciferae, and Neetria cinncdwrina on all kinds of broad-leaved trees. Monoxeny and polyxeny must be carefully distinguished from the autoecism and heteroecism of the Uredineae. Many species of this group go through their whole life-history, and produce all their forms of spore on the same host, others, however, pro- duce some forms of spore — spermatia and aecidiospores — on one host, and the remainder — uredospores and teleutospores — on ^ Botanische ZtUuiui, 1867, p. 264. 46 RELATION OF PARASITE TO SUBSTRATUM. another host. Such heteroecious parasites may be, however, also luonoxeiious ; for example, Mclam^ysora Goeppcrtiana has its teleiitospore-form only on the cowberry, its aecidium-form only on the silver tir. On the otlier hand, ChnjHomijxa rkododendri frequents several species of Ehododendron, while the aecidia occur only on Picca cxcelsa ; Cronartium asclcjjicidcum comes on both Gentiana and Cynanchum, the aecidial stage only on Finns sylvestris. With Gymnosporanginm clavariacforme this condition is reversed, the teleutospore-form occurs only on Junipcrus co)anumis, the aecidial on various species of Cratacyns and other genera. The effect of various substrata on the development of any fungus may Ije most conveniently investigated : {a) on facul- tative parasites and saprophytes, {h) on polyxenous species of fungi, (c) in cases where the fungus inhabits essentially different organs or tissues of the same host. The most obvious effect of the substratum is presented during the germination of spores. The spores of most parasites ger- minate in water. Those of certain smut-fungi, especially in tlie fresh condition, will not germinate at all, or only to a very limited extent in water, whereas they will do so immediately and unanimously on being offered a nutritive solution. Tilktia, a genus of Ustilagineae, behaves, however, in (piite the reverse way, it germinates only in water, and refuses to do so in nutritive solutions. Hartig found that the spores of dry-rot {Mcrulim) would neither germinate in water nor in tlie usual nutritive solutions, but that they did so at once on adding alkalies to the water, such as those supplied by addition of urine. Very characteristic is the behaviour of these spores, which only germinate in contact with their host-plants, like many Chytridieae ^ (Synchytrium), as well as Complctoria and Protomyccsr Others again send out germ-tubes which remain small and soon die away if an immediate opportunity of penetration into a host is not presented. De Bary states this to be the case with swarm-spores of Cystopas, Peronospora nivea, Erysipheae, etc. Amongst the Uredineae, the germ-tubes are short-lived ; they will penetrate into almost any 1 De Bary, Morphology and Biology of the Fuiigi, cliap. vii. - An exactly parallel case is presented by the seed of Orobancheae, wliich germinate only in contact with the roots of their host (Koch's "Orobanchen," Heidelberg, 1887). EFFECT OF SUBSTRATUM ON DEVELOPMENT OF PARASITE. -17 host, but soon die off, if it be not a suitable one. De Bary also observed a germ-tube of Peronospora pygmam, which IVeciuents Aiiemonr, making its way into Hammcuhis Ficaria, l)ut soon to die. Germinating spores of Cystopus canduhts will enter the storaata on leaves of any of their host-plants, especially Capsella, but will only develop further if they are successful in penetrating into the cotyledons. Variation in the substratum produces very great difference in the formation of the reproductive organs. Thus many Ustila- gineae produce conidia by continuous sprouting only when cultivated in nutritive solutions, while their resting-spores are developed only from a mycelium which inhabits the reproductive organs of their host; this is the case with Ustilago caricis, U. anthcarum, and U. tritici. In others the spores are found in all parts of the tlower, and even in the inHorescence, as in Ustilayo criwnta and If. tragopogonis, while in Ustilago maydis spores are also produced in leaves and stems. The various parts of the same plant behave very differently in this respect. The Ustilagineae just considered reproduce them- selves only on certain organs of their host, although the mycelium is also present in other organs. Other fungi behaving similarly are UjncJdoe tyjjhina which produces its perithecia only on the surface of the sheath of one of the leaves just below the inflorescence ; Aecidimn datirmm develops its aecidia only on the needles of the witches' broom; Aecidium cnphorbiac has its aecidia only on the leaves of its host ; Ecoascus p)rnni has asci only on the fruit ; Calyptospora produces teleutospores in the epidermal cells of the stem, never of the leaves ; and so on in many other cases. The formation of oogonia of Cystopus exhibits a striking vari- ation according to the host-plant. Cystopus candidus on Capsdla produces conidia alone, never oogonia ; yet the latter are plenti- fully developed in flowers of Brassica, being confined, liowever, to the flowers, while conidia are produced in all parts. Cystopus hliti forms conidia only in the leaves, and oogonia only in the stems of Amaranthus hlitum} The mycelium of many other fungi can only grcjw in certain organs, while germ-tubes from the spores are only able to pene- trate into certain parts of the host. Thus, E.coascus cdni incanae M3e Bary, Morphology and Bio/or/y of the Fun;//, English Edition, j). lid]. 48 RELATION OF PARASITE TO .SUBSTRATl'M. has a luyccliuin only in catkin- scales ; Rwascus prviii, however, hibernates in the twigs, and forms reproductive organs only in the walls of the ovary ; Aecidium strobilinum grows only on the cone-scales of spruce; Claviccj)^ frequents only the young ovaries of cereals and grasses; and so on, other fungi inliahit only leaf, stem, root, or flower. In this connection points of considerabk' interest are presented b,y the behaviour of many Uredineae hitherto little investi- gated. As was pointed out by De Bary, the germ-tubes produced from both uredospores and aecidiospores (in Fuccinia (Uanthi those from sporidia also), penetrate into the stomata of any phanerogamous plant. If, however, that should not be a host-plant of the fungus in question, then the germ-tubes die away in the stomatal air-cavity. If tlie host suits the fungus only in a Ihnited degree, then no hypertrophy will result, and the latter will attain only to the formation of spermo- gonia. Let the host, however, be the one best suited to the fungus, then hypertrophy will result and aecidia be developed. Very conclusive evidence of this interesting condition has been furnished by numerous experiments which I have carried out with spores of G^ymnosiJoranyium} If one infects Cratacgvs Oxyacantha with G. davariacformc, very marked stem-hypertrophy results, even by the time the spermogonia have made their appearance ; there is also considerable swelling of leaves and slif'ht enlargement of cotyledons, while aecidia are produced in numbers everywhere. When the same fungus is used to infect Pyrus Aucuparia, no yellow spots or malformation of any kind results, and spermogonia, hardly visible with a lens, are formed only here and there. A similar infection on Pyrus latifolia {P. Aria X torminaUs) results in a crop of badly developed aecidia. If quince be infected, then without any hypertrophy whatever, little red spots bearing numerous spermogonia are formed on the leaves, but the development of the fungus ceases there; on the death of the quince leaves, the chlorophyll is retained in the immediate neighbourhood of the spermogonial spots, so that they remain for some time as green islands on the yellow leaf. E. Hartig's infections with Mdam'paora trcmvlae also led to varied results ; on Pinus there ensued a distinct disease of the cortex {Cacoma jmiitin-qnum), 1 V. Tul)euf, Centra/Matt f, Bacteriologie n. ParasitenJcnndc, 1S91. EFFECT OF SUBSTRATUM ON DEVELOPMENT OF PARASITE. 49 while on Larix only little cushions appeared on the needles (Caeoma laricis). These variations in the effect of the substratum on the development and reproduction of the parasites assist us to understand the well-known resistance of certain varieties and species against epidemic diseases, which are sweeping off their near allies. Thus, we know that some varieties of cereals suffer from attacks of rust-fungi more than others grown under like conditions. Similarly amongst the varieties of vine some are known to be more sensitive to disease than others. These points will be more fully discussed in a subsequent chapter. CHAPTER IV. NATURAL AND ARTIFICIAL INFECTION. § 10. In artificial infection we have a safe mode of distinguishing whether a fungus is parasitic or not ; in other words, whether it is capable of penetrating into the organs of living plants. This method of investigation should always be resorted to in determining the cause of disease, more especially if mycelium or sporocarps of several fungi are present on the diseased material simultaneously. For it not unfrequently happens that the disease has made so much progress as to make it quite impossible to determine whether or not any fungi present on the dead remains are really the cause of disease. In many cases where one finds a mycelium in living parts, it has disappeared, and only sporocarps remain in portions already killed. Injuries due to insects frequently accompany fungi on a diseased plant, so that it is extremely difficult to say which was the primary cause of the damage, and artificial infection must be resorted to. So also with injuries from some external source like drought, heat, cold, moisture, and mechanical causes. Fungi appear so soon after hurtful agents like these, that it becomes doubtful whether they are the cause of the death of the host, or the result of it. Minute observations in situ of all tlie circumstances connected with the attack, combined with examination of numerous speci- mens and comparison with neighbouring plants, enable one, after some experience, to say with a fair degree of certainty, whetlier the disease in question is of fungoid origin or not. NATURAL AND ARTIFICIAL INFECTION. 51 The exact proof, however, is best obtained by means of experi- mental infection. With many parasites the sporocarps are normally developed saprophytically on a dead substratum, so that if parasitism be suspected it can only be proved by infection. Thus the perithecia of Ncctria cinnaharina develop only after the death of the plant-organ, which the fungus attacked when alive. The more complex reproductive organs of many fungi are developed only on dead remains of the host, while on living or dying parts one finds various forms of conidia of doubtful relation- ship. In many cases it has been possible, by means of artificial culture alone, or combined with artificial infection, to prove various forms of reproductive organs to be stages in the life of the same fungus. When a group of fungi contains both saprophytes and parasites, it is often necessary to determine whether some species is para- sitic or purely saprophytic. This is particularly the case with the groups of Pyrenomycetes, Discomycetes, Hymenomycetes, several groups of the lower Fungi, the Bacteria, and Myxomycetes. It is unnecessary, however, with the Uredineae, Ustilagineae, Per- onosporeae, Exoasceae, and other groups known to contain parasites exclusively. Put even in these last-mentioned groups experimental in- fection is necessary for obtaining information on other points. The reproductive organs of Uredineae cannot be reared in artificial solutions, so that their cultivation must be carried out on the living host-plant. In this way alone can we ascertain the relationship of uredospores, teleutospores, and aecidial-forms, where any doubt occurs as to their belonging to the same species. Infection becomes particularly valuable when one has to investigate heteroecious Uredineae, whose various forms of reproductive organs inhabit several host-plants. Thus it was by means of infection that De Bary discovered the connection of Aecidiiim berhcridis on the barberry, and Pitccinia graminis on cereals ; likewise Hartig, the relationship of Melampsora Goep- pertiana on cowberry with Aecidimn columnare on needles of silver fir. There still remain many aecidia, teleutospores, and uredospores, whose related forms have not yet been found. Infections are also necessary to determine the species of a fungus. It has been found, for example, that Gymnosporanfjiiim 52 NATURAL AND ARTIFICIAL INFECTION. confusum and G. sahinac may, in their aecidial stage, be dis- tingnished as two species inhabiting distinct hosts — Crataegns and Pi/rus respectively — whereas, in their teleutospore stage on juniper, they scarcely vary. In infection we have an important aid in determining the host-plants of the various forms of heteroecious fungi, and in this way it has been found that the same fungus behaves differently according to the host-plant on which it is present. Thus, in the genus Gymnosporangium, I have found that a certain species had well-developed aecidia on one plant, poorly developed ones on another, while on a third only spermo- gonia appeared. Similarly, in that case already mentioned, Hartig found the Mdnin2)sora of the aspen to produce on the pine a disease of the cortex, accompanied by marked deformation, while on the larch the symptoms were mere inconsi)icuous aecidia on the needles. Amongst the Ustilagineae, experimental infection is necessary to determine whether the natural infection of host-plants results from germinating spores (chlamydospores), or from germinating conidia (sporidia). Kiihn was able by this means to demonstrate exactly that the spores of Ustilagineae produced germ-tubes capable of direct infection. Brefeld succeeded in observing the penetration of germinating sporidia into a host-plant. In this way he proved, amongst other facts, that maize may be attacked by Udilago maydis on any young part ; also, that the mycelium remained local. Oats, on the other hand, could only be infected by Ustilago avenae at the neck of the young seedling, and the mycelium extended through the plant till it reached the inflor- escence, where the spores are formed. In the case of the Exoasceae, two points were cleared by the aid of artificial infection — the penetration of spores into leaves of host-plants, and the production of witches' brooms. Sadebeck,^ by means of infections of Exoascus epiphyllus on Alnus incana, has produced witches' brooms artificially, thus proving that these malformations really originated from the mycelium of Exoascus. It is by infection-experiments that one determines into which part of a host the germ-tubes penetrate, whether into leaf, flower, fruit, stem, or root, and also whether it passes through the epidermis, or between two adjacent epidermal cells, or through ^ Kritisclie. Untersuchunrjen iiher d. dvrch Taj^irina hervorgehrachteii Bauvi- krankkeiten, 1890. NATURAL AND ARTIFICIAL INFECTION. 53 the stomata. Also, whether the germ-tube formed from a germinating spore penetrates direct, or if, as shown by De Bary for Schrotinia, a mycelium vigorous enough to penetrate must first be developed saprophytically. In this coiniec'tion De Bary ^ states that tlie germ-tubes fi-om all aeeidio- spores and uredospores only penetrate by stomata, and thence extend through the intercellular spaces. Entry through the stomata has also been observed on the germ-tubes from sporidia of Leptopuccinia dianthi, and from spores of Entyloma. On the other hand, germ-tubes from the spores of teleutospores, from spores of Peronosporeae, Ustilagineae, tSderotinia, Polystigma, Pro- tomyces, and Synchytrium effect an entrance through the outer cell-walls into the epidermal cells or stomatal guard-cells. De Bary also describes the peculiar behaviour of zoospores of Cystopus and Feronospora umhelliferarum, which, if they come to rest near a stoma, germinate, and the germ-tube enters therein, whereas one developed in water soon dies. Certain fungi penetrate sometimes tlu'ough the niembi\ane, sometimes by a stoma, e.g. — Phytophthora infestans, Feronospora parasitica, Exohasidium vaccinii. In the case of Fhytophthora omnivora, Hartig found that the germ-tubes from the zoospores crej^t along the sui'face of the leaf till they reached a place where two epidermal cells adjoined ; there they entered, and only rarely grow into the epidermal cells. The germ-tubes of Frotomyces macro- .'tporus and Tuhurcinia trientalis enter their hosts in the same way. From experiments, one is able to determine the conditions favourable, or otherwise, to infection by parasitic fungi; to ascertain the influence of temperature, air-moisture, water-content of the host, hairiness of the leaves, and the effect of resin or other excretions as protections to wounds. For example, it was in this way that Hartig found Saliv pulchra {pruinosa x d(rphnoidcs) to be a hybrid which, on account of its hairy leaves, is more resistant to Mdarivpsora than Salix pruinosa} ]\Iuch investiga- tion remains yet to be done in this direction to ascertain what varieties or species of cultivated plants are likely to be least liable to attack by epidemic diseases.'^ The methods used in carrying out artificial infection are leased on the observation of cases of natural infection. Most frequently infection is performed by means of spores, less often with mycelium. The spores of lower forms of fungi are generally distributed by means of water, especially in dew or rain. Zoospores are ^ Morphology and Biology of the Fmigi, English Edition, pp. 361-362. -Hartig, Dweases of Trees, English Edition, 1894, p. 171. ^See Chapter v. on "Disposition." 54 NATUKAL AND ARTIFICIAL INFECTION. completely adapted for distribution in water. Amongst the higher fungi, spore-distribution almost always takes place by means of wind. Insects as agents are rare, although one does occa- sionally find special adaptations intended to secure their visits. The spores of many fungi are forcibly ejected from the sporo- carps, asci, or sporangia ; some of the many arrangements which ensure this will be given in the special part of this book, others will be found in the works of Zopf,^ and De Bary.- Ludwig, in his text-book,^ points out that the spores of many Ustila- gineae frequenting entomophilous flowers, are provided with ridges and spines, which are probably an adaptation to their transportation by insects; smooth-coated spores are more common on leaves, stems, and organs other than the flower, and are evidently distributed by the agency of wind. T\\v mode of distribution and infection is quite apparent in many fungi. Thus in the oat-smut {Ustilago axenae), the diseased ears in a field rise above the sound, so that the light dusty spores are shaken out in clouds by the slightest wind ; they hibernate on the earth or on straw, and germinate in spring to infect the oat-seedlings at the base of the stem. Equally simple is the distribution of spores and conidia from one plant to another by wind during summer. Good examples of this mode are the conidia of the Erysipheae, and the aecidiospores and uredospores of the Uredineae. Thus, the yellow spores of Clirysomyoxi rliododcndri, when the aecidia are present in very large numbers on the needles of spruce, may cause the phenomenon known as " sulphur-rain." It is well known that this is generally due to the yellow pollen of conifers caught and carried to the ground in showers of rain, but E. Hartig describes a case observed by him near Achen-see (Tyrol), where objects were covered by a yellow dust, consisting exclusively of spores of Chrysomyxa. Spores of this kind are capable of transport to very great distances, so that heteroecious species can still keep up their connection even though by no means near each other. Aecidiospores of all kinds are distributed more Ijy wind than by insects. In rare cases, however, the aecidia have a sweet floral ^Zopf, Die Pih.e, 1890, p. .349. = De Bary, Morpholoi),i\^ Jahrhitrl,, ISSS. Temme, Liindinrlhsrhafll . Jithrl,iirh, 1,SS5. Frank, Die h'nnditn/tn d. Pjlair.m, 1894, p. 153. PREVENTIVE AND COMBATIVE MEASURP:S. 77 wound must remain open till completion of occlusion." If we followed this view, then numerous wounds would be left freely open as entrances for wound-parasites, and serious loss would result. It is just the numerous smaller wounds {e.g. those produced by hail), which are the principal places of infection for species of Nectria, Cucurbitaria, Hymenomycctes., etc., in fact, they form very convenient places whence a tree may be easily infected artificially. The following points in regard to treatment of branches may be conveniently summarized here. Trees in closed plantations are naturally stripped of their branches by these dying in con- sequence of deficient illumination ; they then break off, and the short stumps are soon occluded or grown over. During this process there is always a risk of infection by fungi, and " snag-pruning " ^ is employed to shorten the period of occlusion as much as possible. This at the same time prevents the in- clusion of long branch-stumps in the timber, and reduces the number of knots in sawn boards. Such dead snags or stumps are deficient in nutritive materials and very dry, so that they are less suited for the entrance of wound-fungi than wounds on the living branch. The usual process of forest-pruning is necessary to produce clean boles, to increase the illumination for undergrowth, or to utilize the branches so removed. In the operation, all branches should be cut of!' close to the shaft, no snags should be left, nor must injury be infiicted on neighbouring bark. The operation is best carried out in autumn or winter when the bark is most adherent to the wood, occlusion then begins with the renewal of vegetative activity in spring and is well advanced by the time the greatest dispersal of fungus-spores takes place. Infection by fungi will, however, be rendered quite impossible if wounds are immediately painted over with tar, or, in the case of smaller wounds on garden stock, with tree-wax ; these reagents, if applied in winter, will easily penetrate into the wood, and even replace the formation of protective wound-wood. Hartig says on this subject : ^ " tarring produces satisfactory results only when pruning has been done in late autumn or in winter, because it is only then that the tar is absorbed by the surface of the wound. It would appear that the absorption of tar is due partly to the diminished amount of water in the- 1 Trockeniistung. - Hartig, Dhtasta of Trees. English Edit. p. 258-59. 78 rUKVENTIVE AND COMBATIVE MEASURES. wood during autumn, and partly to the consequent negative pressure of air in the tree. When pruning is undertaken in spring or summer the tar altogether fails to enter the wood, and the thin superficial layer does not prevent the cut surface from drying later and forming fissures into which water and fungi may enter." From what has been said it follows that dicotyledonous trees may be best pruned in the months of October, November, and December — perhaps also in January and February, — and that a good coat of coal-tar should be at once applied to the wounds. Conifers should also be pruned in autumn and winter, for although the wounds resulting from removal of small branches with no heart-wood are soon protected by an excretion of resin, yet thicker branches with heart-wood, which secretes no resin, must be tarred over. Similar precautions are advisable to protect the stools of trees felled in order to produce coppice. Wounds are produced on fruit-trees by removal of branches, by pruning and grafting, and again during the fruit-harvest. Hail and wind are frequent sources of wounding. Gnawing of the bark by animals, such as mice and other rodents, may also occur. Red deer, by peeling off the bark, are a source of great damage in the forest. In this way spruce plantations may be so peeled, and in consequence so subject to red-rot that they have to be prematurely felled. The trees which suffer most are those like spruce, silver fir, Weymouth pine, and Douglas fir, which remain for a considerable time smooth-barked, whereas species with a rough bark are comparatively safe ; the latter can also cover up any wounded surface by means of an excretion of resin. Conifers suffer most from peeling, but the broad- leaved trees are not quite exempt. At certain seasons the deer rub the fur off the young antlers or knock off the old ; for this purpose they generally choose younger plants, which, in consequence of the injury, frequently dry up. Injury by deer is more serious in summer than in winter, because with the increased temperature and moisture the spores are able to convey infection quickly and easily. Injuries similar to peeling by deer are produced in gathering resin, and in the process of " testing " the timber of conifers. Both practices are, however, prohibited in well-managed forestry, and occur only as misdemeanours. Eesin-collecting of whatever PREVENTIVE AND COMBATIVE MEASURES. 79 kind, whether from spruce, larch, phie or the silver fir, necessi- tates removal of the bark, and probably cutting into the wood itself. The exuded resin and naked wood dry up in course of time and crack, thereby allowing the entrance of fungus-spores, which germinate in the fissures of the wood and lead to its destruction. The forests of spruce and fir in Bavaria furnish valuable wood suitable for the manufacture of violins and other musical instruments. Till recently the practice was first to split a test- piece from the standing tree to ascertain the cleavage of the stem. If the test did not split true, the tree was left standing and wounded ; such stems naturally were soon attacked by fungi (Polyporeae and Agaricini) and succumbed to some storm. The beech is frequently injured in a somewhat similar manner by the woodmen, who hew out large pieces of the stem to obtain material for wedges from the very tough occlusion-tissue which is afterwards formed. Stems so damaged soon fall a prey to Pohjporus fomcntarius. Wounds to the wood are also frequently produced during the felling of neighbouring trees, or as a result of storms, or by the action of woodpeckers, ants, and other enemies. In short, wounds are so common that the necessity of practical remedial measures for closing them as entrances for destructive parasites, must be at once evident. (2) Localities should be avoided which are known to pre- dispose certain plants to disease. Just as one avoids cultivating tender plants in cold situations, or planting our less hardy trees in places known to be liable to frost, so ought we to avoid the cultivation of plants in localities which will render them more than usually liable to infection by fungi. Thus the formation of spruce-nurseries at considerable elevations has had to be abandoned, because it was observed that they were there liable to complete destruction by Herpotrichia nigra. For similar reasons the hole-planting of spruce in elevated situations must be avoided. In moist localities nurseries of Douglas fir and other trees are in danger of attack from Botrytis; while close glass-houses and hot-beds are breeding-places for many parasites which would at once die away with good ventilation. (3) The neighbourhood of plants which are supplemental hosts of the same heteroecious fungus should also be avoided. (See also p. 74.) 80 PREVENTIVE AND COMBATIVE MEASURES. (4) The massing of numbers of the same species of plant together is dangerous, because it presents a favourable oppor- tunity for the rapid spread of epidemic diseases. On this account the smaller fields of small holdings tend to prevent any epidemic from assuming serious proportions. Still better is a system whore, as in Northern Italy, a few rows of vines alternate with narrow strips of Indian corn with gourds or melons on the ground below, and strips of grass or millet intervene here and there. Wherever similar plants must be cultivated in close neigh- bourhood over extensive areas, as in vine cultivation, any epidemic, which may obtain a hold, soon produces disastrous eftects. Our cultivated forest plants, when occupying extensive areas, are particularly open to attacks of certain fungus-diseases. Thus Pines from Hystcrium phiastri, Cacoma pinitorquum, and Pcridcrmium ^^mt ; pole-forests of pure spruce from Hysterium macrosporum, all plantations of conifers from Trametes radi- ciperda and Agaricus mclleiLS, the latter especially if preceded by beech forest, the stools and dead roots of which offer the Agaricus an opportunity for easy and abundant development. The prevention of many epidemic diseases is one of the advantages claimed by Gayer ^ in favour of natural regeneration and nuxed plantations. On exposed areas the prevailing strong winds facilitate distribution of many fungus-spores, while, at the same time, they introduce the supplemental hosts of of heteroecious fungi {e.g. aspen, ragwort, cowberry, etc.), which would be excluded from a closed permanent mixed forest natur- ally regenerated. Of course, we do not maintain that, under these conditions, diseases are entirely absent, because it is just on naturally-sown beech seedlings in closed forests that Phytoph- fJiora finds a habitat. Similarly TricJwsphaeria on silver fir, and other parasites, are in closed forest provided with that degree of atmospheric moisture which favours them. In fact, several parasitic fungi exhibit adaptations to such conditions. Diseases, speaking broadly, are less dangerous in mixed forest ; they never attain the same distribution, and they are more easily restricted where trees of different dispositions are grown together. Thus, the forests of Bavaria consist, in the lower elevations, of mixed beech, silver fir, and spruce : higher up ^ Gayer, Der Waldbau. PREVENTIVE AND COMBATIVE MEASURES. 81 the beech is omitted, and in the more elevated parts spruce alone is planted. The fir alone is attacked by Plumia ahictina Accidium datininn, Loi)hodcrmiu.m nervisequium, Trichosphaeria pdvasitica ; the spruce, on the other hand, has to itself Lophodermium macrosporum, Chrysomyxa ahietis, Hcrpotrichia nirjra, while both are subject in youth to Pcstalozzia Hartviii, and later to several wood-destroying fungi. The storing together of crops like apples, potatoes, onions, turnips, etc., should be carefully carried out. They should be handled as little as possible, and decaying individuals should be sought out, and destroyed when possible, to save the remainder. IV. Selection of hardy varieties. An important method for the protection of plants from disease, both from the preventive and remedial side, consists in the selection and cultivation of varieties and species of plants able to resist the attacks of parasitic fungi. It has already been mentioned that different varieties and species show different powers of resistance against enemies. As a further example, we have numerous American grape-vines which are not attacked by downy mildew {Plasmop)ara viticola), that dangerous enemy of the European vine of cultivation ( Vitis vinifcra). Some American vines {cjj. Viiis riparia) are proof against the phylloxera, the root-louse which attacks the roots of European vines and devastates the vineyards of the wine-producing countries ; while, on the other hand, othei- American vines are no more resistant than the European. In fact, it was the importation of those vines into Europe for experimental cultivation which brought us both pliylloxera and the downy mildew. The cultivation of sucli disease-proof species would ensure us immunity from the phylloxera, if it were not that the wine from these vines has neither the quality nor the fiavour possessed by the European. On this account tlie grafting of European vines on American stocks has been introduced, whereby the roots remain unattacked by the phylloxera, and the grapes are of the approved standard. Very good results have also been obtained from experiments in hybridization of American and European vines with the object of obtaining roots from the American parent, and grapes from F 82 PREVENTIVE AND COiMBATIVE MEASURES. the European. The long and patient experiments of Millardet ^ are the most conspicuous amongst many which, by means of grafting and hybridization, have aimed at obtaining disease-proof vines. Millardet, out of numerous hybrids raised by him, has succeeded at last in obtaining vines with roots proof against phylloxera, leaves resistant to attacks of downy mildew, and grapes which impart the esteemed flavour to the various old and well-known European wines. From these many ruined vineyards of southern France have been already re-stocked, and promise well. The results obtained from Eriksson's investigations on cereal- rusts are also worthy of notice.'-^ This investigator, after carrying on cultivations for a number of years, has found that there are varieties of wheat able to resist the more frequent forms of rust, and in no way endangered by them. By a similar method of investigation, varieties suitable for cultivation in the rust- infested districts of Australia have also been obtained. ' Millardet, " Notes sur les vignes americaines." 8er. iii. Mem de la sor. c/es -sciences de Bordecmx, 1891; Jottrn. cV agriculture pratique, 1892; Compt. rend., 1894; Zeitschrift f. Pflanzenhrankheiten, 1894, t^. 47, and 1895, p. 116. Esser, "Die Bekiimpfung parasit. Pflanzenkranklieiten," Samml. ivissenwh. Vortrcige; bj' Virchow n. Wattenbach, 1892. With Bibliography. -Eriksson. Zeitschy-ift f. Pflanzenkrankheiten, 1895, p. 80. CHAPTER VII. ECONOMIC LAIPOKTANCE OF DISEASES OF PLANTS. § 13. The economic importance of any plant-disease depends on its distribution, its intensity, and the vahie of the plants attacked. Of most consequence are those epidemic diseases of fungoid origin, which cause rapid death of their host, and spread with great rapidity over wide areas. Such, tlirough repeated attacks, may render the cultivation of certain plants impossible in a locality. Almost equal damage may result from those parasites, which, although they do not kill their host, yet destroy or prevent the development of that part for which we grow the plant. Amongst these are species which inhabit flowers or fruits, the wood-destroying fungi of forest-trees, and forms inimical to the foliage, roots, or tubers of plants •of economic value. As examples of parasitic fungi which bring about rapid death of their host, are the originators of many diseases of young plants. Phytophthora oriinivora may during a few days of damp weather completely kill out not only healthy beds of seedling beech or conifers in the nursery, but even the young plants hy which a forest is being naturally regenerated. Pcstalozzia Hartigii, a few years ago in the beech-forests in some districts of Bavaria, exterminated three-fourths of the naturally-sown plants from one to four years old. Hurjwtrichia nigra is capable of completely destroying the young spruce plantations, so important for the afforestration of bare slopes in mountainous districts, and it may attack with such violence nurseries established at great cost and labour that they have to be 84 ECONOMIC IMI'OHTANCK OF DISEASES OF PLANTS. abandunetl. AVliole gardens of roses have l)een devastated by Pn-onospurn sjxirsa, and nurseries of conifers have been exter- minated by Hi/sfrriiivi pinastri, or Afjaricvs inr/lais. Aniouiist the fungi, which attack the organs of older plants and cause serious losses to cultivators, are the following: the u-ell-known potato disease caused by Pkytophthora infcstans\ tlu' vint- diseases arising from Uncinu/a sjnralis, Flasmopara viticola, and Deviatophora nccatrix ; many diseases of conifers and other trees. As destroyers of the fruit alone may be mentioned the smut-fungi of the cereal crops. Other cases of injurious diseases, of more or less practical import, will be described in the special part of this book; at present we sliall only select a few estimates of the loss result- ing from them. In the forest of liischotfsreut in IJavaria — a magnificent one, containing spruce, fir, and beech — eighteen per cent, of the felled timber consisted of wood rendered useless by decay ; while fifty years ago the utilizing of the so-called fungus-sponges of Pob/porm fomcntarius in the same forest for manufacturing purposes and for tinder, was let for a small sum (see p. 74). Higher figures are, however, reached when we calculate the injuries on vines or cereal crops. Pierce,^ in 1892, furnished estimates putting the loss resulting from the Anaheim vine- disease in California at ten millon dollars. The area of infected land was about 25,000 acres, in great part with an original value of .300 to 500 dollars per acre, l)ut so dejDreciated in tile course of five years that it became worth not more than 75 to 200 dollars. In the Zritschrift fur Fjianzaih-anklintni 1893, the inter- national phytopathological commission gave, from estimates mates furnished by the Prussian statistics-bureau, a review of the losses in Prussia from grain-rust. Amongst other esti- mates we find that in 1891 the wheat harvest of Prussia reached a total of 10,574,168 doppelcentner,- which at 22 marks per d.c. = £1 1,459,690 sterling. Of this 3,316,059 d.c. or £3,593,758 was depreciated by rust. The rye harvest was 30,505,068 d.c. at 22 marks, of which 8,208,913 d.c. or £8,896,364 was depreciated by rust. Oats reached ' Thf California Viuc-Disfase. U.S. Dept. of At/rindfure, Bnll. 2„ 1S92, p: 15. - Doppelcentiie?- = 100 kilograiiime. ECONOMIC IMPORTANCE OF DISEASES OF PLANTS. 85 '32,165,473 d.c. at 16 marks, of which 10,325,124 (I.e. or £8,138,023 falls to be deducted on account of rust. Thus on the crops wheat, rye, and oats, the loss reached tlie sum of £20,628,147 sterling, or almost a third of the total value of the crops. The year 1891 was a very unfavourable one, but even taking the estimate at the half of the above sum we have a yearly loss by rust amounting to £10,000,000 sterling. In Australia the loss in the wheat harvest of 1890-91, on account of rust, has been estimated at £2,500,000 sterling. Consideration of the loss of sums of money like these, which might be considerably reduced if energetic and universal measures were employed against fungoid plant-diseases, will serve to em- phasize the importance of remedial measures. It must also be borne in mind that the use of diseased fodder,^ especially hay, grass or grain, infested l)y rust or smut-fungi, is productive of serious results to the various animals of the farm ; while the use of meal or Hour contaminated with smuts, stinking-smuts, or ergot is dangerous for mankind. ' Frohner, Lehrhudi d. Toxikologk f. Thkriirztt, 1890. CHAPTER A III. SYMBIOSIS. ^ 14. MUTUALISM. ]\Iutiuilisin, or Symbiosis in the stricter sense,^ has been distinguished as a special case of parasitism. This condition occurs when a parasite and its host mutually work for the Ijenefit of one another, each contributing to the other's nourishment. The lichens furnish the most conspicuous example. Here fungus-hyphae unite with algal cells, the algae furnishing- the fungi with assimilated organic nutriment, the fungi pro- viding water and dissolved salts for the algae. While it is by no means uncommon to find two organisms taking a mutual advantage of each other, yet mutualism in its strictest sense is a rare phenomenon. For it generally happens,, and is indeed to be expected, that one or both symbiotic organisms modify in some degree their mode of life to suit the altered conditions necessary for their mutual support. Thus amongst the lichens, as a result of the union of fungus and alga, a living organism originates, which in form, necessities, and mode of life is quite ntiv, and differs completely from either of its components. In the lichen-community, the fungus, alone reproduces itself; yet the alga occurs as a free organism in nature, while the fungus can only be reared in artificial culture. This combination might perhaps be compared with that of oxygen and hydrogen to form water, also to a certain extent with the union of the sexual cells to produce a new 1 The term Symbiosis was applied by De Baiy, (who introduced it), by Frank and otiieis, to denote tliose cases where a cohalntation or partnership was. observed to take place between two different organisms. (Frank, Lehrhuch (L Botanil; 1892). " Mutualism " was first used by Van Beneden. MUTUALISM. 87 individual. Tliese, and other examples, will serve to illustrate how we have in the lichen an organism with peculiarities of structure and of life, widely differing from those of either an alga or a fungus. This unification of two living beings into an individual whole, I have designated " Individuation." ^ In the case of the lichen-symbiosis, the chlorophyllous part consists of minute algal cells, completely enclosed in a tissue of fungus-hyphae, and the lichen lives as a perfectly isolated and independent plant. The case is, however, different where the fungus enters into parasitic relationship with the green cells of a large plant. Union may then take place, so that the fungus lives on, or inside its host, and removed from contact with any other substratum. The fungus is, however, not in a position to convey any nourishment to its host, and in fact is absolutely dependent on it for the organic substance and water necessary for growth. Where, however, the relationship is such that the parasitic fungus is still in contact with some other substratum, then it may be assumed that, in spite of its parasitism, it takes up nutriment from this source, and shares it with its host. This, as has already been pointed out, is the state of things in the lichens, where the fungus completely envelopes the small isolated algae, and must, as a condition of the growth of the lichen, remain in direct contact with the substratum ; the fungus is believed to take from the substratum water and inorganic food-material with which it supplies the algae, while it receives in return plastic organic substance to be used in its own growth. Of course cases do occur amongst the lichens, where, in moist places, the alga is not dependent on the fungus, or, on the other hand, where the fungus can itself take up organic substance from its substratum. Another example of the case is the union of fungi with non-chlorophyllous plants which inhabit humus (e.g. Monotrojm). Here the fungus takes up organic nourishment from the substratum and supplies it to the higher plant, which, in consequence of its lack of chlorophyll, is directly dependent on the plastic organized substance from the soil, supplied through the agency of the fungus. The latter, however, receives nothing in return ; it requires nothing, since its substratum offers it the most favourable conditions for nutrition. This form of ' Iiicli\-i(Uuili.siiuis. 88 SYMBIOSIS. symbiosis, in which the l'un<4us becomes the nurse or feeder, I distincruish as Xntricism. Between the case just cited and that in which the fungus is a pronounced root-parasite on greeu plants, there exists every possible intermediate stage. l>efore nutricism is considered in detail it would be well to exemplify briefly from the ranks of plant-parasites, that pheno- menon of individuation so sharply defined in the lichens. A large number of parasitic fungi cause local cell-enlargement and cell-increase, with the frequent result that an attacked plant- organ becomes very much enlarged and its form much changed. One speaks in such cfises of hypertrophy and hypertrophied organs. It is quite evident that in cases of hypertrophy the attacked part must be better nourished, otherwise it could never sustain the great increase in number and size of its cells. The hypertrophied organ is, in fact, indebted to the surrounding healthy parts for its additional nourishment ; in other words, the place of demand draws to itself the materials it requires. Tliis is all the more necessary when the region of increased growth is deficient in, or altogether devoid of, chlorophyll, and thus quite dependent on the assimilating green parts. This is frequently the case, as in the scales of alder catkins attacked by E.i'onscus alni incanae, in the needles of silver fir deformed by Accidmm elatinum, or in the yellow needles on spruce resulting from Arcidium coruscans. So also must the woody swellings of branches attacked by Accidium elatinum, Gymno- i^poranfjium mhinac, and other fungi, be produced at the cost of neighbouring parts of the host. The hypertrophied organs be- have, in fact, like these plant-organs — flowers, roots, etc. — which are normally deficient in chloropliyll, and to which plastic material must be supplied. In other cases the part of a plant attacked by fungi behaves like a specialized organ, and, in combination with the fungus, attains to a certain degree of independence. The so-called "witches' brooms" furnish an interesting example. It is a well- known fact that the direction of growth of the main axis of plants is negatively geotropic, whereas that of the lateral branches is only a modified form of this condition. If the terminal bud of a tree {e.g. a spruce or fir) be removed, then one or more lateral branches, or even buds of those branches, will exhibit an increased negative geotropism. This is very marked in MUTUALISM. 89 the case of the so-called " storni-tirs " of the mountains, on which are developed not a single apex, as in the normal fir, but many, each of which grows up like a little independent tree on the branches of the old stem. A similar result follows where a portion of a lateral branch is planted as a " cutting," one bud grows directly upwards, the others form lateral branches. The stimulating effect which the removal of the terminal shoot produces on lateral branches is thus one which extends to a considerable distance. A stimulus of a somewhat similar nature appears to be exerted on buds attacked by certain fungi, so Km. lii. — Witches' broom of Silver P'ir, caused by Aecidinm elati (V. Tubcuf pilot.) that the shoot produced from such a bud no hjnger retains its iiunual direction of growth, l)ut Ijecomes negatively geotropic like an independent plant. This marked negative geotropism is characteristic of all witches' brooms (Fig. 16), and shows clearly that they are no longer controlled by the same laws of growth as the normal lateral branches. They have in addition other peculiarities not exhibited by normal plants. Thus tlie witches' broom of the silver fir caused by mycelium of Accidium clatinum is not evergreen, but bears needles which fall each autumn. Moreover, no witches' broom bears fiowers or fruit ; for example, that on the cherry (Fig. 5) produces exclusively leaf-buds which unfold simultaneously with the 90 svMinosis. opening of the flower-buds of miattacked twigs, the normal foliage coming later. "We have here an expression of the existence of a closer syni])iotic relationship between the fungus and its host-l)ranch, than between that host-branch and its main branch. It also shows that the host-branch is completely at the service of tlie fungus, although the latter is dependent on the former for its support. The host-branch is, at the same time, under the necessity of conducting itself in the partnership in the way most suitable to the development of the fungus.^ Thus the asci of the Exoasceae are produced on the leaves of the witches' broom, and ripen as the normal leaves unfold, so that the spores are in a position suitable for successful infection of the young normal leaves. From these facts it can be deduced, that parts of plants attacked by fungi exhibit that kind of symbiosis with the fungus which we call individuation, the joint community Itehaving more or less as a parasite on the stem or branches of the host- plant. This is clearly the case where the attacked parts exhibit increased growth, and at the same time a diminished production of chlorophyll resulting from degeneration of chloroplasts. Such parts of plants are quite as individualized as the lichens, with the single distinction that they remain in communication with the parent plant and draw nourishment from it. There are, however, other cases where the chloroplasts are apparently increased, where at least they attain a lengthened duration of life. This is evident in certain instances first pointed out by Cornu, mentioned by I)e Bary, and on which I have made extended observations. Maples may l)e found in autumn on whose discoloured, withered leaves large green spots are still present. On Norway maple I have observed these spots, very conspicuous on almost every leaf, and especially on those of the lower crown. The green parts were beset with the white epiphytic mycelium and perithecia of Uncinula accris. Cornu describes similar appearances accom- panying another Erysiphe, certain Uredineae, and Cladosporiuvi dendriticum. I have seen the same phenomenon regularly on the mountain maple on leaves carrying lilack spots of RhytUma ^ Plant-galls causetl by animals also exhibit a(lai)tation.s serviceal)le only for the gall-occupant. MUTUALISM. 91 ptmctatuQii (Fig. 129). As other exumples may be mentioned quince leaves, which I infected with Gymnosporangmm davariac- forme, and leaves of Cynanchinn Vincctoxicv.m infested witli Cronartium asclepiadaiin. In all these cases, nutritive sub- stances seem to be still transmitted to attacked parts after death of the rest of the leaf. The attacked spots show also an independent behaviour in that they do not turn yellow before the fall of the leaf, l)ut continue to work at the service of the parasite. One can even believe that these green islands, so long as inorganic substance and water are supplied to them, live with the fungus like lichens, especially those lichens whose algae obtain water and inorganic material direct, not tlirough the fungal-hyi^hae. CHAPTER IX. SYMBIOSIS. ij 15. NUTRICISM. FoK the greater number of the facts u.sed in our discussion of this peculiar phenomenon, we are indebted to Frank, who laid the basis of our knowledge in regard to it. We have chosen the expression Nutricism for reasons already stated (§ 14), and would only add that its scope is variable in different cases, and reaches its most comprehensive application in connec- tion with Frank's views on the so-called mycorhiza. We shall best explain the phenomenon by describing individual examples. In a number of cases the symbiosis between fungi and higher plants does not result in the fungus being supplied with organic nutriment by its host, but rather that the fungus is in no way indebted to the host-plant for nutriment, and may even, as in the lichens, convey solutions of inorganic materials to it, thus assist- ing in its nutrition. There are two cases distinguishable in this connection. In the first, the fungus lives in humus and in close external contact with the roots of its host, obtaining I'ood for itself, and at the same time supplying its host with organic nutriment. In the other case, the fungus develops inside the root-cells of its host, and is probably nourished from that source, till on dying it gives up certain albuminoid sub- stances, which are absorbed and utilized by the host-plant. The parts of the roots which shelter the fungi, Frank has named " fungus-traps," the plants themselves being " fungus-digesting plants." The organs resulting from the symbiosis of root and fungus NUTRICISiM. 93 have been named niycorhiza ^ or fungus-roots. Where, however, new structures (swellings, etc.) are produced on the roots, as a result of symbiosis with fungi or bacteria, the name mycodomatia or fungus-chambers has been applied. One division of niycorhiza consists of those which live in humus, and act as intermediaries in supplying their hosts with nutritive material. In this case the fungus covers the host- root like an outer covering, forces itself between the cells of the outer layers^ and produces haustorial branches in the interior of the host-cells. These Frank designates as ectotrophic mycorhiza. The remaining mycorhiza do not form such an external sheath, but live inside the fungus-traps, and produce tangled coils of hyi)hae in the root-cells of the host. These Frank distinguishes as endotrophic mycorhiza. Ectotrophic Mycorhiza. (1) On non-chlorophyllous plants living on humus. Kaminski - was the first to observe that Monotropa hyjx/pitys, a non-chlorophyllous plant living rooted in forest-mould, possessed a compact root system devoid of root-hairs, but covered with the hyphae of a fungus. At the same time, he expressed the belief that a symbiotic relationship existed between the fungus and the roots of Monotropa, whereby the former supplied nutriment to the latter. The fungus clothes the growing point, and extends backwards to that part of the root which has ceased to elongate: there the mycelium penetrates -^ inwards between the root-cells,, and remains intercellular. The mycorhiza of Monotrojjo thus showed complete agreement with those known earlier on the roots of Cupuliferae,* and since proved by Frank to have a very general distribution. Johow ^ has pointed out that an external mantle of fungi also exists round the root-apices of Hyinqntys hyiwphacgca , a holnsaprophytic plant devoid of chlorophyll. ' Siuiunv, Kodsymhiose or/ Mycorrhizer saerluj ho^ Skortratrne, 1893. With IJiblirigiapliy. -'K li-t^ i- : a, fungoid mantle; l>, fungoid tissue between the cells of the root, rendering them unrecognizable except by their large nuclei ; the inner parts contain no fungi, (v. Tubeuf del.) ]\Iy newest investigations on this subject ^ show that, amongst the gymnospermous forest-trees, the Abietineae alone have roots externally clothed with a fungus ; the remaining groups have all endophytic niycorhiza. The Abietineae have frequently only ji fine mantle of fungus on their rootlets, and do not produce the tufts of short, branched roots so characteristic of mycorliiza in general. Frank does not seem to be altogether correct in his view that the Abietineae are almost or quite incapable of multi- plication by slips, because they would then require to exist for a time without niycorhiza. Probably there is some other reason for this, because the Salicaceae (e.f/. Poplars), which have typical coral-branclu'd niycorhiza, are almost exclusively multiplied l)y slips. ^ Hoveler, ("ilb. die Verwerthiing <1. Huniiis hei d. Eniiihrung d. chloropliyll- fiihrenden Pflanzen." Inuug. Diss., Berlin, 1S92), states that roots are able to utilize the soil-constituents without aid of fungi. -Tubeuf, For.sl.-natu7-ivi>is. Zeilschrift, 1896. ECTOTROPHIU MYCOItHIZA. 97 After the mycorhiza have functioned as such for some thue, the fungoid sheath, as well as the hyphae contained in the cortex of the root outside the endodermis, are thrown off by internal cork-formation. This is, however, not always the case, for the fungus may penetrate further and develop injurious para- sitic characteristics; this is so with Pohjsnccum} and Eldphomijcr^ir Endotrophic Mycorhiza. (1) On non-chlorophyllous plants living in humus. Certain Orchideae — N'rottin Nidus ary and Wor. (U. S. America).- This produces, especially on Taraxacum, warty galls composed of a diseased epidermal cell, enlarged and surrounded by a wall of 'Schroeter: Cohn's Beitriuje z. Biol. d. Pflanzenl., 1875, and in Eii;//fr-/'raii/l Pflanzenfamilien, 1892. De Bary and Woronin, Berkht. d. natfomrh. Gta. zu Fi-eiburc/, 1863. - We propose to indicate in this way species recorded in Seymour and Farlovv's "Host-index" for North America ; "^ British species by (Britain). (Edit.) 8YNCHYTKIUM. 109 less swollen neighbouring epidermal cells. The sporangia contain reddish-yellow drops of oil, so that the swellings a})pear yellow. The organs attacked are much distorted and more or less stunted. The same fungus occurs on other Compositae, and is pro- bably identical with S. smi- f/iiineum of Schroeter, which produces dark red, crusty swell- ings on Cirsium palnMrc and Crqjis biennis. Along with S. tarcuxtci one often tinds Olpidium svmidans. S. fulgens, Schroeter (U. S. America), produces reddish- yellow swellings on the leaves of Oenothera biennis and 0. , ^. l-'ic. 25.— Si/nchylriuu, f. .,..:...■,. Leaves of muncata ; when reSting-SpOreS Taraxamm qjndnaU so dt^fumiud by the fungus ,, „ , , that the laminae are all more or less vindeveloped. appear they form brown crusts, (v. Tubeuf phot.) The sori of zoosporangia are detached from the host-plant as single sporangia, which become scattered over the leaves. S. trifolii. Pass. ( = Olpidinm trifolii, Schroeter), is as yet little known. Other American species are : — S. papillatum, Farl., on Geranium. S. decipiens, Farl., on Am2}hicar2}aea. S. vaccinii, Thomas,^ on Vaccinium, Ganlthcria, K(dinia, FJiododcndron, etc. Pycnochytrium. The sori of zoosporangia are not produced directly from the mature sporophore, but the contents of the sporophore pass out by a fine opening and form a thin- walled vesicle, the prot(jplasm (tf which breaks up into sporangia. Schroeter divides the genus into two sul)-geuera. {A) Mesochytrium. The discharge of the original sporophore 1 Halsted, " Cranberry gall-fungus " ; N. Jersey Ayr 18S9. With figures. Coll. BuUe(. 64, Dec. 110 PHYCOMYCETES. and the formation of zoosporangia take place in the cells of the living host-plant. In addition, spores are formed which have a resting period. (B) Only one kind of spore is formed ; it has a resting period, and only proceeds to produce soi'i of zoosporangia after decay of the host-plant. (a) Chri/sochi/trium : protoplasm contains a yellow oil. (b) Lcncochytrivm : protoplasm colourless. Each of these divisions is sub-divided into forms with simple vesicles, and tliose with compound. Mesochytrium. Synchytrium (Pycnochytrium) succisa^, De Bary and Wor.^ This parasite forms warty swellings and ellow spots, generally 6 ^7 Fio. 26. — Simchylriv.M sv.ccisae. A, A mature sporocarp inside its host-cell. B, In the upper part of the cell a sorus of swanu-sporangia after escaping from its covering, which lies below it. C, Isolated swarm-sporangium. D, Swarm- spores. (After Schroeter.) on the radical leaves and l)ase of stem of Scahiosa succisa. Infection is brought alxjut in damp situations by means of swarm-spores. These have a single ciliuni, and bore their way into the host-cell. After entrance, they produce a plasma-mass, which becomes enclosed in a delicate membrane. The cell so formed sprouts at its uppermost pole, and gives rise to a new spherical cell, into which the older discharges itself In the second cell numerous small sporangia are formed, so that it represents a sporangial sorus ; beside it is always found the empty membrane of the first cell. The sorus breaks up later into single sporangia, which on opening, set free their contents * Schroeter, " Pflanzenparasiten tuis d. Oattung Sj'iichj'triuin." Cohn's Beitr. :. Biolog. d. PjJnir.eii, 187"). PYCNOCHYTRIUM. Ill as zoospores swarming by means of a ciliuni. In acUlition, resting-spores are developed singly or in groups. The first effect on the host-cell of the entrance of a swarm- spore is that it becomes distinctly larger. At the same time neighbouring cells are so stimulated that they multiply and form a prominent ring-shaped swelling. The sporangia discharge their zoospores on the host-plant itself, and these pass into other cells of the swelling ; here they form resting-spores and the host-cells die. Schroeter states tliat the resting-spores may 1)6 found from August onwards. S. stellariae, Fuck. On Stellaria media and S. nemorum. The reddish-yellow her. ^spherical swellings are produced on leaves, stems, flower-stalks, a .d sepals, either isolated or as a crust. The resting-spores ger'^rally form brown crusts. The host-leaves may be somewhat c^ Ipled, but beyond this undergo little de- formation.^ ' Chrysochytrium. ( 1 ) Forming simple vesicles : Synchytrium myosotidis, Kiihn (U. S. America). Tlie t\)\- denaal cells when attacked swell up to form club-shaped processes, while the cells with no fungus remain unaltered. The normal hairs of the host-plant are fewer on diseased than on healthy parts. This parasite attacks IJoragineae, c.y. Myoxofis ■stricfa, LifJiosj)crnnim arvcnsc. S. cupulatum, Thomas, produces red eruptions on Pot cat ill o arffcntid and Driias ocfoprtala ; diseased cells of tlie host-plant contain red sap. S. punctum, .Sorokiu. On I'lanfafp lanccoJata and P. nmliK. S. laetum, Schroet. On Gagca. (2) Forming compound vesicles : S. aureum, Schroet. Attacks many herbaceous plants as well as leaves of many shrubs and trees. Frequent on Lysimdchin Niommnlaria, Fragaria, etc. The cells attacked are swollen and enclosed in a patch of enlarged neighbouring cells. S. pilificum, Thomas. On Potent'dla TormcntUIa. The vesicles are hemispherical, and bear on their summits a tuft of abnormally elongated hairs. Thomas- found this species 1 Clendeniu {Botanical Gazette, 1894, p. 296) describes and figures a Si/nchy/rhm on Stellaria media in America (Edit.). -Ber. d. di'utsch. hotan. Ges., 188.3, p. 496. 112 IMIYCOMYCETKS. on steins, flower-stalks, radical and cauline leaves, and floral envelopes. Leucochytrium. (1) l''(iriiiiiiu- simple vesicles: S. punctatum, Sehroet. On G(uirii prafcn^^ls. S. rubrocinctum, Magnus, forms little red eruptions on Saxi- frafja iji'aiiiilntd, the cell-sap of the host-plant becoming red. S. alpinum, Thomas. On Viola hiflom. S. anomalum, Sehroet. (U, S. America). On AiJu.ia Moscha- ti'llina, less common on Ranunculus Ficaria, Isopijrurii thalictroidcs and Rumi'x Acctosa. The size and shape of the swellings, as well as of the spores, are very variable. (2) Forming compound vesicles: S. anemones, De Bary and Wor. (U. S. America). On A/u/none ncmorosa, A. ranunculoides and Thalictrum 2'^urpura- ^^^.y^M h ^d-A Fio. •n.—Synchytrium anemones. The sporocarps form black points on leaves, petioles and perianth of the Anemone ; the laminae are also stunted and distorted, (v. Tubcuf del.) sccas, attacking stems, leaves, ur flowers, and forming eruptions whose cells contain a red sap. In very bad cases, crumpling and swelling of attacked organs occur. PYCNOCHYTRIUM. ll.S S. globosum, Schroet. Wliere the attack is severe, this causes pearly swellings or incrustations ; it frequents plants like Viola, Galium, Achillea, Sonchus, 3fi/sofis. S. mercurialis, Fuck., is very common on Mercurialu pcrcnnis though st'ldoni injurious to it. One severe case is thus de- scribed by Schroeter : " In spring the stem of the plant was covered by a thick uneven glassy crust, which in course of time became raised into wing-like processes running down the stem and coated on both sides with white granules of the immature parasite ; the leaves were completely rolled together, crumpled, and covered with glistening prominences as with fine silver sand. The plant in this condition developed poorly, scarcely flowered, and soon died, so that by the end of September few diseased examples could be found." CLADOCHYTRIACEAE. The vegetative body is frequently a l)ninehed mycelium. It lives intercellular as a saprophyte, or intracellular as a parasite, and forms intercalary or terminal swellings, in which zoospor- angia or resting-spores are produced, then it disappears. Sexual reproduction does not occur. The parasite lives in and forms swellings on aquatic plants, or land plants in moist situations. The genera Urophlyctis and Physoderma contain species parasitic on higher plants ; together with the saprophytic Cladosiioranfjivm, these are regarded by Fischer as sub-genera of Cladochytrivvi, and as such they are also here regarded. Urophlyctis has both zoosporangia and resting-spores, Fkyso- dcrma has only resting spores, CladosjMiranfjiinn only zoospor- angia. Urophlyctis. The delicate mycelium is . unl)ranched, or only sliglitly branched, and lives endophytic, boring through the walls of the host-plant. At the place where a hypha enters a host- plant it forms a swelling or collecting cell (sammelzell), which generally becomes differentiated into a larger cell rich in contents, and an outer smaller one with few contents, but with fine terminal bristles. From the collecting cells new hyphae originate and produce other collecting cells in neighbouring host-cells. The zoosporangia are situated outside the host-cells, 1 1 4 I'HYCOMYCETES. but send a hyphal process inside, which branches into a tuft ■of rhizitiils. IJestiuLi-spores niav be found, several in each cell. Cladochytrium (Urophlyctis) pulposum, (Wallr.), causes on leaves, stems, and Howers of C/wnopodium and Atriplex glassy -swellings, in the undermost cells of which are situated the zoosporangia. The resting- spores have brown shining walls and lie inside the cells. The zoospores are uniciliate. CI, (Ur.) butomi, IMisgeu. On leaves of Butomus umhcllatuH. Black spores are produced C(nitaining resting-spores. The col- lecting cells have tufts of hair. Physoderma. Zoosporangia are absent. liesting-spores formed, several in •each host-cell. Cladochytrium (Phy.) menyanthis, De Bary (U. S. America). On leaves and petioles of Menyanthes trifoliata this forms vesicles containing resting-spores. The collecting cells have terminal hair-tufts. Diseased leaves are generally smaller than Ileal thy. CI. (Phys.) flammulae, Jitisgen, forms little swellings on leaves of Ranvnculn^i Fhun inula. CI. (Phys.) Kriegerianum, Magnus, causes transparent swell- ings on Ciiruiii (Jar /'I. CI. (Phys.) iridis, De Bary, on Iris pseudacorus. F'ischer mentions other species on Scirpus, Alisma, Bammcuhos, FotentAlla anserina, Silaus pratensis, Sium lafifolivm, Phalaris, Glyceria, Sympliytum, Mmtha, Rvmcr, Allium, etc. Prunet ^ describes Cladochytrium viticolum as the cause of the nmch-discussed Bruiiisure of vine ; also CI. mori as a new disease of the mulberry.^ The .same authority^ de.signate.s as Pyroctonum sphaericum, a ])arasite on wheat, which has become very abundant in Soutliern France. (2) ZYGOMYCETES. Unicellular fungi. Sexual reproduction does not take place by the fertilization of an ovum in an oogonium by an antheridium, 1 Prunet, Gomjit. rmd., 1894. - Prunet, Compl. rend., cxx., 1895, p. 222. 3 Prunet, Compt. rend., 1894, ii., p. 108. ZYGOMYCETES. 1 1 5 but by conjugation or union of two cells of the mycelium .separated off from the ends of two hyphae by transverse walls. As a result of conjugation, a zygospore is produced, which is a restiug-spore and corresponds to the oospore of the Oomycetes. The zygospore puts forth a germ-tube, which becomes a mycelium bearing sporangia on sporangiophores. From each sporangium, spores, never swarm-spores, are set free, germinate, and produce & mycelium. Sporangia similar in form to the zygospores may be asexually produced on the mycelium. The unicellular and much-branched mycelium grows into its substratum, and is nourished as a rule saprophytically. The JSntomopkthorcar cause important insect-diseases on Muscidae, Cabbage Butterflies, and caterpillars of Trachea jnniperda (the Pine Beauty). Another common group of the Zygomycetes, the Mucorini, penetrate into bruised places in living fruits, and produce decay (see p. 180). Some other Zygomycetes are parasitic on fungi (Coni((ioholHs), some on animals. (3) OOMYCETES. These fungi possess a one-celled and much-branched mycelium. In their vegetative structure they most nearly resemble algae like Vaucheria. Eeproduction is brought about, asexually by means of swarm-spores formed in sporangia (conidia also occur) ; sexually by oospores derived from oogonia and antheridia. There are three families of Oomycetes : Saprokfjniaccar, Mono- hlcpharideac and Pcronosporeae. Two of these groups contain parasitic forms : Saprokgniaccac (cjj. Achyla prolifcra, dangerous to Fish and Crustaceans) ; and Pcronoqjorcae. PERONOSPOREAE. The greater number of the Peronosporeae live as parasites in the tissues of higher plants, and obtain nourishment generally by means of haustoria. The mycelium, in earlier life at least, has no dividing septa, and generally grows in the intercellular .spaces of the host-plant, and sends haustoria into the cells. Eeproduction is effected asexually by formation of swarm-spores in sporangia, and sexually by means of oospores. The latter are produced from the fertilization of an ovum in an oogonium by an antheridium whose contents pass through a fertilization-tube penetrating the 1 1 6 PHYCOMYCKTES. oogoiiiuni wall.^ No formation of speruiatozoids occurs, as is tlie case in VoMchcria and other groups of algae showing close rela- tionship to these fungi. In certain cases the formation of swarm-spores in sporangia does not take place, but conidia are produced, which germinate directly into a mycelium. Preventive measures against the whole group consist in destruction (by burying or burning) of diseased and dead parts of host-plants which contain the hibernating oospores ; by change of crop on infected fields ; and by treatment with copper reagents (see Chap. VI.). To the Peronosporeae belong the genera Fytliinin, Fliiitnpli- fhora, Ct/siajms, Basidiophora, Flasmopara, Sclerospora, Bremin and Prronosiwra. Pythium. The mycelium possesses no haustoria, and grows both between the host-cells and inside them. Cross-septa are not present at tirst, but later these may be found at irregular intervals. Pythium lives as a parasite in living plants, or as a saprophyte on a dead substratum. The conidia are of various forms, and either germinate directly into hyphal filaments, or discharge their contents into a bladder where zoospores are developed and liberated as free-swimming spores with two lateral cilia. The oogonia contain only one ovum-cell, which is fertilized by means of an antheridial tube applied to the oogonium. The thick- walled oogonia on germination produce hyphae or discharge zoo- spores. Pythium de Baryanum, Hesse ^ (Britain and U. S. America). This i)arasite is injurious to the seedlings of various plants in gardens and fields. Some of its commoner hosts are maize, clover, mangel, millet, and many species of the Cruciferae ; it has also been found on the prothalli of Uquisctum and Lycopodium!^ It may also attack living or dead leaves and tubers of potato. The sporangia have a lateral beak-like outgrowth, into which the plasma passes and divides into biciliate zoospores. The ' 111 many species the feitilization-tube remains closed e.g. Plasmoj^ara ri/ico/a. -Hesse, Pythium de Baryanum, Halle, 1874. Atkinson (Ccyrnell Univ. Af/ric. Expt. SfaL, Bull. 94, 1895), describes and figures this and other fungi causing " Damping-off. " (Edit.) •' Sadebeck, Naturforsch. ■ Versammluufj. , 1 876. PYTHIUM. 117 sporangia, however, may tirst pass through a resting period. Sexual reproduction consists in the impregnation of an egg-cell by means of a fertilization-tube from an antheridium. The oospores are formed singly in each oogonium, and are liberated only after decay of the oogonium walls and the tissues of the host-plant containing them. After a resting period they pro- (hice a germ-tube, which penetrates into the host-plant and becomes a delicate branched colourless intercellular mycelium. Hil)ernation is accomplished both by these oospores and by resting- conidia, which remain amongst the decaying plant-debris on the ground. Humphrey has observed sickness and death of cucumber seedlings as a result of Py. dc Baryanum. Wittmack found a species {Py. Sadchcckianum) very destructive on peas and lupines ^ in various localities ; it has been observed freipiently since. Py. gracile is parasitic on algae. Py. dictyospermum, Rac. occurs in Spirogyra. Py. cystosiphon is found on species of Lenxiia. Py. intermedium frecjuents prothalli of vascular cryptogams. Phytophthora. The mycelium is at first non-septate though nmcli branched. It grows both between and through the host-cells, and in some species, {e.g. Ph. omnivora), has small haustoria. The conidiophores branch and produce a large number of conidia or sporangia in succession. The first conidia are terminal, but are displaced towards one side and thrown off by further growth of the conidiophore to produce other conidia. The sporangia distribute their contents as swarming cells wiih two lateral cilia; the conidia produce a hypha directly. The iea(l duiing suiniiier by coniilia, or swanuiiiL,^ cells prdduced tioni s[M)raiigia. The passage through ^vinter is effected by means of oospores, resulting from fertiliza- tion of an ovum in the oogonium l)y a fertilization-tube from an antheridium. The intercellular mycelium is at first nonseptate, later septate, and forms small haustoria. Seedlings of other plants, besides those already mentioned, and also succulents (e.g. Sempcrvivum and Cactus} may be attacked and killed by this same fungus. This epidemic cannot well be combated except by methods applicable only in the nursery. The most effective method is to plant no young seedlings in plots which \m\e already been diseased, but to reserve such plots for older plants to which the fvmgus is not dangerous. If the disease be not very general,, attacked plants may be removed singly and destroyed. Since moist air is very favourable to distribution of the disease, all nettings or trellises should be removed from seed-beds^ threatened l)y attack. In dry airy localities there is less, danger to seedlings than in moist. The fungus often appears, in such force that seed-beds of beech or conifers are denuded of every plant within a few days, and in the forest beech- seedlings may, during damp weather, 1)6 completely exterminated over great areas. Km. 2S. — l'li}/loi>lil/ioi-(' Oiiinivora. Cotyledon? .ind i)riniiiry leaves in early stage of attack : the disease forms brown spots where patches of mycelium are developed, i natural size. (V. Tubeuf del.) PHYTOrHTHOKA. 119 Another parasite of conifer seedlings — Fusovio. 2)arasiticmn — which somewhat resembles Phyfophfhora, is figured and described amongst the " Fungi imperfecti." Phytophthora infestans, l)e Bary.^ This parasite was first observed in Kuro^te in 1845, and has since then become FiO. 29. Fio. 30. Fig. 20.— Cellular tis.suc from diseased cotyledon of Beech. The starch-grains have been absorbed from the cell-protoplasm which has shrunk awaj- from the cell-wall a ; b, (>, intercellular fungal hyphae with very tiny haustoria ; c, c, fertilized oogonia, each containing a .single oospore. (After K. Hartig.) Fio. 30.— Phi/tojihlhora omnii-ora on the epidermis of a Beech -cotyledon, c. Outer wall of epidermal cell; li, cuticle; c, hyphae growing between cell-wall and cuticle, causing the shght protuberance d; e, spot where a hypha has emerged through the cuticle and developed as a sporangiophore/; after the first sporangium has reached maturity a second begins to form, n atid h, whereby the first is displaced ; A-, a stoma from which sporangiophores have developed. (After R. Hartig.) only too well known. It attacks leaves, shoots, and tubers of potato and other Solanaceae, e.g. the tomato (S. Li/copersicum). The potato leaves become discoloured, brown-spotted, and crumpled, especially in damp weather. The sporangiophores (gonidiophores of De Bary) issue from tlie stomata in 1 De Bary, Journal of Botany, 1876, and Journal of the. Royal Agrir. Society, 1876. 120 FHYCOMYCKTES. tufts, iuul tt)nii a white bonier round the brown parts of the leaf; they are monopodially branched and produce terminal sporangia (gonidia), which are easily detached. The sporangia on germination either pro- duce a varying number of zoospores, or germinate directly like conidia to form a mycelium capable of pro- ducing new conidia. The potato -disease is distin- guished from Phyto])htliora omnivora in the absence of sexual reproduction by oospores.^ It is generally assumed that the mycelium hibernates in potato-tubers, from which the fungus recommences to spread in spring. Boehm,- however, contests this, and holds the hibernation of the fungus to be quite unknown, and that from the tubers of Fio. 31.-Suiface of a Beech-seedling with swarm- a disCaSCd plant, either a spores a, h ; the germ-tubes from tliese penetrate ^ between adjacent epidermal cells ; c, sporangium with health V plant Or llOUC at zoospores already germinating inside it, d, f\ e, -a J r , germ-tube which has penetrated directly into an all reSultS epidermal cell; jr, germ-tube which, after growing stlla lw.,m paslorin. The fuiigUK has caused distortion and thickening ; the white porcellanous conidial cushions shew up distinctly on the dark background, (v. Tubcuf phot.) swarming spores with two unequal lateral cilia. The egg-cells, produced singly in each oogonium, are fertilized by an autheridiuni. The thick-walled oospores remain enclosed in the intercellular spaces of the host-tissue, and on germinating in spring discharge swarming spores. Cystopus candidus (Pers.) Lev. White liust. This fungus 124 I'HYCOMYCKTES. is very frequent on wild and cultivated Cruciferae throughout the wliole world, and causes deformation of shoot, leaf, and tiower. Fig. 31. — Ci/Ktopus caHdiihtn. B, Conidiophores isolated from the cushion ; the conidia or sporangia are united by intermediate cells. C, Sporangia breaking up to form swarm-spores. D, Swarm-spores escaping, is', Swarm-spores in motile condition. /■', Swarm-spores come to rest and germinating. G, Two germ-tubes entering a stoma of Lepidium sativum ; the stoma is shown from the inside, so that the spores from which the germ-tubes arise are pn the outer surface and unseen. (After iJe Bary.) Fio. 35.— Flower of Radish (Raphanus sativus) hypertrophied by Ci/stojms caaduli's. The much-enlarged ovary stands out in the centre. The anthers are leaf-like ; the petals are mucli enlarged and hang downwards ; the sepals are somewhat enlarged. (Specimen from Botanical Musoinn of Krlangcn, and ph(jtographed by Dr. Bnnis.) The conidial cushions form thick white stripes with a porcellaneous appearance, by which they are easily distinguished from the cushions of Piromspora parasitica often present on the same plant. CYSTOPUS. 125 Besides conidia, spherical oospores may also l)e present ; these are generally produced on the stems of the liost-phmt, Imt also on Hower-stalks and ovary-walls. The spherical conidia arise in simple chains on short coni- diophores, and are loosely connected by tiny intermediate cells. The conidial cushions rupture the epidermis and the ripe conidia fall off to produce biciliate swarming cells (Fig. 34), These give rise to germ-tubes which enter the stomata of seedlings and Fig. 36.— Flower of Radish hypertrophied by Cystopv.i cundidv.s. The white .«;wollen conidial cushions occupy the enlarged petals, sepals and ovaries. (Dr. Bruns' phot.) develop to intercellular mycelia, tine short lateral twigs of which pierce the wall of the host-cells and become little spherical haustoria. The oogonia arise as thick-walled spherical swellings on the mycelium. The antheridium, after applying itself to the oogonium, widens and projects a fine fertilization-tube through the wall to the egg-cell. After fertilization is effected, the egg-cell is enclosed in a firm uneven membrane, and hibernates inside the oogonium. In spring the plasma of the oospore forms numerous biciliate 12G rHYCOMY(JKTE.S. swarm-spores which escape from the enclosin<^ coats and germinate on seedling ])lants. De Bary ^ found germ-tubes of Cystopus entering all the stomata of Lcpidium sativum and of Ccq^sella, but they only developed further if the part attacked were the cotyledons. Magnus '^ observed an infection of Raphanus Raphanidrum in which the unopened buds were infected by swarm- spores. Oogonia may be found in the Howers of this same plant, whereas conidia alone only are present in CapiicU((. White rust is most cbnnnonly observed on Capsella, causing slight local swelling or marked hypertrophy. It is also found to injure radish {Raphanus sativus), horse radish {Coehlcaria armoracia), cress {Lcpidium mtimim), species of cabbage and turnip (Brassica Nap)us, B. nigra, B. Rap)a, B. oleracea), wall- flower (Cheir- anthus Cheiri), water cress {Nasturtium amphibium, etc.), caper-plant {Gapparis spinosa), and other wild and culti- vated plants belonging to, or closely allied to the Cruciferae. Wakker^ investigated the changes l)rought about on a number of Cruci- ferae by Oi/sfajms. Some plants showed little or no deformation or anatomical alteration, others showed much. While the anatomical changes in the various species examined agreed in general, yet. some showed a predominant or exclusive formation of conidia, others of oospores. The changes Fig. '.iT.—Cystopus poriiUacac, D. C. m, mycelium ; ./', basidia ; c, spores with intermediate cells. (After Tiilasiie.) ' Morpholoa.ra viticota. Conidiophores, much enlarged, (v. Tubeuf del.) tion in rain-drops discharge six to eight swarming cells from which germ-tubes grow into the epidermis of the host-plant ; thus the disease spreads rapidly during moist weather and a Peronospora vtticola, 1890. Magniis, Witt7)iarJ:'s Gartenzeit, 1883. Scribner, Iie2Jort of U.S. Dtqit. of Agriculture for 1S86, pp. 96-105 ; this contains an excellent account of this mildew. Articles on this subject dealing with remedial measures are frequently published in the U.S. Amer. Department reports an.l bulletins, in the bulletins from experimental stations, and in the horticultural journals. 1 Seymour and Farlow give it as occuring on every American species of Vitis. I 130 PHYCOMYCETES. wet season is veij favourable to it. The mycelium is non- septate and spreads through the intercellular spaces of the host, nourished by button-like haustoria sunk into the host-cells. The antheridium comes into contact with the oogonium by a fertilization tube, wliich, however, remains closed. The oospores hibernate in leaves and fruit. Prevention} Ammoniacal copper carbonate solution, eau celeste, or Bordeaux mixture, prepared as described on p. 69, may be used. The tirst-named solution seems least liable to injure the foliage ; the others must, on this account, be used with care. The first application is made about the time the Fii;. 41. — Plasmopara pygmaea on Anemone nemorosa. Conidiophores emerging from a stoma. Intercellular mycelium with haustoria. (v. Tubeuf del.) berries are well formed, and the sprayings are repeated every twelve to fifteen days, or oftener if there are heavy rains, till the grapes begin to colour. It must, however, be remembered that sprayings of this kind do not reach the mycelium inside the leaf, but only act superficiall}^ killing any developing conidiophores or conidia which may alight on the leaf. These fungicides are, at the same time, remedies for powdery mildew (Uncinula). " Sulphuring" as a remedy for this aiid the powdery mildew has been recommended by continental writers.^ The burning of all diseased vine-leaves is strongly recommended. Attention also sliould be given to the cultivation of disease-proof varieties.^ PI. pygmaea (Uiiger). On Rauuiiculaceae (Britain and U.S. Anuiiica). PI. pusilla (De Bary). On Geraniums. Uialloway, "Fungous diseases of the grape and their treatment," U.S. Dept. ofAably identi- cal with last. P. viciae (Berk.) (Britain and U.S. America). A dangerous species to many Papilionaceae (especially peas, beans, tares, lentils, etc.), often causing great damage to field crops. In recent years the new fodder-plant Lafhyrnfi si/lirsfris has been frequently attacked .^ P. trifoliorum, De Bary=* (Britain and U.S. America). Dis- tinguished from the preceding form by its irregularly marked 'Kiihn, Botan. Zeilung, 187.'>. - Zeituchrift f. Pflanzenkranklmtot, ii., p. 225 and 28;i. ^ Smith, Diseanes of Crops, London, 1SS4. PERONOSPORA. 133 oospore-coat (oospores of P. viciac have a coat with a regular net- work). It occurs on stems, leaves, and petioles of clovers, lucerne and other Papilionaceae, often with disastrous effect. P. sparsa, Berk. (Britain and U.S. America). This parasite on the rose was first observed in England. It injures indoor roses, causing a fall of the leaf, preceded by the appearance of lilac-coloured spots which, on the underside of the leaf, are closely beset with a white coating of conidiophores.^ Fk;. i'i.—Pi:ronos,mra viciac. Coiiidiophurus and conidia. (v. Tubcuf del.) P. arborescens (Berk.). On leaves and shoots of wild and cultivated i)oppies ; especially injurious to seedlings of garden species. P. parasitica (Pers.) (Britain and U.S. America). This pro- duces greater or less deformation of attacked stems of many wild and cultivated Cruciferae. Amongst cultivated plants the most liable to injury are the varieties of turnips and cabbage, radish, rape, cress, wallflower, also the mignonette. It is generally found along with Cystopus candidus on shepherd's purse {CapscUa). P. cytisi, Rostr.,2 attacks seedlings of hiburnum in Denmark, causing death in a few days. The leaves become brown spotted, ^ Zeitschrift f. P.-krank., ii., p. 386, (description of attack in Silesia.) -Rostrup, Zeitschri/t f. Pflanzenkrankhtitai, 1892. Magnus, JJedwigia, 1892. 134 niYrOMVCKTES, and l.tranehed coiiidinphores with light-lirown conidia arise from their underside. Numerous oospores may be found in the leaves. Kirchner ^ observed the disease on leaves of four-year-old plants, yet without injurious effects. The following are other British or American species : Peronospora ficariae, Tiil. On Ranvnculus, Mi/osnrns, etc. P. corydalis, De By. On Corydalis and Dicentra. P. violae, De By. On Viola tricolor. P. arenariae var. niaci'ospora, Farl. On Silene. P. alsinearum, Casp. On Cerastiuni. P. claytoniae, Farl. On Claytonia. P. lini, Sihroet. On Limim. P. potentillae, De By. On Rosaceae e.g. Geum, Fragaria, and Potentilld, P. Arthuri, Farl. On Oenothera. Fia. 44. — Pcrono.ijiora alsinearum. Sexual organs, o, Yomig condition ; 6, for- mation of ovum and fertilization-tube ; c, after fertilization, (periplasm some- what contracted by preparation, and the fertilization-tube unusually thick) ; 11, anthoridium ; o, oogonium, x 3f)0. (After De Bary.) P. leptosperma, De By. On Compositae e.g. Arte^nisia. P. Candida, Fuck. On Androsace and other Prinuilaeeae. P. cynoglossi, JJurrill. On Cynoglossurn . P. myosotidis, De By. On Myosotis and Echinos^^ermum. P. sordida, Jierk. On Nicotiana and Scrophularia. P. hyoscyami, D. By. On Tobacco in America and Australia {Uard. Chron. ix.). P. linariae, Fckl. On Linaria. P. grisea, X'wj.. On Vei-onica. P. lophanti, Karl. On Lophcmthv.s. P. alta, Fckl. On I'Inntago. P. (Plasmopara) cubensis is reported- as causing an extensive and destructive disease of cucumbers {Cucumis and Cucurbitd). P. (Plasmopara) australis, Speg.- On Echinocystis lohata and Sicyos angtdatnH in America. ' Kirchner, ZeiUchrift f. Pflanzaikrunkheiten, 1S92. -Humphrey, Report of (he. Mans. Af/ric. Exper. Stal., 1S90-92. Massee, Gardener's Chronicle, Vol. xvii., p. 656, 1S95. HIGHER FUNGI. 135 P. oxybaphi, Ell. and Kell. On various Nyctaginaceae. P. polygoni, Thiiiii. On Polygonum. P. euphorbiae, Fuck. On Euphorbia. P. urticae (Lib.). On Urticaceae. P. elliptica causes death of lilies. ^ B. Higher Fuxgi (Mycomycetes). The higher fungi are distinguished from the lower in possessing a mycelium, which, from the first, is divided by means of cross- septa. The mycelium of the lower fungi, though often much branched, remains unicellular till cross-septa arise on formation of reproductive organs or in the older stages of the fungus.^ In higher fungi, septation begins with the first appearance of mycelium and extends acropetally, growth in length proceeding from the terminal cell. Sexual organs are without doubt present in the lower fungi, but amongst the higher forms, lirefeld believes that the sexual act no longer exists. On the other hand, certain organs, found especially in the lichens, have been regarded as sexual. Dangeard regards the union of cell-nuclei as a sexual act, and assumes its existence in the asci and basidia of higher fungi. His more recent investigations on the nuclei of fungi, com1)ined with those of Pairault and Raciborski, have laid the way to a new systematic arrangement.^ Just as amongst the lower fungi the cell produced by a sexual act contains a nucleus derived from the fusion of two nuclei of distinct origin, so amongst the higher fungi one also finds cell-nuclei derived from copulation. The investigations of Dangeard, Eosen, Wager, Pairault, and llaciborski, lead to the conclusion that : * "a stage may be found amongst higher, as well as lower fungi, in which two cell-nuclei of one cell copulate. The cells known as oospores of the Oomycctcs, zygospores of the Archimycctcs and Zyrjomiji-des, chlamydospores of the Ustilafjincac, and teleutospores of the 1 Smith, Disease of Lilies, 1888. -Zopf. Die Pilze, 1890; and Beitraqe z. Physiol, n. morphol. niederer Orf/aul-oncn, Heft III., 1893. ■'Dangeard. " Recherches sur la repro). The spores of the fungus are produced on the leaves of the broom. The characteristic features of a witches' broom are : that, without regard to the direction of the brancli on which it is borne, it is negatively geotropic in a marked degree, and endeavours to develop like a terminal leader slioot ; that the jioint of infection is distinctly conspicuous as the starting point of the broom. Sadebeck regards any twig-hypertrophy as a witches' broom, even that of Exoctscus Tosqimietii where there is no basal swelling and tlie twigs exhibit only very slight negative geotropism. The forms of witches' brooms are very varied. Amongst the best known are the hanging broom-like masses developed from buds of the leader shoots (c.f/. on cherry trees). As a result of the rich growth of twigs and their premature death, many of these brooms become tangled nest-like structures. The twigs in some are much elongated, in others shortened, in every case, however, they are abnormally numerous. As a rule the original leader shoot, on which some lateral bud has developed into a witches' broom, shrivels up and dies, its contents being, as it were, absorbed by the hypertrophied branches. r)ther general features have already been discussed in Part I. of this book. Smith^ found that the form of the witches' broom is not determined exclusively by the fungus. The perennating my- celium indeed gives the first impetus towards its formation, 1 Smith, loc. cit. K 146 ASCOMYCETES. but it is completed by the weight of the Inxjom itself, the excessive development of sleeping buds, and the premature death of twigs. Smith also investigated the anatomical changes occuring in witches' brooms due to Exoasceae. From his resumd we select the following : " In a witches' broom the increased thickness of the twigs and branches is due to a proportionally greater increase in the bark than in the wood, the hypoderm, especially, having its cells more numerous and larger, while their normal arrangement in longitudinal rows is lost. The cork-cells are enlarged and retain their plasma- content longer. The phelloderm is better developed. In the sclerenchyma-ring, the primary bundles of bast-fibres are smaller and further apart from each other, or they may be quite absent ; the bast-fibres are shorter and have thinner walls ; sclerenchymatous cells are more numerous, larger, and have thinner walls. The phloem is increased chiefly through enlarge- ment and increase in number of its medullary rays; phloem crystal-deposits tend to be multiplied. In the wood, the parts most enlarged are the pith and medullary rays ; tracheae are more numerous, but their component elements are shorter ; the wood-fibres have thinner walls, wider luniina, and are often chaml)ered ; the normal course of the long elements is much disturbed by the greatly enlarged medullary rays. Sadebeck has recently divided the parasitic Exoascau' into these genera : {a) Magnusiclla, with asci isolated on the ends of mycelial threads which lie between the epidermal cells ; in the other genera the asci arise from a subcuticular hymenium ; (&) Taphrina, without a perennating mycelium ; (<") Evonscvs, with a perennating mycelium ; (d) Tajyhrinojjsis may be taken as another genus. Ascomi/crs he does not reckon with the Exoasceac. Brefeld divido.s tlic faiuily into Kroascus, with eight spores in the ascus, and Taphrina, with four-spored asci. Sadebeck shows, however, that eight is the normal number of spores in all the species, and that variation therefrom is fn^iuciit, four or more sjwres or niimemus conidia being formed. Schroeter separates the genus Magnusiella, as Sadebeck has done, then divides the remainder into Exoascus with eight-sjiored asci at time of maturity, while those with many-spored asci are ])laced under Tapliria (the older name given to Taphrina) THE PARASITIC EXOASCEAE. 147 According to Sadebeck, the E-wasccac may be divided as follows : Exoascus. The mycelium perennates in the tissues of twig or bud. The subcuticular mycelium is developed from the perennating one, and becomes completely divided up, without any differentiation, into ascogenous pieces. The species are all parasites and produce hypertrophy of leaves, flowers, and shoots. A. The mycelium perennates in the inner tissues of the shoot. Thence, in the next vegetative period, it sends branches into the leaves in process of development, at first into the inner tissues, but later subcuticular for the formation of re- productive parts of the fungus. (1) Asci developed in the carpels, which in conse([uence become hypertrophied ; asci with a stalk-cell: E. jirnni Fuck. E. Rostrv/pianus Sad. E. amimv.nu Sad. E. Farlowii Sad. E. rhizipes Atk. E. lonfjipcs Atk. E. confnsus Atk. E. cecidomojjhilus Atk. (2) Asci developed only in the foliage leaves. (a) Asci with stalk-cell : E. insititiac Sad. E. ccra.si (Fuck.). E. nanus (Joh.). E. deformans (Berk.) E. dccipiens Atk. E. accrinvs Eliass. ill) Asci without stalk-cell: E. lyurpumsccns (Ell. and Ever.). E. aescidi (Ell. and Ever.). (3) Asci developed on leaves and fruits. («) Asci with stalk-cell : E. mirahilis Atk. H. The mycelium perennates in the buds of host-plants and issues thence in the next vegetative period to develop in young leaves, subcuticular only. (1) Asci only on the foliage leaves. {a) Asci with a stalk-cell : E. cratacfji (Fuck.). E. minor Sad. E. Tosquinetii (West.) E. epiphyllvs Sad. E. turgidus Sad. E. hetulinus (Eostr.). E. aljnnus (Joh.). (b) Asci without a stalk-cell : E. catpini Eostr. E. hadcri- ospermus (Joh.). E. Kruchii Vuill. (2) Asci on carpels; without stalk-cell: E. aim incanoc Kiihn. E. Joliansonii Sad. E. rhizo2)liorus (Joh.). (3) Mycelium grows intercellularly. E. cornu cervi Giesh. 148 ASCOMYCETKS. Taphrina. The whole mycelium is subcuticular and differentiated into one portion, which remains sterile, and into an ascogenous part. I'erennation of the mycelium does not occur. The species pro- duce spots or hypertrophy on leaves or carpels. A. The fertile hyphae are completely used up in the for- mation of the asci. (1) Asci with a stalk-cell: T. hitUata (Berk, and Br.). T. ostryae Mass. T. Sadehcckii Joh. T. aurca (Pers.) (may also occur without a stalk-cell). (2) Asci without a stalk-cell : T. jilicina Kostr. T. l)olijs.ixrr(i (Sorok.). T. carnca Joh. T. coerulcscens (Mont, and Desm.). T. virf/mim Seym, and Sad. T. extensa (Peck.). 13. The fertile hyphae are not completely used up ; asci with a stalk-cell : T. hdulac (Fuck.). T. idmi (Fuck.). T. cdtis Sad. Taphrinopsis. Mycelium and hymenium developed only inside the epidermal •cells. T. Laurencia Giesh. Mag-nusiella. The mycelium inhabits the inner tissues of living plants and is always parasitic. Asci are formed at the extremities of branches of the mycelium, either between the epidermal cells or between cells of the inner tissues. The asci contain more than four spores, which generally produce conidia inside the ascus. The species generally cause leaf-spots, more rarely they appear on stems. (a) Asci witliout a stalk-cell : M. potentillac (Farl.). J/, lid- csccns (Kostr.). M. /lava (Farl.). M. githaffinis (liostr.). J/. uriibelliferarum ( Posti. ) . (6) Asci with a stalk-cell : M. fasclralata Lag. et Sad. Giesenhagen {loc. cit.) comes to the conclusion that the species of the parasitic Exoasceae have developed from a common ancestor simultaneously with the species of the higher plants inhabited by them, and that the development of host and parasite THE PARASITIC EXOASCEAE. 149 has progressed side by side. He shows that Exoasceae, Hviiig on related hosts, agree so closely in their ascogenous forms, that it is evident they are generically related species. On this ground he sets up a genus containing many species, and names it Taphrina. According to the host-plants, this genus is divided into four stems, and from it twenty-five species are separated off as the genus Magnusidla. Giesenhagen's systematic division, gives a synopsis of the host-plants and their distri- bution as follows : I. Genus. Taphrina : asci club-shaped to cylindrical. A. Filices-&iQyi\, on Ferns : asci slender, club-shaped; tapering to both ends, rounded apex, greatest breadth in the upper quarter of the ascus. T. cor mi cervi (Giesh.) on Asjndivm arista f inn in East Indies and Polynesia. T. Jilicina (Rostr.) on Aspidium s2)inulosnvi in Scan- dinavia and ]>alkan-peninsula. T. Laurencia (Giesh.) on Ftcris quadriaurita in Ceylon. T. fasciculata (Lag. et Sad.) on Ncphrodivm in South America. T. lutcsccns (Kostr.) on Aspidicm T/uiijpfrris in Denmark. B. Fctula-stein on Jidifforac: asci plump, cylindrical, with rounded apex or even a slight depression there. (1) On Ulmaceae : T. ulmi (Johan.) on Uhmis montaua and U. campestris in Central Europe and North America. T. cdtis (Sad.) on Celtis australis in North Italy and Switzerland. (2) On Bdvlaceac. («) On Betv.la : T. alpina (Johan.) on JJ. nana in Scandinavia. T. imim (Johan.) on B. nana in Scandinavia. T. behUae (Johan.) on B. vernicosa, B. puhcsccns, and IJ. turkestanica in Central Europe. T. Ictidina (Eostr.) on B. imhcsccns, and />'. odorotn in Germany, Denmark, and Scandinavia. T. carnea (Johan.) on B. odorata, B. imhciiccns, B. nana, B. intermedia in Scandinavia, Tyrol, and Silesia. T. bacieriospermmn (Johan.) on B. nana in Scandinavia and Greenland. 150 ASCOMYCETES. T. Jlava (Farl.) on B. populifcra and B. papyracca in North America. T. turgida (Sad.) on B. verrucosa in Germany and Tyrol. (b) On AlniLs: T. cpiplii//la (Sad.) on A. incana in Europe. T. Sadehcchii (Johan.) on A. glutiiiosa in Europe. T. Bobinsoniana (Giesh.) on A. incana in U.S. America. T. Tosquinetii (Magn.) on A. ghitinma in Europe. T. alni incanae (Magn.) on A. incana in Europe. (T. cdni glutinosae (Tubeuf) on A. glutinosa in Italy, Sweden, and Denmark.) {c) On Ciipidifcrac: T. ostryac (Mass.) on Odrya carpinifolia, in Tyrol and Italy. T. virginica (Sey. et Sad.) on Ostrija virginica in North America. T. carpini (Rostr.) on Carpinus Betidus in Europe. T. austrcdis (Atk.) on Cajpiniis americana in North America. T. Kruchii (Vuill.) on Quercus Ilex in Italy and France. T. coerulescens (Tul.) on Quercus scssiliflora, Q. pedun- culata, Q. p)ubesccns, Q. alba, etc., in Europe and America. ((/) On Salicaccae : T. aurea (Fries.) on Populus nigra, P. pgramidalis and F. monilifcra in Europe and North America. T. Johansonii (Sad.) on Populus trcmula, P. trcmuloidcs, and P. grandidcntata in Europe and North America. T. rhizophora (Johan.) on Populus alba in Europe. €. Prunus-stem on Rosaecae : asci slender and club shaped. (a) On Pomaceae : T. cratacgi (Sad.) on Cndaegus Oxycantlia in Europe. T. bullcda (Tul.) on Pyrus communis and Cydonia ja'ponica in Europe. {}>) On Pruneae : T. deformans (Tul.) on Persica vulgaris aiid Amygdalus communis in Europe and North America. T. minor (Sad.) on Prunus Chamaecerasus near Hamburg and Munich, THE PARASITIC KXOASCEAE. 151 T. liisititiac (Johan.) (jii Pramis Imititia and F. domestica, in Europe, and P. pcnnsi/lvanica in North America. 7\ dccijncns (Atk.) on Prunus amrricana in North America. 7\ ccrasi (Sad.) on Prunus Cerasus and P. Chamacccrrmis, in Europe, and P. avium in North America T. 2)7'uni (Tul.) on Prunus domestica and P. Padi/x in Europe and North America. T. mirahilis (Atk.) on Prunus ancjustifolia, P. liorfuJana and P. americana in North America. T. Farloivii (Sad.) on Prunus serotina in North America. T. confusa (Atk.) on Pmnus virginiana in North America. T PuMrwpiana (Sad.) on Primus sjnnosa in Europe. T. communis (Sad.) on Prunus maritima, P. pumila, P. americana and P. nigra in North America. T. longipes (Atk.) on Pimnus americana in North America. T. rhizi'pes (Atk.) on Primus trijlora in North America. (c) On Potcniillcae : T. potentillac (Johan.) on P. sijlvcstris, P. c(in<(d(iisis, and P. gco'idcs in Europe and North America. D. Aesciilus-Qtem on Eucyclicac : asci phim]), cylindrical, witli at or rounded apex. {a) On Sapindaceac : T. acsculi (Ell. et Ever.) on Aesculm californica in California. (&) On Anacardiaccac : T. purpurascens (Robins.) on Rhus cop(dlina in North America. {c) On Acerincac : T. acericola (Mass.) on A. campestrc and A. Pscndojilatdnns in Italy. T. accrina (Eliass.) on A. jilatanoidcs in Sweden. T.pohjspora (Johan.) on A. tartaricum in Europe. IT. Genus. Magnusiella : asci ovoid or spheroidal. M. githaginis (Sad.) on Agrostemma Githago in Denmark. 31. umhclliferarum (Sad.) on Hcracleum Spho/ulglitim, Peucedcmum palustre, and P. Oreoselinum in Europe. 152 ASCOJIYCKTES. The E.coasccac may be groupetl, according to the symptoms of the disease produced, as follows ; for this purpose we shall class all the species as one genus, ' Exoaseus' (or Taphriva): I. Species which cause deformation of the ovary or other part of tlie fruit. E. pritni (Fuclc.) on I'nnii/.s dumcsfica, 1\ Padui^, 1\ vir- giniana. E. RostrupianKti (vSad.) on Primus spinosa. E. communis (Sad.) on Pnmus 2')umilla, P. maritima, P. nigra, P. americana. E. Farlowii (Sad.) {E. varius, Atk.) on Prunus scrotiiia, causing also deformation of twigs. E. longipes (Atk.) on Prunus americana. E. confusus (Atk.) on Prunus virginiana. E. o^hizipes (Atk.) on Prunus trifiora. E. cecidomophilus (Atk.) on insect-galls on the fruits of Prunus virginiana. E. mirabilis (Atk.) on Prunus angvstifoiia, 1\ liortulana, P. americana. [Also species on Prunus suhcordata, P. Chicasa, and P. pennsylvanica.'] E. alni incan/ie (Kiihn) (E. amcnt.orvrn, Sad.) on Alnus incana. E. alni glutinosae (Tubeufj on Alnus glutinosa. E. Robinsonianus (Giesh.) on Alnus incana. E. Johansonii (Sad.) on Populus trnnula, /'. h'cnudoidfs, ]\ grandidentafa. E. rhizojylwrus (Johan.) on Populus (dha. II. Species whicli (1) produce witches' brooms, or (2) at least cause deformation of shoots ; asci produced on the leaves. (1) E. cpiphyllus (Sad.) {E. horcalis, Johan.) on Alnus incana (uniform grey coating of asci on l)oth sides of leaf.) E. turgidus (Sad.) on Bdula verrucosa (coating of asci on under surface accompanied by slight crumpling of leaf). E. hetidinus (Kostr.) on Bctula pudtesccns and B. odorata (coating of asci on under surface). THK rARASITIC EXOASCEAE. 15;^ E. (dpiuvs (Johan.) on Bctvla nana (coating on under surface). E. carpini (liostr.) on Caiyinvs Bctnlvs (coating on under side, and crumpling of leaf). E. cerasi (Fuck.) on Frunus Cerasv.s and F. arium (coating, chiefly on under side, and crumpling of leaf). E. indtitiae (Sad.) on Frunus Lisititia, F. domcstica, F. jicnnsylvanica, (F. spinosa ?) ; (coating on under side, and crumpling of leaf). E. acerimis (Eliass.^) on Acer plainnoidrH ; (asci on Iniih surfaces). E. acHCidi (E\\. et Ever.) on Arftridus raJifornica ; (coating on. both sides). E. Krvcliii (Vuill.) on Quevovi^ Ilv.r. E. rorni', cervi (Giesh.) on Asjndium aristatvin. E. Laurencia (Giesh.) on Fteris quadriavrita (with deforma- tion of leaves). (2) E. nam's (Johan.) on Bctvda nana (white coating on upper side). E. hactcriosprrnivs (Johan.) on Bchda nana (coating on both sides). E. dccipicns (Atk.) on Frunv.s amcricana (coating on both sides). E. parpurasccns (Ell. et Ever.) on Rhns aij^dlina (crum- pling and red-colouration). E. Tosqidnp.tii (West.) on Alnus f/lnfinosa and A. f/lnf. x incana (large blisters and elongation of shoots). E. pruni (Fuck.) on Frunus domcstiea (blistering and crum- pling). E. minor (Sad.) on Frunvs C/annaecerasns. E. deformans J5erk. on Fcrsica vulrjaris and Ann/{/didi's communis (blistering and crumpling). E. cratacgi (Fuck.) on Cratimjvs Q.nidcantlia (spots and blisters on the leaves). E. mirabilis (Atk.) on Frunus angustifolia, F. hnrhdana, F. amcricana (on twugs, leaves, and fruits). E. ccltis (Sad.) on Celtis austrcdis (brown spots). E. gitliaginis (Eostr.) on Agrostcmma Githago. ^SveiU-a J'et.-Akad. Handl. 20, 1895. 154 ASCOMYCETES. III. Species which produce (1) pustule-like outgrowths, (2) leaf-spot, or (3) smooth coatings of asci. E. aureus (Pers.) on Populus nigra (incl. jii/ramidalis) and P. monilifcra. E. polysporus (Sor.) on Acer ta.rtaricum and A. Pscudo- 2datanus. E. hullatus (Berk, et Br.) on Pyrus communis and Ct/donia Japonica. E. carneus (Johan.) on Betula nana, B. odorata, and B. intermedia. E. coerulescens (Desm. et Mont.) on Qurreus pvhesccns, Q. sessilifiora, Q. Ccrris, Q. laurifolia, Q. ruhra, Q. tinctoria, Q. aqnatica. E. Sadebeckii (Johan.) on Alnus glutinosa. E. ulmi (Fuck.) on Ulmus campestris, U. monta/iia, and U. americana (spots and blisters). E. virginicus (Sey. et Sad.) on Ostrya virginica. E. australis (Atk.) on Carpinus americanus. E. filicinus (Eostr.) on Aspidium spinulosum. E. potent iliac (Farl.) on Potentilla gco'idcs, P. canadensis, P. sylvestris. E. githaginis (Rostr.) on Agrostemma Githago. E. lutcscens (Eostr.) on Polystichiim Tlielypteris. E. miibellifcrarum' (Eostr.) on Heraclcum Sphondyliiim, Pcu- cedanum pialustrc and P. Oreosclinum,. E. ostryac (Mass.) on Ostrya carpinifolia (brown spots). E. betulae (Fuck.) on Bctida vrrrncosa, B. jiuhescnis, B. titrkestanica. (whitish spots). E. Jlavus (Farl.) on Betida popidifolia, B. papyracea. E. acericolus (Mass.) on Acer campestre and A. Pscudo- platanus. E. fasciculatus (Lag. et Sad.) on Nephrodium (whitish spots). The following are some of the more important species of Exoasceae : Exoascus pruni Fuck. (Pocket-plums). This attacks the ovaries of Prunn.s domcstica (plum), P. Padus (bird cherry), and P. virginiana, causing the mesocarp to grow rapidly, whereby the fruits increase in size and become much changed in form. THE PARASITIC EXOASCEAE. 155 wliile the stone, including the embryo, remains stunted. (Fig, 49.) The "pocket-plums" (fools or bladder-plums) dry up, and remain hanging on the tree till autumn. De Bary found on the plum a withering of calyx and stamens resulting from the development of the hymenium of this Ejxxiscu^ ; on the bird cherry, according to Magnus and Wakker, enlargement of tlie stamens occurs. Sometimes a considerable thickening and twisting of the young shoots takes place, and their leaves curl up. Fig. iS.—Exoascv.a pruni. Twig of Plum, with four deformed fruits; one normal plum is partially hidden, the other is in the middle. ^ natural size, (v. Tubeuf del.) The mycelium hibernates in the soft bast of the twigs, and proceeds thence in spring into young shoots and ovaries. According to De Bary, the infected ovaries double their size in two days, and are full grown in eight days. The asci form a close layer under the cuticle of the ovary, and finally rupture it. 15G ASCOMYCETES. Exoascus Rostrupianus Sad. This fungus causes " pockets " on J'ri'ni's sjiinosti (sloe) similar to the preceding species. According- to Sadel)eck, the asci in this case are more slender. Fio. 49. — Exoascus pruni. Malformed Plums — "pocket plums"; one which is cut shows the rudimentary stone. * natural si/.e. (v. Tubeuf phot.) Fio. 50. — Exoascus pruni on twig of Pr Padus (at end of July). Four of the ov are malformed, (v. Tubeuf del.) Fio. 51. — Exoaxcus prmii. Young twigs of Plum, showing effects of mycelium. The shoots are swollen and distorted, one diseased leaf remains hypertrophied and much crumpled; on one spur a normal and a "pocket" plum are borne. Specimens from the Museum at Geisenheim. J natural size. (v. Tubeuf phot.) THE PAKASITKJ EXOASCEAE. 157 Exoascus communis Sad. This produces pocket-plmiis on I'm HUH (/ineriaoix, P. pamila, and P. maritima in America. Similar " pockets " also occur on Primus subcordata, P. Chicasa, and P. jminsylvaiiim, in America, as a result of some Broascus. Exoascus Farlowii Sad. produces similar deformation of carpels and floral envelopes on Primus serotina in North America. Exoascus Johansonii Sad. produces carpel- eidargement on the female catkins of Populus tirmula, P. tremidoidcs and P. (jirmdidetitata; the contents of the asci are yellow. (Fig. 52.) The anatomy of the deformed ovaries has just been described by Sadebeck.^ Exoascus rhizophorus Johan. causes similar fw. bi.-Exoaicus ,.,,., 1 . f Ti 7 Johansonii Sad. on enlargement ot the icmale catkins oi Po/Jiilus Popuiv.stremv.ia. (v. ,, ■* Tubeufdel.) (dl)ii. Exoascus alni-incanae Ktihn {Ex. amentorum Sad.) This species is readily distinguished by the absence of a stalk-cell on the ascus. It causes increased growth and enlargement of the seed-scales of alder catkins, the fruit itself being seldom attacked. The fleshy bladder-like outgrowths at first appear as little red processes ; later, the asci are developed on the outer surface as a whitish coating. On many of these red processes may still be recognized the trifid apex of the normal .scale, (this is really formed from five smaller scales fused into a single large one with a trifid apex). A number of these red outgrowths are generally present on each infected catkin, yet the alders continue to flower vigorously every year. Wakker,- in investigating the anatomy of the deformed scales, found the following alterations : — the scales are increased to many times their original size and contain two cavities; all parenchy- matous cells become regular and iso-diametric ; lignification of the elements of the wood is more or less interfered with, and fewer wood-fibres are produced ; there is an accumulation of transitory starch. Exoascus alni-glutinosae Tubeuf. This is a new species distinguished by v. Tubeuf iu 1895. It occurs in the Sudetic mountains, Italy, Denmark, and Sweden, on Alnus rjlutinosa. Its habit is similar to that of Ex. alni-incanae, but the asci ^ Sadebeck (See Literature), 4. p. 144. - Prinrjiheim'-i Jahrhnch, 1892. 158 ASCOMYCETES. contain only conidia, whereas those on Alnus-incana are said by Sadebeck to contain only ascospores, unless on very rare occasions. In the lower and higher Alps, although both species of alder are not infrequently found together, yet the Exoasms is found only on Alnus incana, and no species occurs on A. glvtinosa. Fig. b'i.—Exoasoia alni-incanae in catkins of Alnus incana. Many of the scales arc developed as elongated red soft tongue-like structures, on which the asci arc produced as a whitish coating, (v. Tubeuf phot.) Exoascus epiphyllus .Sad. (Ev. horcalis Joh.^) The witches'- brooni fungus of the white alder {Alnus incana.) The author- was the first to describe and figure this form of disease in 1884; and Sadebeck recently succeeded in pro- ^ K. Sven. Vet. Akad. 1885 and 1887. Tubeuf, Botan. Centralbl., 1890. -Tubeuf, Beitriige ?.. Kenntniss d. Baumkranlhdttn, 1888. THE PARASITIC EXOASCEAE. 159 duciiig the brooms by artificial infection of alder. The disease is common and epidemic, and a single tree may carry as many as a hundred brooms. The witches' brooms are composed of many thickened twigs, beset with an abnor- mal number of lenticels, and the point of infection shows a distinct swelling, from which the broom tends to turn directly upwards. The leaves are somewhat modified, they are larger and thicker than the normal, they unfold later and wither earlier, while their stipules remain attached for some time. The brooms of alder only survive a few years, and by their decay cause the death of large branches, and frequently of the whole tree. The asci, which are sunk in a depression of tlieir stalk-cell, form a white coating on both surfaces of the leaves. The mycelium hil)ernates in the l:)uds. Exoascus turgidus Sad. causes- the formation of witches' brooms on Bdvla verrucosa. The leaves form- ed on the brooms are some- what crumpled, and the asci are produced on their lower surface. Exoascus betulinus Eostr. produces witches' brooms on Bdula puhescais and B. odorata. epiphytlits. broom in first year, shovving swelling at the point of infec- tion. The leaves are already shed in autumn, while the normal still remain 4 natural .size. After V. Tubeiif.) 160 ASCOMYCETES. * Witches' brooms on birch are very coninion in Scutlantl. They appear as tangled masses of twigs, whieli at lirst sight give the impression of some bird's nest. 1 have fre([uently examined the leaves borne on these brooms, and have never failed to find the asci of an Exoascus. Sadebeck gives in his monograph the two above-named species as found on birches bearing witches' brooms. Mites {e.g. Phytojjtus) have also been given as the cause of these malformations. On close examination of brooms which undoubtedly bore Exoascm, I found that a broom results from a prolitic development of small twigs on one or a few knotty swollen parts of a l^ranch. Each central ^—. . i ^^, j^r^fi*'' ^ Via. j5. — H'il'-ii. s ll.-ni,,,, ,,i I ', Ilnriihai-iit. Rroascas rar/iiiii on CarpiHw: B' lulus. The bush tne;is\ircs ;ibuiit 1 niftif :icross, and arises hiterally from a branch, the upper normal part of which has been removed, (v. Tubeuf pliot.) knot we may regard as the position of the bud which was first infected, and from which the broom system took its origin. As one result of the attack of the fungus, the greater number of the buds in the axils of the scales of the infected bud have grown out as twigs, but not into well-developed ones. In consequence, nearly every twig has been killed back by the winter, but not completely, so that from each twig- ])ase has sprung a new crop of stunted immature twigs like the first, and equally liable to be killed in the following winter. Thus has arisen that tangled mass of dead or sickly birch twigs which we call a witches' broom. [Edit.] THE PARASITIC EXOASCEAE. 161 Exoascus alpinus -lohan. and Ex. nanus Johan. Both occur on Biiidii iKnui, and induce formation of hypertrophied twi^s. Fig. 56.— Witcha' Broom of the Cheny. Exoascus cerasi on Prunus Cenmus. The whole left side forms a large broom. A smaller example occupies the summit of the crown, while another hangs do^^^lwards to the right. In winter condition, (v. Tubeuf phot.) The mycelium of Re. nanus hibernates in twigs, and penetrates L 162 ASCOMYCETES. into the inner tissues of newly-formed twigs and leaves. The mycelium of Ex. alpinus passes the winter in the buds,|^spreading thence in spring into young twigs and leaves. il/^' I'M f,' ■• . - ^./ -^A4^* ti \^' 'k' -'-^l.^ l^^ ii^r '^^'- V^'^'X* Fig. 57.— £'.coa3Ci/.s ccmsi on Pt-unws Cerasas. Cherry-tree in blossom, with the exception of four witches' brooms. The tree is as yet leafless except the brooms, which are in full foliage and show up dark. (v. 'I'ubeuf phot.J Exoascus carpini liostr. is common on Carpinus Betulus (horii- heam) (Fig. 55). The brooms produced are bushy and densely leafed ; the twigs are thickened and much branched ; the leaves THE PARASITIC EXOASCEAE. 103 are somewhat curled up, and the asci a[)pear on their lower surface.! Exoascus cerasi Fuck, occurs very commonly on cherry trees (Fninus Ccrasus and P. avium) both in Europe and America.- It produces witches' brooms, which may be large, upwardly directed, bush-like, and very conspicuous structures, witli numerous thickened and elongated twigs (Fig. :3); or they may be small, hanging bunches of twigs with upturned free ends. The leaves are somewhat wavy, slightly crumpled, and reddish ; on their lower epidermis they bear asci, and fall otf pi'i'iuaturely. , as in Fig. The brooms are visible at a considerable distance in the winter (Fig. oQ), while they are even more conspicuous during the lowering season (Fig. 57). At the latter time, before the leaf-buds open, the cherry trees are normally covered with white blossom, while the brooms bear leaves only, and rarely blossom. Hence they produce little or no fniit. P^ach tree ' Wehmer (Bot. Zeituwj 1896) discusses the formation of these witches' brooms. (Edit.) - E. Rathay, " Uber die Hexenbesen d. Kirschbiiumen."— 5(7;«HrMf>*. 'Z. A'- K. Akad. zii Witn, 1881. 164 ASOOMYCETES. may bear several bruuins, and every tree in a fruit-garden may be attacked, so that this disease has assumed consider- able economic importance. As a preventive measure, the remo^'al of all brooms at the time of pruning the trees is strongly recommended. [According to Shirai (Tokio Jititcmical magazine, 1895) witches' brooms are produced in Ja})an on Primus i^scvdo-ccrasvs, by a distinct species, Ex. ^«r;/^(>- ccra^us.'l Exoascus minor iSad. This species induces hypertrophy of shoots of Prunus Chamaccrra.Kns and P. Ccrasi's, but cannot be said to cause formation of witches' brooms. The mycelium hibernates in the buds, autl spreads only underneath the cuticle, while that of Mr. cor/si lives in the tissue of the twigs and leaves. It is characteristic of this species that only leaves here and there on a twig may Fig. 5!).-Twig from witches' broom in bc attacked, whilc tlicir ncigll- foliage, as in Fig. 67. Pliotographed at same . ' time as Fig. .OS for comparison, (v. Tubeuf bours remain quitc healthy; both flowers and fruit may also be borne. Diseased leaves appear much crumpled, and Sadebeck states they have an odour of cumarin ; they turn brown |)re- maturely and fall off. Exoascus insititiae Sad. is found on Prunvs domcstica and P. Insititia in Europe, and P. 2J<^nnsylvanica in North America. Tt causes formation of witches' brooms smaller than those on the cherry tree, yet probably more common in the fruit garden. They bear no fruit, and are a source of considerable loss. The mycelium hibernates, like that of Ex. ccrasi, in the Itark of twigs, and spreads in spring into the buds. The leaves of the host bear asci on the lower epidermis ; they are always more or less curled up, and fall off early. To prune off all brooms is the best preventive measure. THE rAKASITIO EXOASCEAE. 165 Exoascus deformans (]')erk.) causes the " curl disease " of tli peach {Persica vvlrjaris), and may inflict great injury. Th Cuil disease of Cherry. mycelium hibernates in bark, pith, and medullary rays of so that it reappears each year. An B.ax/scn^, which twigs, (jccurs Fig. {il.~-£j:oascus dejormans. Comparison of normal section of leaf of P,vnu> Persica with a hypertrophied one, B; in the latter the mycelial hyphae liave been slightly shaded. The sections are from different parts of tlie same leaf, and are drawn with the same magnification. (After W. G. Smith.) Oil the almond {Amijgdalus communis), resembles Ej^. deformans so closely that they are now regarded as the same species. 166 ASt'OMYCKTES. This is supported by Smith's investigations, in which an an- atomical comparison of diseased twigs of peach and ahuoiid showed no difference in the pathological effects. Exoascus crataegi Fuck, occurs on Crataegus Oxyavantha , and causes red swellings on the leaves and flowers, accom- panied l)y hypertrophy of shoots in which the mycelium perennates. Exoascus Tosquinetii (West.). The deformation caused by this species is frequent on the black alder (Alnv.s glutinosa). The thickened, elongated, wrinkled twigs render attacked parts very conspicuous in contrast to the normally developed parts of the tree. The leaves may l)e wholly attacked and much enlarged, or they may only be hypertrophied at places so as to form pustule-like swell- ings. The epidermal ami mesophyll- cells of diseased leaves become greatly en- larged. Exoascus aureus (Pers.). The leaves of the black poplar (Pojn'/vs iiigra) attacked by this parasite exhibit pustides (Fig. 62). The asci are formed as a golden coating fin the concave side of the ])ustules, which is, in most cases, the under side of the leaf, rarely the upper. The cells forming the pustules have thicker walls and a somewhat different shape from the normal epidermal cells, and they are not unfrequently sub-divided by walls of secondary origin (Fig. 63). According to .Smith, the cells of the palisade parenchyma have also thickened walls, as well as behig elongated and occasionally chambered ; the cells of the spongy parenchyma are enlarged and have thicker walls ; so also are the cells of the collenchyma of the leaf venation. Leaf of Po'iiut-us Fui. C'i. — h'joannis o; niyru, showinp the ptistulc-like swellings.' Tnbeiif del.) THE J'AHASITIC EXOASCEAE. 167 Exoascus coerulescens (Mont, et Desm.) produces similai blisters on oak leaves. Fici. 6'i.—Ej:o((scv.s aurevs. Leaf section from the margin of a swelling, showing normal and hypertrophied tissue. The cells of the swelling are alniomially elongated with thickened walls, and some show secondary cell-division. The bases of the asci are wedged in between the cells; one ascus is shown with conidia. (v. Tubeiif del.) Exoascus cameus Johan. occurs on leaves of Betula o'loralu, B. ndua, and B. intermedia. The pustular outgrowths rise above nevs on Bitt'lo. odomto. (v. Tubciif del.) Fio. 6u.— Section of nonual leaf of Betula odoratn. (After W. G. Smith.) Fn^. 00.- Section of leaf hypertrophied by attack of Exooncus cameus; the asci of the fungus coat the upper epidermi.s. Dmwn with the same magnification as Fig. 6-0, for comparison. (After W. G. Smith.) 168 ASCOMYCETES. the upper surface of the leaf (Fig. 64), and the upper epidermis alone bears the asci. In the pustules, the leaf may be two to four times as thick as healthy parts. The greatly increased thickness is due for tlie most part to enlargement of the cells of tlie mesophyll, while at the same time their normal arrangement is completely lost (Figs. Q5, 66). The elements of the libro- vascular bundles are enlarged ; the cells of the upper epidermis are more nmnerous, contain a reddish sap, and their walls are thickened. All cldorophyll is destroyed in the pustules. Ex. polysporus (Sor.) causes swollen spots on leuA^es of Ace7' tartaricum. Ex. buUatus (Fuck.) causes similar '^ spots on leaves of pear {Fyrus ^^ communis) and quince {Cydonia \_ jcifponica). [, Ex. Sadebeckii (Johan.) causes simple spots on leaves of Alnns i/hifiiw-'^a. Many other species, named in our list and in Sad check's papers, will be found described in detail in one or other of the papers already cited. K rm-.? Fici. Ii~ .— Exoaicm poli/sporus on Ac(r tartaricum from Sweden. The attacked leaf Hhows pule spots with brown centres. The former result frmii the To/>ltriita, and .ire covered liy a white coating; of asci ; the brown Mjiots are produced by other fungi which grow on the spots already killed. I nat. .size. (v. Tubeuf del.) Jl Carpoasci. {Ascomycetes loith SporocurjL/s.) The asci of the Carpoasci. are not formed directly on the mycelium, but from a special part of it, which becomes more or less enclosed in another non-ascogenous portion. From these two portions of the mycelium a sporocarp is formed, in which we can distinguish three distinct constituents: (a) the envelope containing (b) the paraphyses and (c) the asci. Amongst the Gyranoasci the envelope, if present, is never more than a loose hyphal tissue, but in the Carpoasci both paraphyses and envelope are present, the latter with char-, acteristics distinctive of each species. The sporocarps of the lower Carpoasci are completely closed structures containing only one or a few asci; those of the higher forms, however, (JARPOASCI. 169 contain many asci, and the envelope is jneiced by a detinite aperture. Brefeld endeavours to explain the ascocarp of the Eiysipheae from the sporangial structures of the Zyt,'osporeae {lihizopus and Mortierella); l)e Hary' and Zopf,- on the other hand, see in it an oosporangium, like that i)haerolhijca i>annosa on Pcaoh. Thu myccliiun and conidiophores are shown on the epidermis of a leaf. (After 'I'ulasno.) K'ose-mildew is propagated during summer by ovoid, uni- cellular conidia abjointed in acropetal series from erect conidio- phores. The perithecia have short simple appendages, and contain elliptical spores. The disease may be combated by "sulphuring"; according to i:itzema-Bos, spraying with Bordeaux mixture has also shown good results. Sl'HAEROTHECA. 173 Sphaerotheca (Podosphaera) castagnei Lev. (Britain aiul U.S. America). The Hop-mildew. The mycelium is found on all parts of hop-plants, causing considerable damage, especially when it attacks the young inflorescences. The perithecia have recumbent, brown, simple appendages. This species appears chiefly on various Compositae, Eosaceae (esp. Spiraea Uhnoria), (,'ucurbitaceae, Geraniaceae, etc. Sorauer reports it as very injurious to apple-trees. Fio. 70. — ajthaerothtca cusUiai lul ou Spinua L'iiiuina. The white luycelial coatiuy covers every part of the inflorescences. Two specimens are much less deformed than the others, (v. Tubeuf phot.) Oidium farinosum Cooke. Attacks young leaves and calyx of apple; it is easily distinguisiied from the oidium-condition of the preceding species.^ Sph. mors-uvae B. et C. The Gooseberry-mildew. Is specially injurious to IliJtcs Uva cvispa and other species of liihca in America. Spraying with a solution of potassium sulphide {I oz. in 1 gallon water) at intervals of twenty days is recommended.- ' Sorauer, Hedtcu/ia, 1889. -Halsted (U.S. Deparlmtnt of A(jricidlure, Report for 1887) describes this (Edit.). 74 ASCOMYCETES. Sph. epilobii l.k. Sph. Niesslii Tliii Sph. pruinosa ( '. L-uis on E/nloJninn (t-.S. Aiueiica). on Sin-bu.'i {Pi/rtiK:) Aria. l'l<. on /i/<».s in America. 9QQad6 Fio. 71. — Spkaci-otkeca castagnei. Epiphytic mycelium on epidermis of Spiraea Ulmaria. Three haustoria are embedded in epidermal cells. Two conidiophores are shown, from one of which a conidium has become detached. A hair of Spimea is shown at one side. (v. Tubeuf del.) Podosphaera. This genus is distinguished from Spluu: rotheca by its upriglit perithecial appendages, which branch dichotomously towards their extremities. Podosphaera oxyacanthae J). C. Apple powdery mildew, also ocruriing on pear (/'//r//.s), hawthorn {Crataegus), mountain cish (Pi/ras Aaciiparia), and medlar (Mesjnhts). In America this disease is very injurious to apple-cultivation.^ It attacks rhit'Hy young seedling plants, stunting tlieir growth and causing them to lose their leaves. P. tridactyla Wallr. This causes injury to leaves of various species of rni/ias (cherry, plum, and sloe)^ (Britain and U.S. America). -Account by M. B. Waite (U.S. Department of Arjriculture, Report for 1888); notes on treatment in Fairchild's experiments {Journal of Mycolofjy, \IU p. 2.56), and elsewliere (Edit.). 3 Halsted Zei/ichrift f. Pflanzenkrankheiten, 1895, p. 338) gives as additional hosts: Apple, Crataegus Oxyacantha, Amelanchier canadensis and Spiraea (Edit.). I I'ODOSPHAERA. P. myrtillina Schub. on leaves of Vaccinium Mjp'tillm (bil- berry), V. aliijiiwsuin, and Evrpdrnm nifjrinn (crowberry), (U.S. America). Erysiphe. The perithecia contain several asci, each with two to eij^ht oval hyaline spores. The appendages are like these of Sji/ikh- rotliccit, simple and thread-like. Erysiphe graminis D. C. Mould or mildew of grass and wheat. Grass and cereals, especially wheat, often suffer serious damage from this parasite. The mycelium appears on the leaves as white or brownish spots, generally on the upper surface. Colourless conidia (Oidiicm moniliuidcs, Lk.) are produced acro- petally in chains. The somewhat rare perithecia have brown appendages, and contain eight to sixteen asci, with four to eight spores each ; the spores mature in spring as the dead leaves lie on the ground. This mildew has inflicted great loss both in Europe and America. ])usting the threatened crop witli " flowers of sulphur " will proljably check the first stages of an attack, but care in destroying infected crops is by far the most effective prtiventive. Erysiphe martii Lev. This fre- ([uents various Leguminosae (clover, Ijeans, vetches, peas, lupines, etc.), Cruciferae, and other plants (Britain and U.S. America). Er. umbelliferarum De Bary. Occurs on various Umbelliferae (Britain). Er. communis Wallr. on tobacco, also on various Biinun- culaceae, rapilionaceae, etc. (Britain and U.S. America). Er. tortilis Wallr. on Cornus samjuinca (Britain and Aineriea). Er. galeopsidis D. C. on Labiatae (Ihitain and America). Er. cichoriacearum D. 0. on Compositae, Boragineae, also causing considerable damage to cucumbers (Britain U.S. America). '2. — Enjtiphe umheUiJc, Germination of a couidiuni («/>) on Anthriscui^ sylvestris. An attacli- ment-disc luis been foimed, and a c:emi-tube liivs penetr.ited t)ie epider- mis to become the first haustorium. (After De Bary.) .1 U.S. U.S. and and 176 ASCOAIYCKTES. Microsphaera. The perithecia contain several asei with two to eight spores, and the ai)iientlages have dichotoniously branelied ends like tliose of J\i]i)llliis ;iiid A. rinjntiis (Britain and U.S. America). M. berberidis D. C. on Barberry (Britain). M. lonicerae D. C on species of Lonicera. M. grossulariae Wallr. on Gooseberry (Britain and U.S. America). M. lycii Ijasfli. on Lycium, and Desmodium (Britain and U.S. America). M. evonymi J). ( '. un Evonyvius europaeus (Britain). M. alni D. C. on Almcs glutinosa, Betula verrucosa, and B. pubescenSy lUtaraMis cathartica, Vibvrnum Opvhis, and T'. La/ifana, etc. (Britain and U.S. America). M. densissima (Schwein.)^ Thi.s species forms orbicular patches on the leaves of (Inercus tinctoria, etc., in North America. M. Guarinonii Br. et Cav. on Cystisus Laburnun). Also several other American species. Uncinula. The perithecia contain several asci with two to eight spores. The appendages have involute ends, and are simple or dicho- tomously l^ranched. Uncinula spiralis B. and C- (U. S. America and Britain). Thi' \'iue ^lildew. This disease was first observed in England in 1845, and since then has spread over the whole of Europe. The conidial stage has caused widespread injury, but the perithecia remained quite unknown till 1892, when they were ob.served on vines in France by Couderc, and in 1893 in large numbers by Viala. In America, a similar disease is also well known ; its perithecia have been long recognized and named Unciinihi sjnralis. The identity of the American and European mildew was first suggested by Viala in 1887, and may now be assumed. The perithecia ^ when mature are brown, spherical, and beset with ^ Atkinson, Bidhlin of Torrey Botanical Club, Dec. 1894. - In consequence of recent investigations, this species has been transferred from the Kcnus Erysiphe, and revised with tlie author's consent. (Edit.). Viala, Coinpt. rend, cxix, 1894, p. 411. Prillieux, Bu//. de la Soc. mycol. de France, 1893. ^B. T. (Jalloway {Botanical Gazette, 1895, p. 486), gives a recent account of the development of this Uncinula. (Edit.). UNCINULA. 177 appendages liaviiig hooked tips. Within the peritheeia are found the ovoid asci containing the spores ; there are from four to ten asci in each peritheciuni, tind four to eight spores in each ascus. The conidial stage was formerly known as Oidiain Tnchri. The conidia are abjointed as oval colourless bodies from simple septate conidiophores, to the number of two or three in each chain. They germinate at once, and as they are formed in large numbers, especially in moist weather, the disease spreads rapidly. The mycelium is non-septate, or almost so, and attaches itself to the epidermal cells of vine-leaves and young grapes, by lobed attach- ment-discs, from which simple sac-like haustoria make their way Fio. '3.— l'ncinv./a aceris. Peritheeia. (After Tiilasne.) into the cells. The mycelium forms white spots, but after ;i time causes the death of cells near it, so that brown withered spots appear. The leaves generally wither, the grapes, however, continue to grow at the places not attacked, till rupture of the coat ensues, then they shrivel up or fall a prey to mould-fungi. Sulphur is the preventive generally used (See p. 170). Uncinula aceris D. C. (Britain). This appears as white spots on the leaves of species of Acer, native and cultivated. "When attacked by this mildew, young unfolding leaves are stunted in growth, while older leaves in autumn still retain their chloro- 178 ASCOMYCETES. phyll in diseased spots, so that when dead and yellow, they are still spotted with green. The conidia are oval, so also the spores of which six to eight are found in each ascus. U. Tulasnei Fuck, produces a white coating over the whole leaf-surface of Acer 2)lata7ioides. The conidia are spherical. U. circinata C. et Peck, is found on species of Acer in America. U. salicis D. C. (Britain and U.S. America). This species occurs on leaves of the willow, and produces white spots or thick coatings on one or both surfaces. It is also found on leaves of poplar and birch. U. prunastri D. C. on Prmius spinosa (Britain). U. Bivonae Lev. on Ulmus montana (U.S. America). Also other American species. ml ti 1 . luUsnt ) Phyllactinia. The spherical perithecia are flattened at the poles, and enclose several asci containing two or three oval sulphur-yellow spores. The appendages are sharp-pointed hairs with swollen bases. Phyllactinia suffulta Kebent. {I'lc. fjuttato Wallr.) produces white spots or coatings on the leaves of many trees, e.(j. beech, hornbeam, ash, birch, hazel, oak, etc. (Britain and U.S. America). b'lo. 76.--Phi/llacliiila suffulta on Fagtis sylvatica. The leaf is partially covered by a white mycelium, on which the perithecia appear as black points, (v. Tubeuf del.) PERISPORIEAE. The Perisporieae include the following genera Tliielavia, Dimc- rosporitcm, Mar/nusia, Cephalotheca, ZopficUa, Anixia, Eurotmm, PERISPORIEAE. 179 Aspergillus, Faiicilliam, Zopfia, Pcrisporiuin, Lasiobotrijs, Apio- sporium, Caimodiuvi, Astcrina, Microthyriuiifh. To this sub-division of the Perisporiaceae belong some com- mon forms of mould-fungi which are generally only saprophytic, Fio. l^.—PhyUactlnia suffulta from Beech. Perithecium, with characteristic appendages. Contents of the perithecium : asci, spores, and cliains of cells resembling paraphyses. (v. Tut>euf del.) but occasionally find their way into fruit with broken epidermis. They are thus found carrying on secondary decay and rot, where other diseases have begun the attack. 180 ASCOJIYfETES. In this group arc ineliulfd certain species of fungi which are ahle of themselves to induce rot in ripe fruit. Davaiue ^ waa the first to direct attention to these, and recently they have been made the subject of very searching investigations by Wehmer."^ According to this author, only a limited number of species of fungi accompany this kind of rot and give rise to it primarily. As a rule they effect an entrance by some wound, possilily also through lenticels or other apertures. Some forms prefer certain species of host-fruit, in some cases even certain varieties. Wehmer gives the following synopsis : FlU'IT. Apple, Pear, Medlar, Grape, Phini,- i \ Cause of Ripe-kot. Pemcillmm glaucum. Mucor piriformis. {Mucor stolonifer.) j Penicillium glaucum. yBotrytis cinerea. j Mucor racemosus. \ Pen icillium glaucum . Fruit. Orange, Citron, Mandarin, Cherry, - W aliiut. Cause ok Kii-e-uot. I Penicillium italicum, j Penicilliumolivaceum. ■ Penicillium glaucmn. (Botrytis cinerea. \ Penicillium glaucn m . He then arranges them according to their occurrence, beginning with the most frequent : Frnicillmm glaucum Link. : on stone-fruits, pome-fruits, grapes, walnuts, especially common on apples. Penicillmm italicum Wehmer : on southern fruits, e.g. citron, orange, mandarin. Mucor inriformis Fisch. : on pome-fruits, particularly on pears. Botrytis cinerea Pers. : on grapes and walnuts. The following are less common species : Penicillium, olivaceum A¥ehmer : on southern fruits. Mucor racemosus Fres. : on plums. Mucor stolonifer Ehrenl). : on apples. Iiipe fruit sliould be so treated as to remove risk of infection as much as possible. This is done by storing the fruits in airy, dry places, and in loose contact with each other. A damp atmosphere promotes infection and facilitates the progress of rot. All decaying fruit should be separated at once, and valuable fruits are best isolated by wrapping singly in tissue paper before transportation. ' Davaine, " Reclierches sur la pourriture des fruits et des vegetaux vivants," Compt. rend., Lxni., 1866. -Wehmer, Beilruge z. KenntnisH einhdmischer Pihe, Jena (Fischer), 1895. PERIsrclKIKAi:. 181 Species of fungi iiieliuled in this group are the cause of tliose black, sooty coatings found on leaves fre(|uented l)y green Hy {Aphis) and other leaf-insects. These are purely epiphytic and ■ saprophytic forms which derive nourishment from the "lioney-dew" excreted by the insects.^ They multiply very ra})i(lly, and soon form dark coatings on the upper side of leaves and twigs. Little damage need be feared, since the leaves retain their green colour, and the coating is not enough to stop access of light. Amongst them are species of Cap- iwdium, Meliola, and Apiosporium, as well as the conidial forms Fnriiago, Torula, Antcnnaria. The modes of reproduction of these forms are exceedingly varied. According to Zopf- they form: (1) ascocarps; (2) many- celled large conidia ; (o) unicellular, very small conidia ; (4) isolated and clustered conidiophores ; (5) gemmae; (6) buds in a yeast-like manner ; while every fragment of a mycelium can produce a new growth. Any of the species may frequent many various plants, and can pass easily from one host to another. Some of the better-known forms are : Capnodium salicinum ]\Iont. (liritain). This occurs on s[H'cies of willow, poplar, hop, and many other plants. If it appears early and abundant on hop it may cause considerable damage. {FamiKjo irif/f/ns is a conidial foim). C. quercinium Pers. on oak. (U.S. America.) C. taxi Sacc, et Roum. on Tr/nis. C. foedum Sacc. (spermogonium Horm = Chcdn/i/iovvi forda). On the leaves of oleander. (U.S. America.) The genus Apiosporium forms similar sooty coatings. A. pinophilum Fuck. This covers with a black coating whole twigs and leaves of silver fir; the needles however retain their green colour completely. (Aiifrnnaria and Torula are fcrms ..f this.) A. rhododendri Fuck. ; A. ulmi Fuck. ; and other species. Phe cDiiidial form Pellicularia which produces grey coatings on tlie coffee- jtlant is considered among the Hyphomycetes. Species of Meliola also produce sooty coatings. M. citri Sacc. and M. Penzigi Sacc. occur on Citnts in iBiisgen, Der Honhjthau. BioloijUcht Studkn an Pflanzen. .Jena (Fi.scher). -Zopf, "Die Conidienfruchte v. Funiago." Nova wtn, VA. 40. Also: Zopf, Dit Pilze; Tulasne, Select, fum/., tii. 182 ASC'OMVCKTKS. Suiitlicrn Europe and America. Sooty mould of the orange is also ascribed to Capnodium citri Berk, et Desm.^ M. camelliae Catt. on Camellia jainniicn. According to- Briosi and Cavara, this causes drying up of the leaves. Stemphylium ericoctomun Br. et Bary, tlie " sootv-ilew " of iiidoor lieatlis is con.sidereil amongst the Hypliomyeetes. Lasiobotrys. L. lonicerae Kunze.- The perithecia form black masses on green leaves of species of Lonicera. If these be removed the epidermis remains uninjured, except for a slight cavity with a lighter green colour than the neighl)0uring surface. Thielavia. Perithecia spherical and without an aperture. The asci contain eight brown unicellular spores. Paraphyses absent, Conidia and chlamydospores are formed. Thielavia basicola Zopf.^ This is the only species of the Perisporieae which causes a really serious plant-disease. It is allied to the Erysipheae, and produces three kinds of repro- ductive organs on the underground parts of plants of Lupine t (1) Cylindrical, delicate, hyaline chlamydospores, produced in pistol-shaped branches of the mycelium. (2) Thick-walled, brown-coated, resting conidia arranged several in a row, like spores of a Plira/jwidrnm. (3) Perithecia, or little, spherical,, permanently closed, brown structures with ovoid asci containing eight brownish lemon-shaped spores. A white coating of the hyaline conidia is first formed, then a brown coating of the dark conidia, and finally perithecia. The mycelium bores through the cell-walls and fills first the cells of the cortex, later those of the deeper parenchyma of the ho.st-root. The disease of the root soon causes a stunting of the shoots and leaves, finally death of the plant. The roots attacked are at first brown, then they rot and become detached, ' W. {}. Farlow, Bvll. Bimsey Inntihite, i. 1876, p. 404; Swingle and \Vt>))her, "Diseases of citrous fruits," U.S. Dejtt. Agric. Bull. 8. 1896. -Jaczewski includes Lasiobofry.s with the Citcnrbitariaceae. •'Zopf, " Ueher die Wurzelbriiune d. Lupinen." Ze.itschri/t f. Pfianzmkratik- heiten, i. p. 72. THIELAVIA. 183 The fungus has been observed on Lupinus anf/vstifolii's, L. alius, L. thermis, Trigonella cocridea, Onobrychis Crista galli, Pisvm sativum, Senecio elcgans, and Cj/elamcn} Thielaviopsis ethaceticus Went.- lias been given as the cause of a sugar-cane disease in Java. The Tuberaceae form a third sub-division of the Terisporiaceae. The group includes the Tubereae and the Elaphomycetes. It contains no forms injurious to plants. In investigating Elaphomyces fjranvlatus and E. rorictjatos, Reess ^ found that it not only formed mycorhiza, but was also parasitic on the roots of Pinvs and destroyed them. pyrenomy(;etes. The ascocarp or perithecium of the ryrenomycetes is a closed structure provided with an opening by which the ascospore.s are discharged. The ascocarp of the Perisporiaceae, as ha.s already been pointed out, has no such opening. The inner wall of the perithecium is clothed with (a) the asci, {h) delicate fungal filaments. Of the latter, those in the depth of the perithecium are known as paraphyses, and among them the asci originate ; others around the sides and opening of the perithecium are the periphyses, which grow inwards so as to close both pore and canal, Perithecia may occur isolated or massed together, and are frequently sunk in a special cushion of fungoid tissue, the stromata. The Pyrenomycetes may also produce chlamydospores and various forms of pycnoconidia and free conidia ; these also are frequently developed on special stromata. According to Brefeld's researches, the structures so well known as spermogonia with their contained spermatia are only pycnidia containing conidia, which have in many cases been artificially caused to germinate. The Pyrenomycetes include a large number of forms par- asitic on all parts of living plants, most of them are capable of existing for some ])art of their lives as saprophytes, and as 'This fungiis is described as causing a root-rot of Viola odorata in U.S. America [Connert. A, orifice of the perithecium. D, Isolated ascus ruptured, so that the thread-like asco- spores {sp) have begun to escape. (After Tulasne, from Sach's Lchrbvch.) hyphal tissue. In this condition they are introduced along with grain into bread, which when eaten acts as a powerful poison, producing very serious results (P>gotism). The sclerotia are also used medicinally, and are collected for this purpose (Sccale wriiutum). Robert (Frohner, Lehrhuch der Toxikologie fiir Thierartze, 1890) states that Ergot contains three poisonous agents : (1) Cornutiyi, an alkaloid which produces that particular effect of ergot in causing contraction of tlie uterus. (2) Sphacelic add, a non-nitrogenous, resinous, non-crystallizable sub- -stance, insoluble in water and dilute acids, but soluble in alcohol, and N 194 ASCOMYCETES. foniiing-, with alkalies, salts soluble in water. This is the real cause of ergot poisoning and gives rise to gangrene. In large doses it produces cramp similar to strychnine, and tetanus of the uterus. (3) Ergotic add, a nitrogenous, easily decomposed glycoside, which has no eifect on the uterus. It is more a narcotic which diminishes i'eflex excitability and tinally stops it. Robert experimented chiefly with cattle and fowls. He found that an acute course of the poisoning can be distinguished from a chronic ; also a gangrenous ergotism from a spasmodic. The symptoms of the disease are : (1) Gastro-enteric, an excessive salivation accompanied with redness, blistering, inflammation, wasting and gangrenization of the mouth-epithelium; similar changes also occur on the epitlielium of the gut, producing vomiting, colic, and diarrhoea. {•!) Gangrenization and mumniifica- ,. . tion of extremities, consisting of a j^^ j^ drying-up, a dying-off', and a detach- ment of extremities, such as nails, ears, tail, wings, claws, toes, and point of tongue. (3) Spasmodic contraction of the uterus and consequent abortion. (4) Nervous phenomena such as in- sensibility, blindness, paralysis, etc. The presence of ergot may be de- tected both microscopically and spec- troscojjically. The fungus may be combated by careful separation and de- struction of sclerotia, and by the use of clean seed.^ Claviceps microcephala (Wallr.) (liritain). This is found on Pliragmitcs, Molinia, Nardus, etc. It has smaller sclerotia, which, according to Hartwich,- on Molinia cotruiea. (v. Tubeuf phot.) conLaui turec iimes as mucu Ergotin as those of 6V. purpurea. 1 Smith {Diseases of field and garden crops. 1884. p. 233) describes and figures Claviceps purpzirea car. Wilsoni on Gtyceria fluitavs near Aberdeen. It is distinguished " in l)eing whitish or yellowish, instead of being pale piu'ple in colour, and in tlie peritheoia or conceptacles being almost free on an elongated club-like growth instead of being immersed in a globular head or stroma." -Hartwich, " Sclei'ote du Molinia eoerulea." Bidlef. cle la Soc. Myrolo;/. (Ic France. 1895. CLAVICEPS. 195 CI. nigricans (Tul.) on Hcleocharis and Scirpus, with sclcrotia of a dark violet colour (Britain). CI. setuloso (Quel.) on Poa. Stromata straw-yellow in colour. CI. pusilla Ces. on Andropogon Ischaemum. (2) SPHAERIACEAE. The group of the Sphaeriaceae includes eighteen families, but only the following contain parasites of interest to us. Families : Trichosphaei^ieae, Melanomeae, A^nphisphaerieae, Ciicuimtaruae, &plia&y^%deac, FUo^pdreae, Gnoinlmieac, Valsdic, Diaipfpeae, and Alelailemiideac. TRICHOSPHAERIEAE (including Coleroa and Herpotrichia). Coleroa. The perithecia have thin walls with radiating bristles, and sit superficially on the substratum. The asci have thickened apices, and contain eight two-celled, faintly coloured spores. Coleroa chaetomium Kunze, occurs on living leaves of Bid us cacsius and li. Idaeus. In addition to perithecia, it forms conidia known as Exosporium ruhi Nees. C. alchemillae Grev. (Britain and U.S. America). On leaves of Alclieinilld nilgaris. C. andromedae Rehm. On leaves of Andromeda ptolifolia. C. potentillae Fries (Britain and U.S. America). Leaves of Potentdla atiscrina. It forms perithecia which are situated on the leaf-ribs ; also conidia {Marsonia potentillae). C. subtilis Fuck. On leaves of Potentilla cinerea. C. circinans Fries. On leaves of Geranium rotundifolium and G. vw/lr. C. petasitidis Fuck. On leaves of Prtasites officinalis. Trichosphaeria. Perithecia small, spherical or ovoid, and more or less hairy. Paraphyses distinct. Spores with one, two, or four cells. We give this genus a wider scope than Winter, and include species with one, two, and four-celled spores of hyaline or light colour, and whose 196 ASCOMYCETES. other characters coincide ; this seems to be all the more justifiable since one finds on the same species asci with spores made up of one, two, or four cells. Trichosphaeria parasitica Hartig.^ (Britain and U.S. America.) Everywhere in young naturally regenerated woods of silver fir, especially in damp places or where the plants are crowded, one finds partially browned needles hanging loosely from the twigs, held only by a fine white mycelium (Fig. 87). In addition to this, one finds in spring young twigs completely enveloped in mycelium, with all their Fk;. ST. — Trichosphaeria parasitica on Silver Fir. The withered and dead needles hang loosely downwards, attached to the twig only by a white mycelium, (v. Tubeuf phot.) needles killed, so that the twig itself soon dies. The white mycelium grows especially on the under side of the shoot, and on the lower epidermis of the horizontal needles. A pseudoparenchyma, consisting of layers of mycelium, is there laid down, the lowest layer of hyphae sending short cone- shaped haustoria into the walls of the epidermal cells (Fig. 88). Inside the needles, occupying the intercellular spaces, there are numerous branches of septate hyphae, which kill the cells of the leaf. The perithecia occur here and there on the mycelial coating outside the leaf; they are spherical and blackish, with radiating hairs. They contain paraphyses and ^ R. Haitig, "Ein neuer Parasit d. Weisstanne. " Alhri. Fornt.-u. Jatjd- ZtitwKj, Jan., 1884. TRICHOSPHAERIA. 197 asci, the latter with eight four-celled light-grey spores, which germinate directly and distribute the fungus over new host- plants. I found this same fungus on Tsuga canadensis ^ at Baden- Baden, and on spruces in several parts of the Bavarian forests.- It, however, rarely attacks spruces, although they often occur in the same forest with firs. One of the cases of infection referred to above was caused by the diseased branch of a fir lying in contact with a twig of the spruce, so that the mycelium grew from the one to the other ; the spruce needles were killed, and woven on to the twig by hyphae. Fic. S8. — Trichospkaeria parasiliai. Mj-celial cushion on lower side of Fir needle, a, Fil.amentous mycelium, which, at d, send.s downwards numerous branches to produce a ciisliioi] (.f jiaiullel hyphae, c. Where the mycelium rests on the epidermis, rod-like hausturia arc sunk into the outer wall of the epidermal cells, e e; d shows the mycelial cushinn slightly detached from the epidermis, so that the haustoria have been withdniwn. .//, Epidermal cells filled with brown contents. !), a). 210 ASCOMYCETES. 3. Brown, multiseptate conidia : {a) In brown, very large, smooth-coated pycnidia (Fig. !)!), h). (b) In darker and smaller ]\vcnidia with pointed aperture. 4. Brown, l)ieellular conidia, in little dark pycnidia (Diphdia a/U'si). B. Perithecia. o. Brown, mnltiseptate ascosjjores, in perithecia generally of dark colonr, and with depressed pore (Fig. 100). Cucurbitaria sorbi K;ir.steii. This fungus appears to pro- duce disease in a manner similar to C. laburni. It was described by me in ISSG^ from specimens collected in the Bavarian forest-land from young Pynis Ancuparia. They were easily distinguished in August by their withered twigs, both l)ark and wood being killed in tracts by the mycelium. In another locality I found well-developed perithecia, also on P. Aimqmria. Cucurbitaria pityophila Fries, occurs on the living branches of vaiious conifers, cr/. Finns Cemhr/i. SPHAERELLOIDEAE. Stigmatea. The naked perithecia are superficially seated on the sub- stratum. The ascospores, eight in each ascus, are clear and two- celled. The species are parasites. Stigmatea robertiani Fr. (Britain and U.S. America). Occurs on living leaves of Gcniniam Rohertianum. St. ranunculi Fries. On living leaves of Piannacuhis rcpens (Britain and U.S. America). St. mespili Sor. (U.S. America). This species appears in spring as reddish-brown spots on the leaves of wild pear-trees. At these places the epidermis becomes ruptured, and cushions are formed from which brown conidia are given off from short conidiophores. This stage was formerly known as Morthicra mespili. The conidia are at first obovoid, but later seem to consist of four separate cells arranged in a cross, and each furnished with a transparent bristle. Each conidium produces a germ-tube which penetrates the epidermis, and in a month ^ 1 have since found from Saecardo that this fungus was described by Karsten {Mycol. Fenn. , ii. " ad rainos dejectos Sorbi anru[)nricui in Fennia merid. et media ") ; it was, however, unknown for (rermany to that author. (Auth.) STKJMATKA. , 211 new conidial cushions may appear. The mycelium itself is brown. From winter to spring-, brown perithecia containing,' eight-spored asci may be found on the same leaves formerly occupied by the conidia. The colourless spores consist of two unequal cells ; they germinate in May, before or after ejaculation from the asci, and bring about new infections. St. polygonorum Fr. occurs <>n leaves of Po(i/gon(im. (Britain and U.S. America). St. andromedae Rehm. On living leaves of Andromeda polifolia. St. alni Fuck. On living leaves of Alnus glutinosa. St. juniperi Desm. On living needles of Juniperus communis. Ascospora. The mycelium forms brown crusts under the host-epidermis, and there the perithecia develop. The asci are small and contain unicellular hyaline spores. The perithecia contain no paraphyses. Ascospora Beyerinckii A'uill.^ The conidial form of this fungus {Coryneum Beyerinckii) produces a form of the " gum- liu.x " of cherry trees. The mycelium lives in leaves of cherry, peach, plum, apricot, almond, which in consequence become spotted, and die oft' along with the young fruit. Mature perithecia may be found in spring. The fungus lives to a certain extent as a sapro|)hyte. Sphaerella. The delicate perithecia are embedded in the tissues of the host-plant ; they contain asci with two-celled colourless spores, but no paraphyses are present. Sphaerella laricina Hartig.- The needle-cast fungus of Larch. Tliis fungus is the cause of a dangerous larch-disease found everywhere, except in mountainous localities over 1200 metres. The symptoms of disease consist in the needles becoming brown-spotted and falling prematurely in summer. Cushions of conidia are formed in June on the brown spots ; these enlarge, and from their surfcice rod-shaped, ibur-celled conidia are * Vuillemin, Titrts ei travanx scientijiqm.i, 1890. - R. Hartig, Forstlich-natiirw{.s>s. Zeitxchrift, 1895, p. 445. Through the kindness of Prof. Hartig we have been enabled to add an account of this important new disease, with the accompanying figures. (Auth. and Edit.) 21; ASCOMYCETES. abjoiiited (Fig. 103); in the interior of the spots are produced tiny conidia {Lcptostroma laricinum), incapable of germination. Fig. 101.— Tuft of larch needles, the greater number of which are more or less attacked by Sphaerella laricina. (After R. Hartig.) The rod-shaped conidia infect particularly the lower needles of the crown, and three weeks thereafter new conidial cushions M^ T^ff^ Fifi. lO^i.— Sphaerella laricina. Section through a diseased spot on a larch needle. The interior of the leaf is permeated with the intercellular mycelitim. Two conidial cushions are shown ; from these numerous long rod-shaped conidia are given off externally (those of the upper cushion have nearly all been carried off by rain), while cavities inside the cushions are filled with micro-conidia. X if ii. (After R. Hartig.) appear. Their distribution and germination are facilitated by wet weather. The perithecia (Fig. 104) are matured towards SPHAERELLA. 213 spring ill the fallen needles, which lie on the ground over winter. The ascospores are mature and capable of infection at the beginning of June. In forests of pure larch, or in mixture with spruce, the ascospores are easily distributed by wind. In larch, underplanted with beech, the spores are kept down towards the ground by the canopy of beech foliage, so that, during the summer, they cannot be carried up to the larch crown. Hartig gives the following interesting fixcts on its distribution. ,, . , , 11,1 -^1 • 1 Fio. 103.— o, Rod-shaped As already remarked, the perithecia de- conidia before and after , . . ,ipn 11 11 detachment from the velop in spring on the lallen larch needles, basidia. 6, Micro-conidia 1 . , , . IT,' ,1 1 from the interior of the and in low-lying localities the spores reach cushions, x ^1". (After maturity at the beginning of June. New ^- ^^'^^'kO conidial cushions are not found on the larch in our neighbourhood before July. The parasite has thus four months at its disposal 's'j Fig. 104. —Spiiaerclia larktna. Section through a diseased larch needle in .June after it has lain on the ground from the previous j-ear. The mycelium is thick, thick-walled, and of a light-brown colour. The perithecia contain asci and asco- spores. To the extreme right is a pycnidium containing little oblong conidia, alongside a perithecium. x J-^". (After R. Hartig.) for distribution by means of conidia. As, however, we ascend into the mountains, the snow lies longer, so that the perithecia cannot begin to form so early, the ascospores are correspondingly late in reaching maturity, and the season during which the parasite may spread is still further shortened by tlie earlier commencement of winter. At an elevation of 1500 metre.s, 214 ASCOMYCETES. active vegetation begins about two and a half montlis later than in the plains, i.e. at the beginning of June. The season of mature spores of Sphaerdla is thus delayed till about the middle of August. On 26th September I found at this elevation only a few spots on the larch needles, and on these hardly any conidial cushions. By 28 th September this larch plantation was already under snow." " It will thus be seen, tliat while at a high elevation the larch can flourish with a vegetative period extending only to three and a quarter or four months, the Spliacrclla has not the time necessary for its develop- ment, so that the larch, though much handicapped, remains healthy. Similarly with the larch in Siberia, it grows there, as in the mountains, very slowly, yet this parasite can no longer reach it." Sphaerella fragariae Tul. Strawberry leaf - blight.^ In summer free conidia {Ramularia Tulasnci Sacc.) and pycnidia the iDcrithecia ripen in spring. [This destructive disease of the strawberry has been recorded from all parts of the United States. It first appears on the upper surface as small reddish spots, which rapidly enlarge, the centres withering and browning. The growth of the plants and the crop-yield is seriously impaired.] (Edit.) Sph. gossypina Atks.^ [Cotton leaf-blight is a disease on leaves of the cotton plant caused by the 6V'/TO.^w?Y^-stage of this fungus. Small reddish spots appear on the leaf, enlarge, and become dry whitish spots with a red margin. The conidia are elongated and produced in long chains. The asci contain eight elliptical spores, which are slightly constricted at the septum when mature, one cell being usually somewhat smaller than the other. This disease frequently accompanies that one known as "yellow leaf-blight," or mosaic disease.] (Edit.) Fici. 105.— Enlarged asci. a, Immature asci without paraphyses, as on April 30. b, Mature asci, from one of which the spores are escap- ing, as on June 1. x ^\'-^. (After R. Hartig.) are produced, whilt ^ Trelease, Wincoiisiii Exp(r. Station, ISSa. Scribner, F. L., Report U.S. Dtpt. of Aurindture, 1887. Plate. Other papers by Arthur, Dudley, and Garman. 2 Atkin.«on, IhdUtin Torrey Botan. Club, Vol. xviii., 1891. SPHAERELLA 215 Sph. mori Fuck, causes a similar disease on leaves of nuilherrv (U.S. America). Sph. taxi Cke. On the yew." Sph. longissima Fuck. On living leaves of Bromus asper. Sph. depazeaeformis (Auersw). On living leaves of Oralis acetosella and Ox. corniculata. Sph. brassicicola (l)ub\.). On withering leaves of Bmssicae. (Britain and U.8. America. Sph. laureolae (Desm.). On living leaves of Daphne hmreola. -Sfihaeretla fragariae on leaf of Strawberry. The .section tlirough a spot shows formation of conidia. (v. Tiibeuf del.) Sph. hedericola (Desm.). On living leaves of ivy. (Britain). Alleseher- describes other fungi on ivy. Sph. Gibelliana (Pass.). On living leaves of Citrus limonum and C. medic". Sph. polypodii (Raljh.). On living fronds of Poft/podiitm vulgare, Aspidium Fili.r-raiis, Asplenium Tn'chomanes, Pteris aquilina. Sph. vitis Fuck. On withering vine-leaves. 1 Worth. G. Smith, Gardener'^ Chronicle, xxi., 18S4. 2 Alleseher," Blattfleckenkrankheitd. Ephues,"Z'iV>'//. ;". /^//. -/•/>(»//,. //.*/. Is!)."). 216 ASCOMYCETES. Sph. sentina (Fr.) (U.S. America). In spring of 1891 this caused at (leisenheini ' a severe spot-disease on the leaves of certain varieties of pear. Other related species occur on pear. There are numerous other species of Sphacrella, Saccardo gives i79 species, many of which are probably more or less prejudicial to ])lauts in orchard or garden. None, however, are recorded as very injurious. Laestadia.- This genus is similar to Sphaarlla, but lias one-celled conidia ; it is distinguished from FJu/salosjwra by the absence of paraphyses. L. maculiformis (I>on.) on living leaves uf various trees. L. (Physalospora) Bidwellii (Ellis)^ (Britain and U.S. America). The Black-rot of the A^ine. This parasite attacks all young organs and shoots of the vine. On the leaves the symptoms are spots with dark sharply-defined margins, on which the pycnidia appear later as minute Ijlack pustules. The leaves die, but do not fall off, as with Sjjhaccloma ampclinvrii. The berries show disease when only the size of peas, and finally fall off singly or in clusters. The grapes are not dusty with a mealy powder, nor do they burst as in attacks of Oidivm Tuckeri. Two kinds of pycnidia occur: one sometimes described as spermogonia, has very small rod-like conidia, borne on thread- like conidiophores ; these conidia have not as yet been seen to germinate. The other pycnidial form (FJioma uvicola of Berk, and Curt.) contains forked filamentous conidiophores, from which one-celled ovoid conidia (stylospores) are produced and soon germinate by emission of a septate hypha. The latter form of conidia is produced after the spermogonia, and may be ' Geisenheim Jahrhuch, 1892. '^According to the laws of priority this genus must, as shown by Magnus {Oesterreich. hotan. Zeit., 1894, p. 201), be called Carlia. Bon. •'Bibliography: Cavara, Intorno al dissecamento dei yrappoli della rite, 1888. Thiimeu, " Die Black-rot Krankheit d. Weintraiiben." Alleg. Weinzeitum/, Vienna, 1891. Galloway and Scribner, Reports for 1888-89, U.S. Dept. of Agriculture. Viala and Ravaz, Les Pror/res aqric. et vificole. Montpelier, 1888-89. Rathay (1), Ihr ninrl-.rol, 1891. With 19 figures (2). Berirht iih. eine narh Frankreich z. En'or^rlinini d. Black-rot Krankheit Beise, 1891. With 7 figures (3). Der White-rot h, ,li, \V,n,/anhe, 1892. Viala. Dii' Krankhiiloi d. Wrinstockex. Linhart u. Mezey, /)!>- Krnukhdten d. Weinntockes, 1895 (Hungarian). U.S. Dept. of Agriculture. Numerous references in reports and bulletins, where details of treatment experiments will be found. LAESTADIA. 217 found light on into autumn, even throughout the winter. Hibernating sclerotia are also produced, the cells of which grow out directly into septate conidiophores with oval conidia. Perithecia, externally resem1)ling pycnidia, are formed in May and June on the fallen berries of the preceding year. The asci have gelatinous walls, which swell and burst so as to ejaculate their spores. Viala and Eavaz successfully infected living grapes by means of the larger conidia, and also by the germinating ascospores. The disease is one of the most dreaded in America. It has been found also in Europe, having been observed in France since 1885, though not as yet in Germany, Switzerland, Italy, or Spain. Moist situations are favourable to it. As with other diseases of the vine, the various varieties liave ditl'erent powers of resistance, and a judicious selection of varieties may prove a good preventive measure. According to Yiala, the blaek-rot is founil in the United States on both wild and cultivated vines, but never on the fruit of Vitis rujjcsfri.s, V. Bci'lancici'i, V. cincrca, V. Lii/seroinii, V. Monticola, and V. candicans, and very rarely on their leaves. Tlie "vine-stocks" themselves suffer little or nothing from the disease. IJathay says that Vitis riparia, V. rupestris, and V. Solonis, so im- portant as grafting-stocks, are seldom affected ; the green shoots, of other species, however, may be attacked and the disease be transmitted through the graft-slip. For combating the disease, Galloway, Prillieux, and FEcluse recommend Bordeaux mixture.^ Laestadia buxi (Uesm.). The perithecia of this species are found as tiny points on yellow spots on tlie lower surface of green leaves of box. This fungus, regarded by Desmazieres as saprophytic, is said by Briosi and Cavara to be parasitic. PLEOSPOREAE. Physalospora. The perithecia are formed under the epidermis, but are otherwise devoid of covering ; they contain asci and paraphyses ; the spores are one-celled, and ovoid or elliptical. ^For details see Rathay (he. cit.), the American bulletins, etc. 218 ASCOMYCETES. Physalospora laburni (Bouord.) occurs on living twigs of Ci/tisus LahurHum. Ph. fallaciosa Sacc. On withering leaves of Aletris and Musa in Berlin Botanic Garden. Didymosphaeria. Peritlieeia similar to Fht/si/hispn/yi, Init with two-celled spores. Didymosphaeria genistae Fuek. occurs on (Jenista pilosa. D. epidermidis (Fries). On living branches of Berbens, Sambucus, Salu\ and Eiicidjiptns. (Britain and U.S. America). D. albescens Niessl. On living branches of Lonicera Xylosteum and Myricaria germanica. D. dryadis (Spegazz.). On living leaves of Dryas octopetala. (U.S. America). D. populina Vuill. Prillieux and Vuilleniin ^ regai-ii this as a parasite, and the cause of a peculiar dying-olF of Popuhis pyramidalis throughout Germany ; Rostrup, on the other hand, ascribes this to Dothiora sphacriodes Fr. Prillieux regards Napidadium trenndae as a conidial form of Didymo- sphaeria ; Yuillemin, however, believes it to be saproijhytic. Venturia. The perithecia are embedded in the stroma, and have stiff" bristles round the pore ; they contain both paraphyses and eight-spored asci. The spores are two-celled, with or without colour. Venturia geranii Fr. occurs on the living leaves of Geranium pusilh'.m, G. .nolle, etc. V. rumicis (Desm.). On withering leaves of Itvme.r. (Britain). V. maculaeformis (Desm.). On living leaves of Epilobinni. V. vermiculariaeformis Fuck. On withered leaves of Euonymus europaeus anil Lonici:ra Xylusteum. V. Straussii Sacc. et Roum. This I havi- fdund as a parasite on Erica carnea in Tyrol. It is also said to cause a disease on Ericaceae in France. The various conidial I'oniis at present placed amongst the "Fungi imperfecti " as Fi'HicIdjIiiiui are proljaldy related to Venfvrii'. Fusicladium dendriticum AVallr. on apple, and F. pirinum Lil). on pear, are at present the sul)ject of an in\-estigation at tlie hands of Aderhold,- who has, on account of their perithecia, ^Bidlef. de la sor. myrol. d,: France, 1S92; Conipf. rem/., 1SS9 ; Rcrw mijrol., 1892. -Aderhold, "Die Perithecienforni v. Fns. deudriticiim '' yorliiwtig Mittlieiluiig> Ber. d. dcidsch. hotan. Ges., 1894, p. 338. VENTUKIA. 219 })lacecl them in the genus Ventirrio. His investigations are, however, not (juite complete. The scab or black spot of apple and pear is a very familiar disease in America and elsewhere. It attacks leaves, young shoots, and fruits. Dirty greenish spots appear first, then enlarg- ing, they run together, and darken in colour till almost black. If the attack occur on young foliage, it may be dwarfed and killed ; the newly-formed fruit will in such cases be attacked, shrivel up, and fall. If the attack be deferred till the foliage and fruit are well advanced, theii .spotting results and the fruit remains hard, perhaps cracks. The conidia are oval, unicellular, and yellowish-brown ; they are produced from short conidiophores Fig. 10'. — Venturio. {Fti.dclodiv.m) dendritici-m forming br•- ---?SS'?5*_ FiG. W9.— Valsa o.ri/stoma on Alnus viridi*. A, Portion of branch with stroma of Valsa breaking through the periderm at four places. B, EnLirged section through a stroma from A. C, Asei and ascospores, isoLited from a porithecium. Z), Portion of younger branch with periderm ruptured by .stromata, in which, however, the perithecia are not yet developed. E, Enlarged section tlirou>.'h :i stroma of D. (After v. Tubeuf.) with the exterior by means of long projecting necks. llie asci contain eight unicellular spores of a slightly bent, rod- like shape. Maturity is reached on the dry dead twigs. Externally this disease is identical in appearance with one I ascertained to be due to a beetle {Cryiitorhynchm lapathi), p 226 ASCOMYCETES. the larva of which bores canals in the wood of aklers, birches, and willows, causing them to die. ]\Iost of the other species of Valsa cause only leaf-spot, or occur on dead leaves. Anthostoma. The perithecia are embedded in the substratum or stroma, and have generally long necks. The asci contain eight brown or black, oval, unicellular spores. Paraphyses are always absent. Anthostoma xylostei (Pevs.) occurs on living and dead branches of Loniccra Xylosteuvi. (Britain). Anthostomella pisana Pass, lives on leaves of Chamerops /mmilis and kills them. DIATRYPEAE. Calosphaeria. No stroma is formed, the perithecia arising singly or in groups in the bark under the periderm; they have often long beaks. The asci are club-shaped, and frequently long-stalked : they contain eight or more spores, which are little, unicellular, and somewhat curved. Calosphaeria princeps Tul. occurs on living branches of cherry and plum. (Britain and U.S. America). Quaternaria Personii Tul. has black perithecia and, according to Will- komm, causes death of twigs of beech. (Britain and America). MELANCONIDEAE. Aglaospora. The perithecia are beaked and embedded in the stroma. Tlie spores are furnished with appendages. Aglaospora taleola Tul.^ {Diaporthe talcola Fries, and pro- bably nearly related to those Melanconi with appendages on their spores, e.g. Mel. thelehola, previously known as Aglaospora thel. Tul.). (Britain and U.S. America). This fungus causes a disease of twigs and young stems of oak which have not iR. Hartig, " Kine krebsartige Riiulenkranklieit d. Eiche," Forsliich-nalvriviss Ztitschrift, 1893. AGLAOSPORA. 227 Fio. 110.— Examples of Oak -stem atticked by Aylaotpora taleola.. 1, Portion ■diseased for two years ; a, the portion still healthy ( x |). 2, Portion diseased for four years ( x i). 3, Section with spots diseased for four, seven, and ten ^'ears respectively ( X \). (After R. Hartig.) 228 ASCOMYGETES. as yet formed a bark. Portions of the rind become brown, dry lip, and peel off"; this on stronger twigs may be followed by a more or less complete occlusion of the wounded part. The browning also extends into the underlying wood. The mycelium is found both in rind and wood, where it probably obtains entrance through small wounds in the bark. In the second year after infection, a circular stroma is formed in the 1)ark under the periderm. Sickle-shaped conidia are Fio. 111. — Aglaospora taleola. Portion of cortex with embedded stromata. (!, Corky layer ; 6, after removal of corky laver ; c, section of stroma. ( x ^. ) (After Hartig.) ■j^^^^^^ Fio. 112.— Section of stroma of Aglaospora. a, Boundary of stroma formed of dark brown fungus - mycelium ; 0, scleronchyma-strand of the cortex ; c, conidial cusljion ; d, union of necks of two perithecia. (After Hartig.) Fig. 113.— a, Conidia ; b, asco- spore of Aglaosjwra taleola ( X if^). (After Hartig.) superficially abjointed from the stromata ; while embedded in it are groups of perithecia with necks which join together into one or a few common channels opening externally. The asci contain eight spores, which are two-celled and bear five thread-like appendages, one on each end, and three round the median septum (Fig. 113). AGLAOSPORA. 229 Ag. profusa Fr. (Britain and U.S. Anieiica). This occurs along with, and probably is some form of Dothiordla roJnniae. Prillieux and Delacroix ^ blame it for killing young twigs of Rohinia pseudacacia in France. Fenestella. The stroma is similar to Eit- Valsa, and contains several long-necked perithecia. The spores, eight in each ascus, are coloured and multiseptate, as in Cucurbitaria. Fenestella platani Tav., to this is probably related Gloeo- sporium nerviscquium (Fuck.), the cause of a disease on the leaves of Platanus, and described under Glocosporium. (3) DOTHIDEACEAE. Phyllachora. The perithecia are small and produced in a black stroma buried in the tissue. The asci contain eight hyaline, oval, and unicellular spores. Phyllachora graminis (Pers.). (U.S. America). Tliis species causes elongated black swellings on grasses and sedges (Luzulu and Carcx). The black perithecia occur massed together, and embedded in the leaves. The asci contain eight hyaline uni- cellular spores. Ph. trifolii (Pers.), with conidial form known as Polythrinciinn trifolii Kunz. (Britain and U.S. America). The mycelium causes the formation of roundish dark spots on the green leaves of clover frequented by it, and death ultimately follows. On the spots, especially those on the lower epidermis of the leaf, the conidiophores make their appearance as brown septate structures, constricted at intervals so as to become rosary-like : they bear terminal, brown, two-celled conidia, the upper cell of which is somewhat spherical, and larger than the lower. Ph. cynodontis (Sacc). On living leaves of Cynodon Dartylon. Ph. podagrariae (Roth.). On living leaves of AegopofUnm Poihniraria (Britain). Some other species are found on withering leaves. ^Bulletin ■•ioc. mycol. de Franre, 1890. 230 ASCOMYCETES. Diachora onobrychidis {D. C.)} This fungus is common on sainfoin (Onohrr/chis sativa) and Lathyrus tuhcrosus, causing black spots on both surfaces of the leaf. During summer pycnidia arise on the spots, and from them are produced spindle- shaped conidia (spermatia) with tail-like appendages. Later there arise spherical perithecia containing asci arranged in tufts on the walls. The asci contain eight oval, hyaline, unicellular spores. Dothidella. The perithecia are black and embedded in the stroma, similarly to Pliyllacliora . The pale-coloured spores are, how- ever, two-celled. Dothidella betulina (Fries.). (Britain and U.S. America.) The black stromata form spots on the upper surface of birch leaves. In these the perithecia arise, and reach maturity in spring. The asci contain eight elliptical greenish spores, consisting of two unequal cells with rounded-off ends. D. ulmi (Duv.). (Britain and U.S. America.) A species similar to the preceding, and causing round blistered spots of a grey colour on the upper surface of elm leaves. Pycnidia {Piggotia asfroidea) are formed in summer, perithecia in the following spring. Dothidea. The stromata have the form of black projecting cushions, in which numerous perithecia are embedded. The asci contain eight greyish or brown spores, consisting of two cells with a constriction between tliem. Dothidea virgultorum (Fries.) attacks livijig branches and stems of l)irch, and develops further on the dead parts. The stromata originate in the wood, then breaking through the bark, make their appearance externally as large black cushions. Whole stems may be covered by these cushions. D. sphaeroidea (C'ke.) occurs on living needles of juniper. Plowrightia. The stromata are black, and run together in masses. The asci are eight-spored : the ascospores ovoid or oblong, hyaline or light yellow, and two-celled. 'J. MuUer, Prhnj.sheim's Jahrbuvh, 1S9.3. PLOWKIGHTIA. 231 Plowrightia morbosa (Sch.) (Britain and U.S. America). Black-knot of the plum tree.^ In America thi.s is a very Fio. 115. — Ploirriiihtia mor- hosa. Ascus, with eight spores. Spores in germinn- tion. Filuinentou.s jwira- physes. (Cop. fnmi F!\rlo\v.) Fig. 114. — Plowrightia morbosa. (v. Tubeuf phot.) injurious and widely distributed disease of various species of Prunas, especially plum and cherry. The living branches and twigs become coated with a crust of warty excrescences, and at the same time are more or less thickened and deformed. A mycelium permeates the tissues of those swollen twigs, and forms black crusty stromata in which the perithecia are embedded. The perithecia contain simple paraphyses and eight- spored asci. The spores consist of a larger and a mucli smalk-r cell. (Pycno-conidia arc produced frequently in artificial culture, 1 Fallow, Bulletin Bussey Institution, Part v., 1876. Humphrey, Animal Report of Mans. Exper. Station, ISOO. Lodeman (Cornell Uvii: Exper. Station. Bulletin No. 81, 1894) giv.-s general account of Black-knot and a Bibliography. 232 ASCOMYCETES, but are rarely found in natural conditions ; as yet infection with these has had no result.) [Remedial treatment must be promptly applied. Trees liable to attack should be frequently examined, so that any young knots may be early removed. If the disease is of long standing, the only remedy left is to remove all knotted branches and burn them immediately.] (Edit.) HYSTERIACEAE. The ascocarps of the Hysteriaceae, like those of the Discomy- cetes, are known as apothecia. They are distinguished from those of the Pyrenomycetes and Perisporiaceae in that the ascocarp, although formed in or under the epidermis of attacked plant-organs, is not a closed structure or flask opening by a pore only ; it is, indeed, at first completely closed, but later it, as well as the epidermis covering it, splits open and freely exposes the whole hymenium. So long as the apothecium is closed, it is filled with paraphyses, between which the developing asci gradually wedge themselves. The spores are generally thread-like, with a gelatinous membrane. The mycelium lives intercellular, and is often parasitic in living plants. The apothecia, however, only reach maturity on parts which have been killed. In addition to apothecia, little pycnidia (spermogonia) are formed, containing small unicellular conidia. The Hysteriaceae include the HysUrincac, Hypodermuac, Dichac- naceae, and Acros2}e7'maceae. HYSTERINEAE. Hy sterographium . Apothecia black, highly vaulted, and dehiscing by a linear fissure. The asci are club-shaped and thick-walled ; they con- tain eight multicellular spores, which are at first transparent, but later dark-coloured. The branched paraphyses of the U]i]>er part form a coloured epithecium.^ Hysterographium fraxini (Pers.) (Britain). This occurs on various Oleaceae and some other species of woody plants. ^The excipulum of De Bary. HYSTEROGRAPHIUM. 233 Eostrup^ regards it as a parasite on Fraxinus. Twigs of the ash attacked show flat collapsed plates of bark, ou which are developed pycnidia containing one-celled conidia, and, later, the apothecia. On young twigs the diseased, part often extends round the whole circumference, and causes the death of tlie upper living part. As yet I have only found tliis fungus as a saprophyte, HYPODERMIEAE. Hypoderma. The apothecia are oblong, and at tirst closed by a thin black cover, which opens by a long fissure. The asci are sessile in Fig. lit". — Hijpoderma strobicota on Pinvs Strobus. Ascus containing eight ascospores with gelatinous coats ; paraphyses with clavate ends. (After v. Tubeuf.) Fig. 117. — Hirtxxitrnia Dlrobicolo. Isolated ascospores : with and without a gelatinous coat, and one- or two-celled, (.\fter v. Tubeuf.) some species, but have a delicate stalk in others. The spore.s, eight in each ascus, are never long and thread-like, but always much shorter than the asci, and two-celled when mature. The paraphyses have button-shaped or hooked ends. Hypoderma strobicola- (Rostr.). Needle-blight of the Wey- ' Rostiup, Forf.iatte l7nder.^oe(jelser ov. SnyUesvampeH Angreb pan Skor- traeerne, 1883. -Rostrup, Forfmfte Under soegelser, 1883. V. Tubeuf, Bait. -;. Kenutniss d. Baumtrankheifeu, 1888 ; also Bolaii. Centralhlatt, XLi,, 1890. Note : When I decided to place Lophoderminm hrachy>iporum under the genus Hypoderma, there already existed a Hypoderma hrachysporam Speg. (1887). For the future I shall therefore call Loph. hrarhyxponim Rostr. a.s Hypoderma strobicola. 234 ASCOMYCETKS. mouth pine. According to the observations of liostrup in Denmark, and myself in various localities of Germany, this is a dangerous parasite on Pinus Strohus. It kills the needles and young shoots, and may devastate whole tracts of forest. The diseased needles become brown in summer, and fall off during next winter. On them are produced apothecia containing club-shaped asci and paraphyses with button- shaped ends. The eight spores of each ascus are at first unicellular, later apparently bi- cellular, and enclosed in a very mucilaginous Fig. 118. -Leaf of ^Hca coat. The ascl havc an average length of 'Co".™i!\X?ofth1 120/x, the spores 20m, and when swollen lower surface. 1, An .^ q f ^ o n entire and a dehiscing -^^ ^' 'J "A'- spore.= '( t^Tuw deT)" H. piiiicola Bruuch.^ forms linear apothecia on needles of Fimis sylvestris. H. ericae Tubeuf.- In Tyrol and Northern Italy, this fungus causes a disease on Erica carnca. It is common and epidemic, causing death of the leaves. Hypodermella. Similar to Hyidodcrma, except that the spores are pear-shaped and unicellular ; they occur four in each ascus, and are shorter than it. Hypodermella sulcigena (Link)'' has four long, club-sha]->ed, unicellular spores. Eostrup regards it as parasitic on Pinus montana and P. si/lrcstris, its mycelium being found in living green needles, and causing their death. Hyp. laricis Tubeuf.- This is a new fungus of the larch- needle found by Tubeuf on the 8onnenwendstein (Bavaria) in September, 1894, It was present in large quantity on larches on the upper part of the mountain, and was in every way so decidedly parasitic in character, that there is little doubt as to its being an epidemic disease. The full-grown needles on many of the foliar spurs had died oft' and turned lu'own. The ' Brunchorst, Xoh(nlermium ahi- ctis on Spruce. (After Ro.strup.) Fio. 122.— Loiyhodenniv.m maa-osporum. Section tliruugh a mature dehiscing apothecium. (After R. Hartig.) summer, reaching maturity on two-year-old needles. Again, the needles of the two-year-old shoots become brown in autumn, and perithecia appear on them in the following summer, ■ Preventive measures are discussed in greater detail in Prof. Somerville's translation of Hartig's Diseases of Trees, p. 115. -R. Hartif', Wichdqe Krankheilen d. Wahlhaume, 1874. 238 ASCOMYCETES. ripening in the spring of the fourth year. Or, again, a *' casting " of brown one-year-old needles may take place in autumn. The disease is found everywhere, but in some parts {e.g. in the forests of Saxony ^), it is exceedingly common and very dangerous. The apothecia are developed as long, shining, black swellings on the two under surfaces of the quadrangular needles (Fig. 121). The club-shaped asci emit thread-like spores with gelatinous coats. The ascospores produce a strong germ-tube, which grows inside the needles to an intercellular mycelium without haustoria. Browning and shrinkage of the cells of attacked needles soon follow. The myce- lium also penetrates into the cells of the epidermis, and develops there a coil of hyphae, which, under a black membranous cover, forms an apothecium containing paraphyses and club-shaped asci (Fig. 122). When ripe, the apothecia rupture the overlying epidermis. Little black pycnidia (spermogonia) may also occur on diseased needles.^ On needles which have been prematurely cast, only little spherical apothecial knobs will be found. According to Hartig, the effects of this fungus on the cells of attacked needles is very interesting. If the disease of the needles appears in autumn, the cells, which at this time are void of starch, become brown and die. If the disease attacks in May, when the needles are rich in starch, their death ensues soon, but the starch only disappears gradually from October onwards, as it is used up by the fungus-hyphae. If the disease appears in •spring, when starch-storage is just beginning, the cells already attacked become quite full of starch, whereas the other cells of the same needle remain empty. ■ ^ Nobbe, Ber. d. sdchsisclies Forstvertinn Versammlung zu Schandan, 1891. - Another ascomycetous fungus — Naevia piniperda Rehm — occurs alone or together Nvith this species ; Rehm regards it as parasitic {Hedwigia, 1892, p. 302). Fig. 123. — Lophodermiiim maerosporum on Spruce. Oerminated ascospores ; ■some have germinated inside the ascus. (After R. Hartig.) LOPHODERMIUM. 239 Lophodermium nervisequium (D. C.)^ (U.S. America). This very common fungus attacks both old and young silver firs. The needles die after becoming brown, and remain for a long Fig. 124. — Lopliodevmium nervisequiu-m on Abies pectinata (Silver Fir). 1, Under surface of needle with apothecia. 2, Upper surface with pycnidia. Fig. 125. — Lophoderniimn nervisequium. Section of a needle of Silver Fir. 6, Pyonidium on upper surface shedding conidia. a, Apothc- cium on the lower surface. (After R. Hartig.) Fig. i26.— Lophodermium nervisequium on Silver Fir. Portion of a ripe apothe- ciuin. a a, Filamentous paraphyses ; rod-like cells (conidia?), k, abjointed from the apex of the paraphyses ; the asci contain eight spores about half as long as the ascus itself, four occupying the upper half, four the lower ; c, a rudimentary ascus ; some mature spores possess a gelatinous coat, others do not ; spores escape by an apical opening, c, or by rupture of the ascus,/; two germinating spores are also shown, one with a gelatinous coat, the other without. (After R. Hartig.) time hanging on the twigs. The disease varies in its develop- ment on the mountains and lowlands, according to climatic conditions. ^R. Hartig, Wichtige Krankheiten, 1874. 240 ASCOMYCETES. The mycelium lives intercellular, and produces the same effects on the cells of the fir-needles as those of Loph. macro- sporum on the spruce. The mycelial hyphae penetrate into the epidermal cells and form a cushion, which bursts the epidermis and gives rise to numerous straight conidiophores, with very small, oval, unicellular conidia. The apothecia are developed while the needles are on the tree or after they have fallen ; they form shining black stripes on the middle nerve of the lower surface of the needle (Fig. 124). The thread-like spores have a mucilaginous coat, and are ejaculated from club-shaped asci (Fig. 126). Pycnidia (spermogonia) are often produced before the apothecia as long wavy bands on the middle nerve of the upper surface of the needle (Fig. 125). L. juniperinum (Fries.) (Britain and U.S. America). A common species on dead needles of Juniper commvnis, also on needles on the branch : I have, however, never seen it in such mass as to believe it to be a dangerous parasite. L. gilvum liostrup ^ attacks and kills living needles of the Austrian Ijlack pine. L. laricinum Duby. The pycnidia and apothecia of this fungus are common on dead needles of larch, but parasitism has not been proved. L. abietis Ilostr. A species found by Eostrup on needles of spruce, causing yellow spots and then large black points (Fig. 121,2). DISCOMYCETES. The Discomycetes have an apothecium of varying shape, but always more saucer-like than spherical. The ascocarp, at first a closed structure, opens sooner or later and exposes the hymenium. The apothecium is composed of two distinct portions of mycelium. The essential part, often called the hymenial layer, consists of hyphae which give rise to the asci. The remaining portion of the ascocarp forms a support or envelope for the hymenium; it consists of a pseudoparenchyma, and may be differentiated into a sub-hymenial layer or hypothecium with its hyphae interwoven with those of the hymenium, and a lateral portion or excipulum usually more or less cup-shaped. ^ Rostrup, Fort sat te Undersoerjelser, 1883. DISCOMYCETES. 241 The paraphyses are developed from the inyceliuin of the envelope and occupy the interior of the ascocarp, while the asci arise later from the ascogenous hyphae and force their way in. The formation of asci and paraphyses may go on for a long time. Periphyses are not produced. The Discomycetes include five divisions, the Phacidiaccac, Stictidrae, Tryhlidieac, Dcrmateaccac, and Pezizeae. Many of the species included in these are parasitic on cryptogamic plants to form lichens, the majority are saprophytes, and only a few isolated groups are true parasites on higher plants. The latter belonj^ to the Phacidiaccae, Dermateaccae, and Pezizeae. (1) PHACIDIACEAE The apothecia are black and thick-walled, at first embedded in their substratum, but later breaking through it. The asco- genous layer is spread out on a delicate flat hypothecium. The black apothecia of the species of Phacidium are frequent on leaves and needles. Eehm divides the group into two families : the EuplLacidieac and the Pseudophacidieac. EUPHACIDIEAE. The apothecia are embedded in the tissues of the host ; the superincumbent layers of the substratum forming over them a blackish membranous plate, which is ruptured into lobes and exposes the black apothecial disc. Phacidium. The apothecia are fused with the superincumbent layers of the host-plant, and the black cover so formed is split into several lobes. The club-shaped asci contain eight colourless, unicellular, ovoid or spindle-shaped spores. The paraphyses are filamentous. The pore of the ascus is coloured blue by iodine. Phacidium repandum Fr. (Britain). Occurs on living leaves and stems of Asperida odorata, Galium mollugo, and other Eubiaceae. The pycnidial form is probably Phyllachora punctiformis Fr. Q 242 ASCOMYCETES. Schizothyrium. The roundish or oblong apothecia dehisce by lobes. The clul)- sliai)ed asci contain oblong, hyaline, two-celled spores. Sch. ptarmicae Desm. (Britain). This occurs as a parasite on living green leaves and stems of Achillea Ptarmica. The apothecia form little black points, which on rupturing break -SchirMhy, V. Tubeuf del.) up the epidermis into lobes. The thick asci contain two to four large two-celled spores. Paraphyses are present. A pycnidial form is known as Lcptothyrium 2:)tarmicae (Sacc). Rhytisma. The fungi of this genus live in the tissues of living plants and form sclerotial cushions as isolated black spots. In these places the pycnidia are developed, and are followed by apothecia after the death of the leaves. The apothecia open by a fissure, and contain thread-like paraphyses and club-shaped asci with eight needle-shaped spores, which are septate when mature. Rhytisma acerinum (Pers.) (Britain and U.S. America). Tt)\var(l.s the close of summer, the large black spots caused by this fungus on leaves of various species of Acer (sycamore and maple) are by no means uncommon. Pycnidia {Melasmia acerinum Lev.), containing little unicellular conidia, are first produced under the cuticle, while the epidermis and under- Iving cells become filled with mvcelium till a black sclerotium RHYTISMA. 243 is completed. In the following spring, the sclerotiuni-spots on the fallen leaves have become thicker and superficially wrinkled. At this stage the apothecia are produced, and dehisce by fine elongated fissures ; they contain club-shaped asci and thread-like paraphyses with hooked ends. The thread- like ascospores are ejaculated with considerable force, and reach Fig. 128.— JihT/tisma acei-imou. Two apothecial cushions on leaf of Acer campestre in first summer. A, Leaf-apex of Acer platanoiJe» with the mature apothecial cushions as seen in the second summer, with their chai-acteristic wavy marking, (v. Tubeuf del.) maturity in :May or June. According to Klebahn,^ the spores have a mucilaginous membrane, but this does not throw much light on the problem of how they reach the leaves of trees; wind, however, would seem to be the agent for distribution. In three weeks after infection, leaves show yellow spots; in eight weeks the pycnidia appear. ^Botan. CentrcUhlatt , lviii., 1894, p. 321. 244 ASCOMYCETES. The disease is best combated by prompt removal of fallen leaves in autumn; where this rule is followed Rlujtisma is seldom found (see p. 71). Rhytisma punctatum (Pers.) (Britain and U.S. America). Whereas the spots of the Rhytisma just considered are large, those of this species seldom exceed a few millimetres. They are Fig. 129 — Rhytisma punctatum. Leaf of Acer Pseudoplatanus with apothecia ; the loaf is yellow, but the spots enclosing the apotheci.a are still green. (V. Tubcuf del.) black in colour, angular, and scattered over the whole leaf- surface. After the leaf has turned yellow, portions of it sur- rounding spots of this Bhytisma retain their green colour, so that we have black spots on green islands in the yellow leaf. The sclerotia dehisce by valves. The apothecia contain thread- like paraphyses and asci. The asci are club-shaped and contain RHYTISMA. 245 eight needle-shaped uniceUular spores ; pycnidia (spermogonia) with little unicellular conidia are also formed. The fungus attacks leaves of sycamore (Acer Pseudoplatanus), the black spots making their appearance in September. The apothecia ripen on the ground during the following summer.^ Fio. 130. — Sections of Maj^le leaves showing the upper epidermis ruistured by 1, Rhytisma acerinv.m ; 2, RhytUma punctatum. Fig. 131. — Rhytisma symmetricum Milll. Two leaves of Salix purpurea with stromata. A, The upper side. B, The lower side. C, Longitudinal section through the same leaf, showing numerous apothecia on the upper side, fewer on the lower ; the shaded middle part represents leaf-tissue, the remainder is the light fungal stroma in which the darker apothecia are embedded, (v. Tubeuf del.) Rh. salicinum Pers. (Britain and U.S. America). Thickened black wrinkled spots appear frequently on living leaves of various species of willow, c.f/. Salix Caprea, S. cinerca, etc., also on some alpine willows, e.g. S. reticulata. These contain apothecia of this fungus, which reach their full maturity during the second summer. ' Dyscomycopsis rhyttsmoides Ablill. Black spots similar to those of Rhytiama appear on the leaves of sj-camore. The black crusts are here only subcuticular and enclose a transparent tissue from which large spherical spores are produced. The systematic position of this fungus is unknown. 246 ASCOMYCETES. Rh. symmetricum -I. Miiller {Eh. autumnale Schroeter)^ is a form occurring on Salic purpurea and recently separated as a distinct species. This willow, one of the best for cultivation, may often be seen with its leaves covered with black spots, and the disease may spread over every tree in a nursery. The apothecia are found on the upper surface of the leaf, on black, shining, and much wrinkled cushions. In addition, black apothecial cushions are developed on the under surface of the leaf, which is not the case with any other species of Rhytisma. According to Schroeter, the spores ripen in autumn on still living leaves. (This species may be synonymous with Rh. australe Dur. et Mont, on Salix piirpurea in Algeria.) A species which causes little thick cushions on Salix Caprea has been called lihi/tisma umbonatum Hoppe. Rh. andromedae Pers. occurs on leaves of Andromeda polifolia. (Britain and U.S. America). Rh. empetri Fries, on leaves of Empetrum nigrum. (Britain). Rh, juncicolum Rehm on Juncxis Hostii. Rh. urticae Fr. on stems of Urtica dioica. (Britain and U.S. America). Rh. bistortae D. C. on Polygonum viviparum in France, Greenland, and America. PSEUDOPHACIDIEAE. The apothecia are at first embedded in their substratum, under the superincumbent layers of the host-tissue, and form blistered patches ; on rupture, this cover forms a rim round the apothecial cushion; the excipula of the apothecia themselves are memljranous, generally Ijlack, and dehisce by lobes or fissures on the apex. Cryptomyces. The apothecia break out from the substratum as black crusts. The asci contain eight oval, unicellular, colourless spores. The paraphyses are thread-like and septate. Cryptomyces maximus Fries.^ (Britain and United States). This fungus lives parasitic on twigs of various species of willow. 'J. Miiller, "Zur Kenntniss d. Runzelschorfs," Pringsheim's Jahrbnch, 1893. Schroeter, Flora v. Schkden, 1894. Both appear to be identical with Rh. amphigenum Wallr. {Flor. Cri/pt. ii. 412). - Tulasne, Select, fumjorum Carpologia, iii. CRYPTOMYCES. 247 especially Salve mcana, but also on S. 2^urpurca. When the black apothecial cushions break out through the bark, the twigs of the host-plant are frequently still green and leaf-clad. The apothecia originate in the lower bark and so loosen the epidermal layers as to cause the appearance of yellow spots. Black centres appear in the spots, due to the formation of a Fig. 132. — Cryptomyccs maximus. 1, Cross-section of a twig of SalLr incano, with stroma a b ; the mycelium occupies the rind and bast into the cambium, so that a wood-ring for the current year has been only partially developed ; the shaded part between a and h is an aerating tissue, formed of loose hyphae, which, with a, forms the stroma proper ; h, the ascogenous layer. (Lens-magnification.) 2, Asci, showing a dry ascus ; one to which water has been added, so that it is elongating ; one ruptured and ejaculating spores. 3, Young stromata in spring, still covered by the epidermis of the Salix. 4, Willow twig after det-ichment of the patches of Crypiomyces in autumn, (v. Tubeuf del.) black apothecial cover underneath the epidermis. On rupture of the epidermis, black apothecial cushions emerge and cover large areas of the living twigs. Eain causes the apothecia to become gelatinous, and to swell considerably ; on drying the cushions roll up and fall off, leaving scars in the bark (Figs. 132, 4). 248 ascojniycetes. A longitudinal section through a cushion exhibits a thick hypotheciuni, consisting of a close pseudoparenchyma of hyaline fungal colls, which permeate every tissue of the bark and cause death of the cambium ; above this comes a looser layer with many air-spaces, and over this the layer from which the asci and paraphyses arise. The asci contain eight oval unicellular spores with distinct cell-nuclei. When a section is placed in water, a very evident swelling takes place, and the asci elongate to twice their original length. I have not observed ejaculation of spores, but rupture of the asci occurs in water-preparations and the spores are set free in large numbers. The spores probably germinate and infect young shoots, the mycelium hibernating there. The effects of this fungus are death of diseased twigs of willow above the spot where a sporogenous cushion is formed. This species is also said to frequent Cornvs in America. Cryptomyces pteridis (Eebent.) occurs on fronds of Ptcris aquilina, but whether a parasite or not is as yet uninvestigated. The asci ripen after the fronds have passed through the winter. To this belongs the conidial form Fusidium pteridis Rabh. Clithris. The apothecia, at first spherical, become oblong, and break through the superincumbent layers by a lobed fissure. The apothecial disc is oblong and flat. The club-shaped asci contain eight hyaline spindle-shaped or thread-like spores, with one or more cells. The paraphyses are thread-like. The majority of this group are saprophytes. Clithris (Colpoma) quercina (Pers.) (Britain). According to Schroetcr,' this causes disease and death of living branches of oak. The oblong apothecial discs are greyish-white, and covered at first by a brownish-grey wall which, later, becomes ruptured. The ascospores are simple. Cylindrical pycnidia, with somewhat l)ent conidia, are also produced. CI. juniperi (Karst.) occurs on living twigs of juniper. Nothing is known of its parasitism. ' .Schroeter, Pilze Schlesiem, 1893. 249 Dothiora. The spherical apothecia are embedded in the substratum, which they rupture into lobes, while they themselves dehisce by irregular fissures. The club-shaped asci contain eight colourless or yellow, club-shaped or spindle-shaped, multicellular spores. Paraphyses are never present. Dothiora sphaeroides (Pers.) is regarded by Eostrup as the cause of a disease of the Lombardy poplar (Pojndi/s 2)i/ramidalu), in which the branches, particularly those of the upper part of the tree, die one after another till all are gone. The spores are club-shaped and constricted at the middle ; each half is divided by four or five cross-septa, and each cell so formed is again subdivided by a longitudinal septum. Vuillemin ascribes the same disease to Didyviosphacria pojndina Yuill. (see p. 218). According to Eehm, Du. spliacroidcs also occurs on Popidus tremida, and is distinguishable from Do. imUila (Fr.) on both Populvs italica and P. trcmnUi. Heterosphaeria. The spherical apothecia are at first embedded, but later emerge through the covering layers and dehisce, their apices breaking up into teeth-like lobes : they are dark-brown or black in colour. The asci are club-shaped and contain eight spores, which are colourless, oblong or club-shaped, and consist of one, two, or four cells. Iodine colours the pores of the asci blue. Tlie paraphyses are colourless and thread-like. Heterosphaeria Patella (Tode). (Britain and U.S. America.) The asci contain eight bicellular spores. The paraphyses are thread-like and septate, some being forked or branched ; they bear scalpel-shaped conidia. The mature apothecia are found chiefly on the stems of various UmbcUifcrac, e.g. Dcmcus Carota, Anethum graveolens, Petroselinum, sativum, Pastinaca, etc. A variety alpestris occurs amongst the mountains on Heraclcum Sp)hondylmm, also on Gentiana lutea, Vcratrum viride, etc. liehm and others believe that the fungus attacks living green parts of plants, and reaches maturity in the following year on the killed organs. !50 ASCOMYCETES. Scleroderris. A black stroma is formed in the bark of twigs attacked by this fungus, and thence the apothecia break out in great numbers, at first as closed spheres, later as stalked open cups with finely lobed rims. The asci are cylindrical or club- Fio. 134. — HcUroderris fiUiginosa on living twig of Salix alba. A, Three apothecia, two in section, the third seen from above, showing the cross-like fissure. B, Sections of diseased branches, whose growth has been arrested in the shaded parts ; on the dead bark apothecia are present. (', Asci, spores and paraphyses. (v. Tubeiif del.) Fic. 183.- -Scleroderris full- qiHosa on living twig of Salix Caprea. (v. Tnbeuf del.) shaped, and contain eight colourless spores which are club- shaped, needle-shaped, or thread-like, and divided by septa into four to eight cells. The pores of the asci are coloured blue by iodine. The paraphyses are thread-like. SCLERODEKRIS. 251 Scleroderris fuliginosa (Fries). (Britain and U.S. America.) This was considered to be a saprophyte till my attention was directed to its injurious nature. It occurs on living branches of Salix Caprm, S. triandra, S. alba, etc., and brings about their death. The black crusts, on which the apothecia develop, appear both on weakly twigs and strong branches. The my- celium makes its way through the tissues to the cambium, which it kills, causing this and neighbouring parts to become brown. Adjacent parts, as yet unattacked, continue at first to grow in thickness, but they too are gradually killed. As a result, the twigs attacked grow irregularly according to the extent and number of diseased places (Fig. 134); and when all or most of the lower tissues of a twig are killed, the higher parts die off with their leaves. Wherever the fungus appears, many ttees are generally attacked. Sc. aggregata (Lascli.) develops on the living stems of Rhinanthaceae and matures on the dead. Sc. ribesia (Pers.) is a common species on twigs of red and black currant, but whether parasitic or not is unknown. (2) DERMATEACEAE. The apothecia are developed at first either under the sub- stratum or altogether superficially. The ascogenous layer extends over a thick hypothecium. The Dermateaceae contain the Cenangicae, Dermatcac, Patel- lariaccae, and Bidgariaccae. CENANGIEAE. Apothecia at first embedded, then exposed. They are sessile, clavate or cone-shaped, and broaden out to discs on opening. Cenangium. Apothecia globose ; on dehiscence at first cup-shaped, but afterwards flatter and more saucer-shaped, with entire margins ; they may occur singly or massed togethei'. The club-sha]3ed asci contain eight colourless, oblong, unicellular spores, and filamentous paraphyses with thickened apices. Cenangium abietis (Pers.). (Britain and U.S. America.) This fungus is usually a saprophyte, but Thiimen suggests it as an 252 ASCOMYCETES. occasional parasite. Schwarz^ lias recently described it as attacking pines, weakened by an impoverished water supply to the twigs and by other unfavourable conditions. It appeared for a time as an epidemic in the pine forests of Germany, but very soon disappeared again. The symptoms of disease were, withering of twigs in spring from the apex downwards into the region several years old. The epidemic had been previously noticed in the spring of 1892, and was described by Hartig, who, along with Kienitz, regarded it as a result of the long dry preceding winter. The disease has never been observed on pines under five years old, and serious injury only results when the fungus is accompanied by damage done by insects. The apothecia containing the asci are generally produced only on dead twigs and needles. Schwarz regards as a conidial form of this species, Brun- chorstia destruens Erikss., which will be described in greater detail amongst the " Fungi imperfecti." In addition to Brvn- cliorstia, other pycnidia with unicellular conidia occur. DERMATEAE. The apothecia, at first spherical and embedded in their host, break out in clumps; they are generally short and thick-stalked, and open to form a roundish saucer-shaped disc with an un- broken rim. The hypothecium is thick and often coloured. Dermatella. A stroma is developed under the bark of tlie attacked parts of the host, and in it originate dark brown apothecia with short thick stalks. The bark is ruptured and the apothecia emerge as flat, expanded, saucer-shaped discs with a complete rim. The asci are club-shaped and thick-walled. The spores, at first unicellular, later multicellular, are large and colourless or brownish. The paraphyses are septate and generally forked ; they often form a coloured epithecium. Dermatella prunastri (Pers.) (Britain and U.S. America). According to Ludwig, this lives as a parasite on the living bark of plums, apricot, sloe, and other species of Primus. ^Schwarz, Die ErhrankuiKj d. Kief em (lurch Cenangium abietis, Jena, 1895. DERMATELLA. 253 Apothecia and pycnidia {Sjohacroncma spurium Fr.) are both developed. The ascospores are one-celled and hyaline. [Wagner' adds the following species found by liini in Saxony as more or less marked jtarasites : (Edit.) Dermatea (Pezicula) cinnamomea (Pars.) on QuercHs. It attacks the rind in places injured by deer, and causes injury to the trees. D. (Pez.) carpinea (Pers.) kills many young hornbeams ; it probably obtains entrance through wounds. D. (Pez.) acerina Karst. is a doubtful parasite on Acer Pseiidoplatanus.'] BULGARIACEAE. Bulgaria polymorpha Wett. {B. inquinans Fr.) (Britain and U.S. America). A dangerous enemy of the oak,^ causing death. Researches into its parasitism are still wanting. The sporocarps develop on dead bark, especially of beech. (3) PEZIZEAE. The apothecia are never embedded, but appear as saucer- or cup-like structures on the substratum ; they are fleshy or waxy, and often of bright colour. The hypothecium is very strongly developed. The families included in this group are : Mollisieae, Helotieae, Eupezizmc, and Ascoboleae. Of these, all except the last con- tain parasitic forms. The Mollisieae and Helotieae contain also a number of lichen-fungi not considered of sufficient practical value to be included here. The Ascoholeac live as saprophytes on animal droppings. MOLLISIEAE. The apothecia generally sit free throughout their whole existence on a close, firm substratum of hyphal tissue, or they' may be sunk in the host and break out later ; they are at first closed and spherical (rarely tapering downwards), but after- wards open and expose a cup-like, saucer-shaped, or flat disc of asci. The disc is waxy and soft ; externally it is brownish and generally smooth ; exceptionally it may be downy or beset with short hairs or bristles. The sporocarps are brown and com- ' Zeifsch. /. Pflanzenh-anhheiten, 1896, p. 76. - Ludwig, Centralblatl f. Baderiologie. u. Pai-asitenkunde ; also, Lehrbuch d, niederer Ki~ypto(jamen. 254 ASCOMYCETES. posed of psoiulopareuchyiua, which, towards the margins, becomes more elongated and prosenchymatous. Hypothecium generally poorly developed. Mollisia. The sessile brownish apothecia on opening generally exhibit a flat, saucer-shaped, transparent stratum of asci. The spores are unicellular, hyaline, and spindle-shaped or club-like. The paraphyses are hyaline or coloured, sometimes forked. Mollisia Morthieri (Sacc). The apothecia are developed on yellow spots of the lower epidermis of living leaves of Buhus Schleicheri and R. fruticosus. The young apothecia are reddish- brown and spherical ; when open they form yellowish-brown discs with very delicate margins. The asci contain eight spores, arranged in two rows. The spores are unicellular, club- shaped, and colourless. The paraphyses are colourless or brownish, with slightly bent points. Niptera. Apothecia as in Mollisia. The spores, however, on com- pleting their development are two-celled. Niptera hypogaea (Bres.).i Found by Bresadola in Southern Tyrol, underground on the roots of Adenostyles alhifrons. The apothecia are massed together on brown hyphae in blackened parts of the host-roots. The ascogenous disc is greyish-brown or whitish, with fine fibrous margins. The asci are spindle- shaped, and contain eight spindle-shaped colourless spores, which are at first one-celled, later two-celled. The septate colourless paraphyses are forked. Pseudopeziza. The members of this genus live as parasites in the leaf- tissue of higher plants and produce dead brown spots, in which the ascocarps are afterwards developed. The apothecia have delicate walls, and, after rupturing the epidermis, emerge as delicately-coloured saucer-like hymenial discs. The club- shaped asci contain eight spores, arranged in two rows. The 1 Bresadola, Fiiiuji trident, A. Lxxv., Fig. 1. pseudopp:ziza. 255 spores are ovoid or elliptical, colourless, and uuieellular. The colourless paraphyses have thickened apices, rarely forked. ^^-^ Pseudopeziza (Phacidium) trifolii (Bernh.). Leaf-spot disease of the clover. This disease appears on the leaves of various species of clover in Europe and America ; its attacks may attain considerable severity, and inflict great injury to crops. The leaves become spotted, and finally die off. The apothecia occupy brownish-yellow discs on the surface of the leaf, and hence are not unlike pustules of a Puccinia. The asci are club-shaped, and contain eight ovoid, unicellular, colourless spores. The paraphyses have broadened apices, rarely forked. A conidial form {Spliaeronema i^hacidioides Desm.) is generally allocated to this species. Ps. trifolii [var. medicaginis) (Lib.) is found on species of Medicago (Britain and U.S. America). Ps. bistortae (Lib.). This occurs on the lower epidermis of living leaves of Polygonum Bistorta, and F. viviparum, causing dark-brown swollen s2)ots where the apothecia are developed. Juel ^ has transferred this species to the Phavidiaceae, and named it Pseudorkytisma bistortae (D. C). Ps. alismatis (Phill. et Trail) causes spots on leaves of Alisma Plantago (Britain). Fabraea. This genus is distinguished from Pseudopeziza by the spores, which, though at first unicellular, become two or four-celled. The species are parasitic in the leaf-tissue of higher plants. Fabraea astrantiae (Ces.). The mycelium lives in the leaf- parenchyma of Astiuntid major and A. carniolica, causing dead spots. A form occurs on Saniada europaca. F. ranunculi (Fries.) (Britain). The apothecia of this are very common on brown spots on the leaves of various species of Panuneulvs. F. cerastiorum (Wallr.) frequents leaves of Cerastium (Britain). F. Rousseauana (Sacc. et Bomm.) occurs on leaves of Caltha palustris. (A British species if synonymous with Pseudopeziza calthae Mass.). Beloniella. The gregarious apothecia are at first embedded, but break out later. Externally the apothecial discs are rough, dark brown, ^ MykoL Beifr. Vetemk.-Akad., 1894. 256 ASCOMYCETES. and striped, the margin being fibrous. The asci contain four to eight spores. The spores are generally ovoid or spindle- shaped, at first unicellular, but divided later into two to four cells by means of cross walls. The colourless paraphyses have thickened club-like apices. Belionella Dehnii (Rabh.).^ This parasite covers stems and leaves of Pokntilla norvegica, and is distinguished by its sharp, spindle-shaped, bicellular spores. HELOTIEAE. The apothecia are generally quite superficial ; less commonly they are at first embedded, and emerge later; or they may develop from a sclerotium. In form they are spherical, cup- shaped, or top-shaped, and a stalk of some kind is generally present. On opening, they form a cup or flat plate, on which the hymenium lies exposed ; the cup is soft or w^axy, and enclosed in a delicate wall, which is externally either smooth or hairy. The sporocarps consist of a pseudoprosenchyma (after Eehm). Sclerotinia. The sclerotia - give rise to smooth-stalked ascocarps with the form of beakers, funnels, or saucers. The stalks often produce rhizoids. The asci contain eight unicellular hyaline spores, elliptical or spindle-shaped, and of equal or unequal sizes. The paraphyses are thread-like. In several families conidia are formed before the sclerotia. Some forms are heteroecious. Most of the species are parasitic on plants. The Sclerotium diseases of the Vaccinieae.^ These are a well-known group of sclerotium diseases, and amongst them the following have been named as species. Sclerotinia vaccinii Wor. {8d. Urnula Weinm.). The sclerotium disease of the cowberry. The young shoots and ^Figures in Heciwigia, ISfSl. -Literature: I)e Bary, " Uebereinige Sclerotien u. Sclerotienkrankheiten," Botau. Zcitunij, 1886; also ilorphology and Biology of (he Fungi, English edition. Brefeld, Schimmelpilze, Heft. iv. u. x., and Botan. Zeifung, 1876. .Saccardo, Sylloge, Vol. vm. •' Woronin,il/(^?n. deVacadem. imp6r. d. sci. d. St. Petersburg, vii. Ser. , t. 36, 1888 (with ten plates) ; also Berichte d. deiitsch. botau. Ges., 1894. SCLEROTINIA. 257 leaves of Vaccinium Vitis-Idaca exhibit in spring a mould- like coating, consisting of chains of lemon-shaped conidia. Woronin thus describes it : " In the outer layers of the cortex, amongst the dying elements, a pseudoparenchymatous cushion is formed, from which simple or dichotomously branched hyphae grow out through the overlying cuticle. The individual members of the chains of conidia are separated from one another by a spindle-shaped piece of cellulose — 'the disjunctor.' " The disjunctor spoken of here is a spindle-shaped cellulose body found between the single conidia ; it easily breaks across and so facilitates the breaking up of the chains of conidia Fio. 135. — Sclerotinia vacciniion Vacciaium VUis-hlaea. Mummified Cowberries in fresh condition and in the following May, after development of Peziza-cw^s. A, Chain of conidia united by disjunctors. B, Germinating conidium after treat- ment with iodine ; the plasma has shrunk, but remains connected with the sporidia in process of abjunction. (After Woronin.) (Fig. 135). It has its origin as follows: The conidia at first lie closely end to end, enclosed in a delicate primary membrane ; the partition-membranes split into two lamellae, each of which takes part in the formation of a cellulose body which gradually becomes spindle-shaped. In the course of its growth this cellulose body — the disjunctor — ruptures the primary enclosing membrane, and, being released, becomes more elongated, so that the conidia are pushed away from each other and fall apart. The conidia have a strong characteristic odour of almonds, attractive to insects, which carry off the conidia and dust them on the stigmata of other Vaccinium flowers. Wind is also, in all probability, an agent in the distribution of the conidia. The R 258 ASCOMYCETES. coniclia germinate and give off long septate hyphae which, follow- ing the course of the pollen-tube, reach the ovary, and soon fill all four loculi with a white mycelium. The growth of this mycelium proceeds from the central axis towards the walls, and forms a hollow sphere open above and below. The diseased berries cannot be distinguished till ripe ; then, whereas the normal are red, the diseased are yellowish-brown to chestnut- coloured, and soon shrink up, leaving only the outline of the sclerotiuni. The dead or mummified berries fall prematurely, and lie over winter on the earth. In April or IMay, the sclerotia give rise Fig. ISe.— Sclerotinia oxycocci on Vacciniimi Oxycoccv.s. Young shoot of Cran- berry with mature conidial cushion and diseased upper leaves. A, Feziza-cxn^ developed from a sclerotial fruit ; numerous rhizoids proceed from the base of the stalk. B. Ascospores in stages of germination. C, Conidia in germination, witli remains of di.sjunctors still attached. (After Woronin.) to several primordia or horn-like stalks, on the extremity of which an apothecium is afterwards formed. Rhizoids are pro- duced at the base of the stalk and attaching themselves to the ground act as supports and organs of nutrition. The apothecia contain both asci and paraphyses ; the latter are septate, dichoto- mously branched filaments, with club-shaped ends, and coated with a brown resinous substance. The asci have a canal at one end through which are ejaculated eight spores of almost equal size. These produce sporidia in water; in nutritive solutions, however, they form a septate mycelium with conidia. The ascospores bring about infection by means of one or two germ-tubes wliich penetrate the outer membranes of young SCLEROTINIA. 259 cowberry shoots, the stomata being always avoided. In less than three weeks conidia are produced. The mode in which the germ-tubes attack the host-plant is very remarkable. Woronin says : " The gerra-tubes developed from the ascospores grow inwards towards the vascular bundles of the host-plant and enter them ; then they continue to develop, but now in the opposite direction from the interior of the plant towards the periphery. Here a peculiar phenomenon is exhibited, the fungus exerts its injurious effects on the surrounding tissues of the host-plant, then, having killed these, it utilizes Fio. 137. — Sderotinia haccarwn on Vo.ccinium Myrtillus. Young shoot of Bilberry with deformed branch bearing white conidial patches on its lower side ; also a withered leaf. A, Conidial chains, and a portion enlarged. B, Shoot with aii upper healthy ripe berry and a lower mummified one. C, Peziza-cup developed from a sclerotium. D, Ascospores ; the smaller incapable of germination, another germinating and giving off sporidia. (After Woronin.) them as food-material." " Finally, the germ-tubes penetrate between the elements of the outer rind already killed, and there develop to a stroma-like cushion of large-celled pseudo- parenchyma from which the chains of conidia emerge through the ruptured cuticle." (Saccardo also mentions Scl. oreophila Sacc. on leaves of Vaccinnim Vitis-Idaea.) Sclerotinia oxycocci Wor. The sclerotium disease of the true cranberry ( Vaccinium Oxycoccus). The spores of this species are smaller than those of the preceding; each ascus contains four 260 ASCOMYCETES. larger and four smaller spores, the latter appearing to be rudi- mentary and incapable of germination. Scl. baccarum Schroet.^ (Britain).^ The sclerotium disease of the bilberry ( Face. Myrtillus). This varies from the other species in having round conidia incapable of germinating in water, in having more robust apothecial beakers, and in lacking rhizoids. The spores are similar in number and arrangement to the preceding species. Scl. megalospora Wor. The sclerotium disease of the crow- berry {Umpdnim nigrum). This species is distinguished by the Fio. 138. — Sclerotinia -megalospora on Vaceinimn vMginosum. Partially withered leaf with a white conidial cushion on the mid rib. A, Conidial chains produced on a mycelium, resulting from an artificial culture of ascospores in plum-solution. B, Isolated conidium with remains of disjunctors still attached. C, Twig with upper mummified berry. E, Ascospores ; one in its gelatinous envelope, the other giving off a germ-tube and sporidia. (After Woronin.) form of its conidia, and the manner of their germination ; in the form of the sclerotium, and the absence of primordia ; in the absence of rhizoids ; and, particularly, in having large ascospores almost similar to each other. The " white berries " of the Vacciniaceae are distinct from the mummified berries caused by Sclerotinia.^ Scl. aucupariae Ludw. The mummified fruits of Pyrus Aucuparia, resulting from this fungus, were first observed by 1 Schroeter, Hedivir/ia, 1879 ; Woronin (loc. cit. ). - Sclerotia of this species have been found in Hcothmd by Professor Traill. ^Magnus and Ascherson, Berichte d. deutuch. hotan. Ges., 1889; also ZooL- botan. Ges., Vienna, 1891. SCLEROTINIA. 261 Woronin ^ in Finland, and later by Ludwig in the Erz mountains. The ascocarp developed from the sclerotia has no rhizoids. The ascospores infect leaves, and there the conidia are produced. Scl. padi Wor. Causes mummification of the fruits of Pruiim PadiLs. Woronin regards Monilia Linliartiana Sacc. as belonging to this Sclerotinici. Woronin also considers the conidial form Monilia cinerea as related to the mummified fruits of cherry. Ovularia nelans on Mespilus is probably also a form of some Sclerotinia. A Sclerotinia occurring on Cotoneaster nigra produces mummification of the fruit, and forms conidia on the surface. Monilia fructigena of the apple, pear, quince, plum, peach, etc., is in all likelihood a form of some Sclerotinia, although the ascus-form is still unknown (see also " Fungi imperfecti "). Scl. betulae Wor. (U.S. America). This sclerotium of the birch-fruit was discovered by and briefly described by Woronin in 1888. Nawaschin 2 has recently re-investigated it, and named it the " birch-catkin disease." It is found on the green catkins in June. The fruits containing sclerotia are obcordate in shape, instead of the normal elliptical form with both ends acute ; the wings are similar to those of healthy seeds. The sclerotium is composed of a very hard white pseudoparenchyma, which passes in the form of a horse-shoe round one side of the apex of the fruit (Fig. 139). The outer layer is black and very firm. Sclerotia placed on moist sand produced ascocarps at the beginning of May. Development in the open also takes place about this time. In the birch forests near St. Petersburg this disease is common, and birch-catkins containing sclerotia may be found abundantly amongst fallen leaves about the mouth of May. From each sclerotium there are produced one or two ascocarps, with rhizoids and stalks of a length varying with the depth of dead leaves on the ground. The apothecia are at first funnel-shaped, but later became saucer-shaped and l-4mm. broad, with a golden or fleshy colour. The asci contain eight spores which are forcibly ejaculated, and if a handful of damp birch leaf-mould is thrown up into the air 1 Woronin, Berichte d. deu/sch. hotan. Ges., 1891; also M^m. de I'acad. imp. d. svv'. de St. Petersburg, 1895. With five plates. -Nawaschin, Sclerotinia betidae, Wor. Russian brochure with four coloured plates, 1893. 262 ASCOMYCETES. a cloud of spores so ejected may easily be seen. Infection takes place on the birch flowers. It is possible to promote germination in water and on moistened leaves, but the germ- tubes soon die. This disease, on account of the small size of the birch fruit and the tiny sclerotia, remained for a long time quite un- observed, yet it seems to be common everywhere ; in Russia it has been found frequently, also in Germany, North America, and Japan. It possesses considerable economic importance, since diseased seeds are no longer capable of germination. Fig. 13Q. —Sckrotinia betulae. a, Birch fruits with sclerotia, which have germinated and formed cup-like apothecial discs ; rhizoids have developed on the stalks, h, Birch fruit, somewhat enlarged, with semilunar sclerotia. (After Nawaschin.) Hormomyia betidae Wtz. often occurs along with the above. It causes the production of thick spherical fruits with little or no wing. Sclerotinia adusta Karst. has also been found on birch leaves in Finland. Scl. alni Naw. Woronin found this first on catkins of Alnus incana. Nawaschin has more recently investigated it.^ Scl. rhododendri Fischer.^ This was first discovered by Fischer in 1891 in fruits of the Alpine-rose {Rhododendron ferriLgineum and R. hirsutum) in Switzerland. It has since been observed in various parts of Switzerland and the Tyrol. 1 Nawaschin, Berirhte d. deutsch. hotan. Ges., 1894; Maul, Hedwiqia, 1894, p. 213. With two plates. -E. Fischer, Nalurforsrh. Ges. Bern, 1891 ; also Berirhte d. schiceiz. hotan. Ges., 1894. With figures. SCLEROTINIA. 263 Fischer succeeded in obtaining stalked ascocarps from sclerotia of one and two years old. They resembled most closely those of Scl. vaccina, their stalk being provided with numerous rhiz- oids. The asci contain eight similar spores which germinate directly on ejaculation. They develop a mycelium and, later, chains of chlamydospores which separate by means of disjunctors. The little conidia found by Woronin on Vaccinium are never produced. The paraphyses are generally unbranched and corre- spond in length to the asci. The mummified fruits are easiest found after the healthy capsules have dehisced, then the diseased ones remain closed. In winter the healthy capsules remain attached to the plant, the diseased fall off. Seeds of diseased capsules are completely overgrown by hyphae. Wahrlich ^ found sclerotia in capsules of Rhod. daJmricum from Siberia. They gave off a sclerotial ascocarp with a stalk devoid of rhizoids. The mummified fruits resemble closely those of Sd. rhododmdri. Scl. heteroica Wor. et Naw. = Scl. ledi Naw.- occurs on Ledum jMltistre in Faissia and Finland. It is very similar to Scl. rhododendri, but is distinguished by the paraphyses being swollen and frequently forked at the end. In nutritive gelatine a copious mycelium is developed, and produces chains of ripe conidia with tiny disjunctors. Woronin found that these conidia are produced only on Vaccinium idiginosum, never on Ledum ; but the conidia so formed can successfully infect the ovary of Ljcdum. We have here the first known case of heteroecism outside the Uredineae. Scl. sclerotiorum Lib.^ (Britain and U.S. America). The sclerotia of this fungus are found in many various plants. They fall to the ground with the dead plants, hibernate under snow, and on the arrival of warmer weather in spring give rise to several stalked apothecia. The ascospores are ejaculated from the asci, germinate, and produce a parasitic mycelium, described thus by De Bary : " The ripe spores of Peziza sclerotiorum produce germ-tubes on any moist substratum. ^ Berichte d. deiif.frh. hotan. Ges., 1892. -Nawaschin, Berichte d. deutsch. hotan. Ges., 1894, p. 117. ■' Bi-efeld, Schimmelpilze, iv. and x. ; De Bary, Morphology and. Biolo< botav. Jahrhwh, 1889, p. 123. 282 USTILAGINEAE. attacks the axis of the maize-hfads. Its spores are spherical with slightly granular coats, and measure only 4-6/a in diameter. It causes damage through shrivelling up of the grain. Ust. Reiliana Kiihn. This smut frequents Sorghum halcpcnse and >S^. n/If/arr (Durra or Indian millet); also maize in various parts of Europe and America/ as well as in Egypt and India. It is called " Haniari " in the Arabic language. Kiihn ^ thus describes it : " This species causes the ears of Durra to become large smut-galls of roundish or ovoid shape, with a height of 60-95 m.m. and a diameter of 40-60 m.m. At first the smut is enclosed in a whitish skin, which is ruptured into shreds to allow the escape of the black spore-powder. After the smut-spores are shed, there remains a stiff skeleton consisting of the fibrovascular bundles of the aborted ear." The spores are distinguished from those of ITst. maydu by their greater size (9-15/>i), and their almost smooth membrane with very small spines. According to Brefeld, the spores are capable of germination in nutritive solutions after eight years. In the fresh condition they germinate in water to a limited extent, producing multicellular promycelia which give off conidia. In nutritive solutions they germinate and produce thick promy- celia with three or four cells, from which multitudes of conidia (5-1 2yu long and 3-5^ broad) are abjointed. The conidia fall off and sprout till the nutritive substratum is exhausted, when they give rise to thread-like conidia which do not coalesce. If kept dry the conidia easily retain their vitality for months. Kiihn distinguishes further Sorosporium Ehrenbergii Kiihn on Sorghvm cermmm. Ust. cruenta Kiihn.^ Another parasite on the ears <-)f Sorghum. It is described by Kiihn as follows : " On the s pikelets little reddish-brown protuberances of roundish or oblong shape are formed and enclose moderately-sized masses of dark-red smut-powder. If the pustules are very numerous they coalesce with each other, and the branches of the ear become more or less shortened, thickened, and twisted. Where ' Norton, " Ustilago Reiliana," Botanical Gazette, 1895, p. 462. - Kiihn, "Die Brandfornien der Sorghum-arten," Mittheil d. Ver. /. Erdhnuh' zu Halle, 1877. ^ Kiihn (lor. cit.) and Hamhurqer Garten- Zeitung , Bd. 28. Brefeld, Heft v., p. 91. USTILAGO. 283 the pustules are fewer in number the parts of the ear retain their normal position, but all the floral organs contained in the glumes are wholly or partially converted into irregular greyish smut-masses. Isolated pustules may occur under the inflorescence, on the next internode of the haulm." Pio. 153. — Ustilago cruenta. Smut of limi i .r -Mi-luim. The head has been divided up and the isolated branches phi a : i: i I iju ovaries are transformed to long crooked sacs, and pustule-like out ur i~o present on stalklets and stalks, (v. Tubeuf phot, from material supiJu .1 Ir, I'lof. Dr. .lul. Kiihn.) The spores are yellow to brown in colour, smooth-walled, and of very variable shape, 5-12/ii long and 5-9/x broad. As a rule, germination in water results in the formation of a germ- tube composed of four or five cells, which elongate to long mycelial threads or, exceptionally, produce a single conidium. As a result of germination in nutritive solutions, a lively 284 USTILAGINEAE. tbrination of conidia ensues ; the conidia multiply in a yeast- like manner, and only grow out as hyphae on exhaustion of nutritive material. Infection takes place on seedling-plants. Kiihn cultivated this species on Borghimi saccharatum and S. vulgare., and suggests that a common disease of Durra in South Africa may be caused by this parasite. Ust. sorg-hi (Link.) {Ust. Tulasnci Kiihn) (U.S. America). This is another widely distributed parasite of Sorghum vulgare and >S'. saccharcdniii. Its external appearance is described by Kiihn somewhat as follows : " Diseased plants attain to almost their normal size, and the flower-head is developed as far as the glumes. The ovary, however, is completely metamorphosed into a sac iilled with spores, its outer wall forming a delicate Fio. 154. — Ustitago cruenta. Spikelet enlarged from a head of Sorghum. The ovai-ies are transformed into long flask - shaped sacs, from slits of which the spores are emerging as a black powder. 1 natural size. (v. Tubeuf del.) Fig. 155. — Ustilago cruenta. Germin- ating .and sprouting conidia from a cultivation in plum-gelatine, (v. Tubeuf del.) whitish coat, which is easily torn, and, when the spores have escaped, a columella will be found to occupy the centre of the smut-mass. The stamens may also become filled with spores, and be externally more or less irrecognizable. As a rule, all the flowers of a head are smutty; if any escape, they remain more or less rudimentary." The spores, according to Brefeld, germinate only in nutritive solutions. They produce a four-celled promycelium, on which few conidia are formed. Ust. sacchari llabh. Dust-brand of cane sugar. This fungus injures the stems and heads of Saccharum officinale, S. ci/lindricum, and S. Erianthi in Italy, Africa, and Java. Ust. sacchari-ciliaris Bref. occurs on Saccharum ciliare near Calcutta. Ust. avenae (Pers.). The smut or brand of the oat occur.s USTILAGO. 285 very frequently on Avena sativa, also on Avena orientalis, A. fatua, and A. strigosa in Europe and Xorth America. So common is it that one seldom sees a field of oats free from the black smutted ears (Fig. 156). All parts of the flower are attacked, the ovary, stamens, glumes, and even the awns. The grains become filled with the black spore-powder, which shows through the transparent Fig. \b6.~Ustilago avenae. The Oat-smut on Avena sativa. (v. Tubeuf phot.) membrane of the ovary wall. The diseased ears emerge from their enclosing leaf-sheaths, and become exposed to wind and rain, under the effects of which the delicate membrane soon becomes ruptured and the spores are blown or washed away, till only the axes of the spikelet are left with a few ragged remains of the flower. As a rule every shoot of a plant and all the grains of an ear are attacked ; if single grains do escape, they remain poorly developed. The spores (5-8^) have a smooth or slightly granular coat, and 286 USTILAGINEAK. retain their capacity for Li'erniination for years, lu water they germinate immediately, and produce a single (rarely two) promy- celium consisting of four or live cells, from the ends or partition- walls of which oblong conidia continue to be abjointed for about two days. The cells of promycelia may become connected with one another by lateral branchlets. Delicate germ-tubes are given off by the promycelial cells, by the conidia, or by secondary conidia. In nutritive solutions, on the other hand, the spores germinate much more vigorously, the promycelium is stronger, the conidia are continuously abjointed from little sterigmata, and go on sprouting in a yeast-like manner till, on exhaustion of the nutriment, they germinate to form vigorous mycelial filaments. The fusion of the cells of promycelia never takes place in nutritive solutions. The infection of oat-plants takes place on the soil by means of the germ-tubes produced from the conidia, promycelia, or spores.^ These infect the first leaf-sheath— that one which on germination emerges from the ruptured seed-coats as a whitish or yellowish- green shining shoot, and continues to grow as a sharp-pointed cylinder till, pierced by the first green leaf, it dries up. In 36 to 48 hours after infection, mycelial threads were found to have pierced the epidermal walls, and to have branched freely in the tissues. The mycelium grows from the leaf- sheath into the first green leaf, passes straight through it into the second, and so on till it reaches the haulm or stem." The young mycelium grows steadily onwards, and the plasma of older hyphae passes over into it. In this way the fungus keeps pace with the host-plant, exhibiting externally no symptom of its presence till the flowers are reached, where the chlamydo- spores are formed. Sterilization of seed-corn by Jensen's hot-water method is strongly recommended.^ In America, steeps containing potassium sulphide, copper sulphate, or lime are also used. As preventive against infection, late sowing is advisable. This is founded on Brefeld's investigations, in which he found that oat-smut germin- iWolf, Der Brand ties Getraides, 1874. ■^According to Kuhn, and in Brefeld's infections (Heft xi., 1895), the majority of the germinating conidia are said to penetrate into the young shoot-axis. ='" Treatment of Smuts of Oats and Wheat," 6'. 5". Department of Arjricidtnrt, Farmers' Bulletin No. 5, 1892; "Grain-smuts and tlieir prevention," Yearbook of U.S. DejJt. of Agriculture, 1894. USTILAGO. 287 ated best at 10" C, and not so well above IS^'C. This conclusion is supported by experiments of Kellermann and Swingle. Xeither these investigators nor Jensen, however, agree '^, Fio. 157. — Ustilago perennans on Arrhenatherum elating (Oat grass). The grains are transformed into black smut-masses ; the appearance of the infected spikelets is quite distinct from that of the healthy one to the right, (v. Tubeuf phut.) with Brefeld's view, that the fungus is introduced into fields with fresh farmyard manure. Kellermann and Swingle have found a smut on oats in America whicli tliey distinguish as Vst. avenue var. levis. Ust. KoUeri Wille. This is another species of oat-smut recently dis- tinguished ; it has smooth spores, and is said to cause even greater damage than Ust. avenae. 288 USTILAGINKAE. Ust. perennans liostr.^ This smut or dust-brand occurs frequently in the Howers of Arrheiiafhcnmi clatius (Fig. 157). The mycelium perennates in the rhizome. An Ustilago nearly allied to the preceding one occurs also on Fcdnca prateiisis, Lolium 'prrennc, and other grasses. The Smut of Barley. There are really two species of Ustilago found on barley, ¥ui. \i>^.— Ustilago perennans. Spore-culture Tj„f 7,,.,.,/,,; .,,-,,] JT^f ^,,i,]r, in plum-gelatine, (v. Tubeuf del.) ^ ^''- I^-OUIU ,inU Uhl. nUUa. Ust. hordei (I'ers.) {Ust. Jrmcni Itostr.) (Britain and U..S. America). This has black spherical spores (6*5 to 7"5ya in diameter), which germinate and give off conidia from a promycelium. The spikelets gene- rally remain enclosed in their coverings. Treatment of seed- corn with a half per cent, copper steep is a certain remedy. Ust. nuda (Jens.) (U.S. America). In ears diseased by this smut the epidermis of the glumes is early lost, so that the spore-powder lies freely exposed when the ears emerge from the leaf-sheath. The spores on germination give off' a four- celled promycelium, which however produces no conidia, but develops directly to a septate mycelium. The spores are smooth-coated and oval (5-7/>t long and 5-6'5yU broad); they are matured and set free at the flowering season of the barley, and probably infect seedlings in spring. The spores of this smut are very resistant against treatment with copper steeps, and it is recommended to soften the barley for several hours in cold water before applying Jenson's method. Ust. tritici (Pers.) (Britain and U.S. America). Wheat-brand. The spores are developed in the ovary of the wheat, and are black with a tinge of olive-green. On germination they im- mediately form a non-septate mycelium (Fig. 160). Heniiing '^ has described spore-cushioiis on tlie leaves and leaf-.slieaths of Triticum vulgare in Upper Egypt. Ust. buUata Berk, on Triticum orientale in Turkestan. ^ Rostrup, Udilaijineae Dauiae, 1890. -Heuning, Zeitschrift f. Fflanzenkraiilcheiten, 1S94. USTILAGO. 289 Ust. secalis Ifabenh. IJye-brand. This occurs but rarely, and destroys only the grain. Ust. panici-miliacei (Pers.) {Ust. destruens Duby). Sniut of Millet. This smut occurs on the flowers of Panicnm milici- Flfi. \h9.—Vstilac,o liordci. Barley-smut on Honleum distichum. (v. Tubouf phot.) ccum, P. chartafjiniense and P. Crus-r/aUi in Italy, France, Germany, and North America. Sometimes it is very abundant and causes great damage. The mycelium makes its way into young plants and grows upwards with them, penetrating' every T 290 USTILAGINEAE. shoot. Spores are developed only in the inflorescence, which in consequence fails to reach its full development as a panicle, and remains more or less spike-like and enclosed in a leaf- sheath. The parts of the inflorescence become completely filled Fi(!. 160.— Ustilago tritici. Wheat-smut. The central ear is normal and liealthy, the others are smutted and most of the spores ai'e already shed, (v. Tubeuf phot.) with a sporogenous mycelium from which arise the spore-masses ; these are at first enclosed in whitish coverings consisting of tissues of the host-plant, but when mature they escape as a black dust or powder. USTILAGO. 291 The spores are smooth-coated and spherical or elHptical, 9-1 2 /x long, and 8-10 fx broad. According to Brefeld, they germinate in two or three days in water, and produce proraycelia with four or five cells ; the cells may either bud out directly and become hyphae, or do so after previous fusion. Spores placed in nutritive solutions germinate in about three days, and produce several strong septate promycelia with spindle- shaped conidia. The conidia as a rule germinate directly into branching hyphae ; fusion of conidia is not known, and secondary conidia are only rarely formed. The hyphae become septate in their older parts, and produce conidia in two ways, firstly, from hyphae in the solution itself; secondly, from aerial hyphal branches which rise out of the solution and give off conidia in a manner similar to mould-fungi. Brefeld states that infection takes place by means of the germinating conidia. Only resting-spores are produced on the plant itself, and these retain their capacity for germination for years. Ust. Rabenhorstiana Kiihn^ (U.S. America). This is found on Panicum miliaccum, P. glabrum, P. linearc, and P. sanguinale. It destroys flowers, ears, and upper part of haulms. The spores are brown and spiny ; they germinate, but do not produce conidia. Ust. sphaerogena Burrill. An American species causing distortion of the spikelets of Panicum Crus-galli. The malforma- tions resemble those produced on the same host by Tohjposporium hullatum, but differ in having a rough surface with short rigid hairs. The spores are free and germinate easily in water, producing promycelia which give off conidia. The conidia frequently sprout for a time in a yeast-like manner. The following are American species : Ust. diplospora Ell et Ev. On Panicum sanguinale. Ust. trichophora Lk. On Panicum colinum. Ust. setariae Eabh. On Panicum sanguinale ; probably identical witli Ust. liabenhorstiana. Ust. panici-leucophaei Bref. On Panicum leucophaeum in Rio de Janeiro. Ust. digitariae Kze occurs on the flowers of Panicum {Dvjitaria) >>aii(juliialc, P. glahrum, and P. rcpois. The spores are smooth-walled. ' Kiilni, mibrifjia, 1876. 292 USTILAtilNEAE. Ust. panici-frumentacei Wrvf} is ibmul on Panicuvc ffumc/t- t an ton, a cultivated Himalayan millet. Only isolated grains in an ear are attacked, becoming enlarged to twice their normal si/e. Germination of spores takes place sparingly in water, l)ut abundantly in nutritive solutions. Two-celled promy- celia are produced bearing numerous sprouting conidia. On exhaustion of nutrition, the conidia give off one or two filaments on the surface of the liquid, and from these other sprouting conidia arise. Ust. Crameri Korn. completely destroys the ovaries of Sctaria ifidini, S. cii'idin, and S. amhigua, leaving only the outer wall as an enclosure for the spore-powder. The spores are brown, smooth-walled, and 6-9 /a broad, 10-12/x long. The proniycelia consist of four or five cells, which in water as well as nutritive solutions grow out into long threads without producing conidia. Ust. neglecta Niessl fills with its black spore-powder the ovaries of Sdaria glauca, S. verticillata, and >S'. viridis. The cells of the promycelium develop into a mycelium without pro- duction of conidia. Ust. Koiaczekii Kuhii. On Setaria geniadata in Berlin Botanic Garden. Ust. bromivora Fisch. (Britain and U.S. America). This appears in tlowers of species of Browns, so that the ovaries become filled with a dark-brown or black spore-powder, but the glumes or heads undergo no deformation. The spores are smooth, and on germination in water produce only a spindle- shaped one-celled (rarely two-celled) promycelium ; in nutritive solutions, Brefeld found they generally produced two-celled proniycelia, bearing conidia from wiiich are produced further proniycelia with conidia ; yeast-like colonies are never formed. Ust, ischaemi Fuck, attacks Androjjogon Ischaemum. The infiorescences remain almost completely enclosed in the upper- most leaf-sheath, and are destroyed except their axes. The spores are brown and smooth-walled. Brefeld states that in nutritive solutions they produce conidia which remain adherent to the promycelium and grow out into long hyphae witliout coalescing. Ust. andropogonis-tuberculati Bi'ef. on Andropogon tidjcrcidatum from Simla. Ust. andropogonis-annulati Bref. on Androjjngon annulatvra from Culcutta. ' Brefel.l, Sclu„nne/pi/:j\ Heft Xii., 189,-). USTILAGO. 293 Ust. grandis Fries. Iteed-smut. (Britain.) This frequents the hauhiis of Plirafjmites communis (also Typha latifolia and T. minor) ; the internodes of the host in consequence swell out and appear as if the stem carried one or more bulrush-heads. The mycelium permeates the whole host-tissue and produces spores, which escape as a lilack dust on rupture of the epidermis. According to Kiihn, the spores are capable of immediate ger- mination and retain their vitality for a whole year. A four-celled promycelium is produced and becomes detached from the spore ; then follows an abjunction of oblong conidia from the septa of the promycelium. In nutritive solutions, Brefeld found that germination took place in the same way, but more rapidly and vigorously. Numerous conidia are produced, but these only rarely give off secondary conidia, and then only a single one ; more conniionly they produce promycelia, as the spores did, and conidia again arise from these : yeast-like sprouting does not occur. The resting-spores may continue to give off promycelia in succession for some time. On ex- liaustion of nutrition the cells of the promycelium, as well as the conidia, develop into mycelial threads, to which alone Urefeld ascribes the capacity for infection. Ust. long-issima (Sow.) (Britain and U.S. America). Tliis forms elongated brown spore-patches on the leaves of various species of Glyccria. Brefeld states that tlie smooth spherical spores germinate in water, and give off a short unicellular promycelium which undergoes no further development. In nutritive solutions the spores germinate in like manner, but the promycelium becomes thread-like and septate, and gives off conidia laterally ; new promycelia continue to be given off from a cell which remains behind inside the spore, and tlie conidia ultimately develop into hyphae. Ust. hypodytes (Schlecht). This species forms dark smutty C(jatings on haulms and leaf-sheaths of Glyccria Jiuitans, Dip- /achnis fusca, Agropyrum rcpcns, Calamagrostis epigca, Psamma nimaria, Stipa pcnnatci and S. capillaris, Bromus erectus, Triticv.m i-i pins and T. vidgare, Elymus arcnarius, Panicum repeiis, Phrag- mitca communis, Arundinaria, etc. The spores are brown, smooth-walled, and irregularly spherical or quadrangular ; they germinate in water or nutritive solutions, producing mycelia direct, without previous formation of conidia. 294 USTILAGINEAE. Ust. grammica V>. et B. is re])orted on hauluis of Aira and (Jii/ceria in England. Ust. echinata Schroet. i)roduces sniut-strips on leaves of Phalarix arundinacea. (U.S. Amer.) Ust. cynodontis Henn. On Cijnodon Dactylon from Simla. Ust. arundinellae Eief. On Arundinella near Calcutta. Ust. aristidae-cyanthae Bref. On Aristida cyantha from Himalaya. Ust. coicis Bref. On Coi.v lacryma from Simla. Ust. esculenta Henn.^ causes deformation of plants of Zizania latifolia in Tonquin and Japan. The deformed parts are eaten, while the spores are used for dying of hair and eye-brows, as well as in the manufacture of a varnish. Ust. paspalus-dilatati Henn. On Paspalvs dilatatvs. Ust. olivacea D. C. frequents species of Cari\r. The olive- brown spore- masses hang loose and fleecy from the destroyed ovary. The spores, according to Brefeld, are produced from long hyphae which become thickened at intervals and broken up by cross-septa into portions corresponding to the future spores. The hyphae, however, are not completely given up to spore-formation, but parts remain and form fine filaments which give the fleecy appearance to the ruptured ovaries. Germina- tion in water results in the formation of a single conidium, a second being rarely formed. In nutritive solutions similar conidia are produced one after another successively, and sprout off conidia in a yeast-like manner without the formation of pro- mycelia. On failure of nutriment, hyphae are finally produced. Ust. Vuijkii Oudem. et Beyerk. The ovaries of Luzula campestris become filled with spores, some colourless, some light-brown. The spores germinate in water, giving four-celled promycelia with ovoid conidia, which do not, however, coalesce or develop further, even in nutritive solutions. Ust. capensis Bees. In fruit of Juncas. Ust. luzulae Sacc. In fruit of Luzula. Ust. scabiosae (Sow.)- (f/si!. /oscw/orM7M Tub). (Britain.) The anthers of Knaiilhi and Scahiosa attacked by this fungus become filled with a flesh-coloured to violet spore-powder, and swell to little sacs. The flowers otherwise are but little altered. Brefeld found that spores from Knaiitia arvensis germinate easily and abundantly in water, and produce promycelia con- ^ P. Henniugs, Hedwirjia, 1895; Miyuhe, Tohio Botanical Magazine, 1895. 2 Fischer v. Waldheim, Bof. Zeitnng, 1867. U.STILAC40. 295 sisting of three or four cells with coiiidia, and sometimes secondary conidia. Coalescence of conidia may take place, and thereafter production of little mycelial threads. In nutritive solutions everything proceeds more luxuriantly, and conidia are produced in large numbers ; they are easily detached and sprout Fio. 161. — Ustilago tragopogoiiis. Plants of I'mgopogon in flower and fruit— 1, normal fruit ; 2 and 3, normal flowers ; 4, two normal flower-buds. The remaining specimens are attacked by the fungus, and, in consequence, i-emain in the bud condition, and filled with black spores which escape by the opening of the involucre, (v. Tubeuf phot.) yeast-like, till, on deficiency of nutrition, fusion and subsequent germination takes place. Ust. intermedia Schroet. (Ust. flosmlorum D. C.) (Britain). The anthers of Scahiosa Columbaria become filled with the dark violet spores of this smut. The spores germinate in water, and, according to Brefeld, produce three-celled promycelia with few conidia ; some of these, as well as the cells of the promy- 296 U.STILAGINEAE. Fn, 162. - celia, may develop to inycelia; coalescence of coiiidia is unknown. In nutritive solutions conidia are formed in large numbers, and multiply yeast-like till nutriment fails. Ust. succisae Magn.^ frequents the anthers of Scabiosa Succisa, and forms pure white spores, easily distinguished from those of the two preceding species. The anthers appear to be thickly covered with glassy granules. The spores produce four-celled promycelia from which conidia are formed. (Britain.) Ust. tragopogonis (Pers.) (Britain). This fungus forms its spores in flowers of species of Tragopogon, and in many localities has a wide distribution. The development of the flower is retarded, so that it retains externally the appearance of a flower-bud en- closed in its bracts (Fig. 161). The dark- brown or violet spores escape through intervals between the bracts ; they are 13-1 7m long, lO-lo/x broad, with reticulate markings on their coats. They easily produce in water four or five-celled promycelia from which conidia are given off, often followed by coalescence. In nutritive solutions development is much more vigorous, secondary conidia may be produced, and coalescence always takes place. Ust. scorzonerae (Alb. et Schwein.) is at first sight very similar to Ust. fragopogonis. Its spores are found in flowers of Scorzoneixt hmnilis, Sc. -purpurea, and cultivated species, e.g. Se. hispanica ; while its mycelium hibernates in the perennial root-stocks of these. The spores are produced rapidly and in large numbers ; they germinate easily in water, forming a four-celled promycelium, and thereafter conidia which do not pair. Ust. cardui Fisch. v. Waldh. (Britain). This is the cause of a stunting of the flower-heads of Carduus acanthoidcs, C. nutans, and Silyhnm Marianum, while at the same time they liecome filled with a l)rownish- violet spore-powder. The spores ' Magnus, Heduiijia, 1875. ■ Ustilago tragopogonis. Development of spores : successive stages of development, in order of the letters, a, Sporogenous branch, just appearing on the surface of young corolla of Tragopogon pra- tensis, and beginning to form a tuft of branchlets. h and c. Formation of spores from the mycelium, d, Spore- clump with several ripe spores, the episporium of which is coloured dark-violet and thickened in a reticulate manner, (x 300). (After De Bary.) USTILAGO. 297 are about 20yU in diameter, and form in water promycelia with conidia. In nutritive solutions Brefeld found conidia produced in large numbers, and multiplying by yeast-budding. The promycelial cells grow out as septate branched twigs, from which conidia are abjointed, and after coalescing in pairs, produce germ-tubes. Ust. violacea (Pers.).^ Carnation-smut (Britain and U.S. America). In Silene, Viscaria, Saponaria, Dianthus, Stcllaria, Malachimii, Gcrastium, and Lychnis, the pollen sacs of other- wise well-developed flowers become filled with dark-violet spores, which escape and discolour the other floral parts. Pistillate flowers of LycluiiH attacked by this fungus develop stamens containing the smut-spores (p. 27). On germination in water, promycelia of three or four cells are formed, and become detached from the spores. Primary and even secondary conidia are produced, while coalescence of promycelial cells and conidia is common ; but only a few of them produce germ- tulies. In nutritive solution, according to Brefeld, everything proceeds much more vigorously; from tiny conidiophores on the promycelia numerous conidia are produced in succession, and from these other conidia are budded oft' like yeast-cells till nutriment fails, when they grow out to form hyphae. The conidia are longer than those formed in the water-cultures, and coalesce in pairs to give rise to longer and stronger germ-tubes. Ust. holostei De Bary on Holosteiini umhellatifm. The host-ovaries heconie filled with spores which germinate to four-celled promycelia from which pairinref. On Polygonum hispidum. Ust. Koordersiana Bref. On Polygonum harhatum in Java. Ust. domestica Bref. On Rumex domesticus in Norway. Ust. vinosa (IV-rk.). On fruits of Oxyria (Britain and U.S. America). The spores germinate in water or nutritive solutions, and produce a four-celled promycelium from which conidia are given off, especially in nutritive solutions ; the conidia ultimately produce germ-tubes. ^ Zooloij.-hotan, GenelL, Vienna, 1880. USTILAC40. 299 Ust, Vaillantii Tul.-' appears in the anthers and ovaries of Gagea, Scilla, Muscari, etc. The perianth of diseased llowers remains, but is somewhat enlarged. The ovaries and anthers become filled with spores ; the latter organs are, however, fully developed and may even contain pollen-grains mixed with spores. According to Brefeld, the spores germinate easily in water and in nutritive solution. A promycelium is formed which, after detach- ment from the spore, becomes three-celled and develops conidia. These sprout for some time, then produce three-celled promycelia. Ust. ornithogali (Sclini. et Kze) forms leaf-swellings on Oniithogalum and Gaijea. Ust. tulipae (HeuH.) produces swellings on the leaves of the tulij). Ust. plumbea Rostr. occnrs on leaves of Arum maculatum in Denmark. Ust. ficuum Reich. In the fruits of Ficus Carica in Asia Minor. Ust. Trabutiana Sacc. In berries of Dracaena Draco in Algeria. Ust. Vrieseana YuilL- In the Botanic Garden at Amster- dam, the roots of several species of Eucalyptus exhibited woody tumours from which proceeded outgrowths resembling " witches' brooms." These contained the mycelium of an Ustilago wliich produced spores in the cortical tissues. Ust. (.') adoxae Bref. On Ado.ra moschatelliaa in cells of tlie subterranean stem. The spores |)roduced only simple filaments without conidia. Ust. Lagerheimii Bref. On Rumea from Quito. Ust. Schweinfurthiana Thiim. On Lnperata cylindn'cu from Cairo. Ust. boutelouae-humilis Bref. On Bouteloua humilis from Quito. Ust. Ulei Henn. On Chloris. Ust. spinificis Ludw. On Spinifex hirsuta from Adelaide, Australia. Ust. Treubii Solms.^ This Javanese fungus and the galls produced by it deserve a somewhat lengthened notice on account of their general biological interest. It causes a hypertrophy on Polygoimm chinense in Java, which further exemplifies the phenomena already noticed in connection with Cacoma deformans on 'Thujoiisis (p. 30). The stems at attacked places show strong hypertrophy and great change in their anatomical structure. Solrns designates the thickenings, in common with those caused by Cacoma. ^Tulasne, Ann. d. science natiir., Ser. in., Vol. vir., 1847, with plates of Muscari. Worth G. Smith (Gardeners Chronide, xv., 1894, p. 463), gives a figure and note on occurrence of this smut in Britain. (Edit.) ^Vuillemin, Compt. rend,, 1894. •'Solms, Annal. du jardin boian. de Buifenzorore of Sphagninn. T. oryzae Pat. The fungus to which this name was given forms sclerotia in the grain of Oryza sativa (Eice) in Japan. Brefeld'^ found that dark spores are given oif from the surface of the sclerotia. These spores, on germination in nutritive solution, produced a se))tate mycelium which, in dilute solutions, gave off pear-shajsed colour- ' Kiihn, Bofaii. Zeihimj, 1876, p. 470. Cohn, Jahrburh d. Schles. Ges. f. ralcrland. Kullur, 1876. Niessl, I/i(firi:tis fiolae on Viola. Smut-pustules are present on leaf-stalks and fruit-stalks, accompanied by malformation, (v. Tubeuf phot.) the cambium remained longer active in the stem, and a secondary division of rind-parenchyma or mesophyll could be observed, along with a disappearance of intercellular spaces ; accessory vascular bundles were formed, but the secondary vessels remained incompletely developed. In short, new growth occurred, not in the earlier stages of the host's life, but in the adult. Especially noteworthy is the formation of a small-celled tissue resulting from cell-division in the rind-parenchyma and the mesophyll ; this serves as a nutritive tissue for the fungus, 1 Wakker, Pringsheims Jahrhuch, 1892. UROCYSTIS. 319 and is destroyed during spore-formation, so that the balls of spores are found in large cavities in the host-tissue. In the spore-masses the enveloping companion-cells are more transparent than the spores proper. The latter germinate^ easily in water, and produce promycelia which grow towards the air. On the extremities of these several conidia arise, and, without becoming detached, proceed at once to give off short conidio- phores with termijial conidia. As this process is repeated indefinitely, chains of conidia are formed. Fusion of conidia never occurs. U. Kmetiana Magn. Magnus- describes this as destroying and tilling with black spore-powder the ovaries of Viola tricolor (var. anrnsis). U. filipendula Fuck, occurs particularly on petioles and leaf-ribs of Spiraea FiUpendula. Brefeld found the spores germinating after a year. U. (?) italica (Sacc. et Speg.). In seed of Castanea vesca. U. purpurea Hazsl. Ovaries of Dianthus deltoides and D. prolifera in Hunuarv. U. (0 coralloides Eostr. In roots of Turritis glabra in Denmark. U. orobanches (Pr.). In roots of Orohanche. U. (0 monotropae (Fr.) In roots and stems of Monotropa in Belgium. U. Johansonii ( U. Junci. Lag.). In leaves of JinicuA filiformis in Switzerland. Tuburcinia. Spores forming lialls as in Urocystis, but all are equally capable of germination. The spore-aggregations form large or small, slightly thickened spots and crusts, which do not cause very marked deformation of the host. Germination results, as in Tillctia, in the formation of a promycelium bearing a tuft of conidia at one end. White conidia are also produced from the mycelium on the host-plant. Tuburcinia trientalis (Berk, et Br.)^ (Britain and U.S. America). Plants of Trientalis europaea attacked by this fungus are conspicuous in early summer by their swollen dark-coloured stems and their smaller lighter leaves, which fall prematurely. The conidia appear as a white mould-like coating on the lower iPrillieux, Bullet, de la Soc. hotan. de, France, 1880; and Brefeld (loc. cit.). Heft XII. -Miignus, Xaturforsch. Fr. d. Pror. Brandenhttrg, xxxi. ■'\Yoronin, Senckenberfj . naturforsch. GeselL, 1881. Plates I., II., III. 320 USTILAGINEAE. side of the leaf. The black spore-masses are formed in the rind-parenchyma, and sometimes in the pith ; they are set free by rupture of the epidermis. In autumn the symptoms are different. The plants appear normally developed, and have no coating of conidia ; dark swollen spots, however, appear on the leaves and leaf-petioles, in consequence of the massing of black spore-balls in the par- enchyma under the epidermis. The summer mycelium consists of colourless irregularly branched and slightly septate hyphae occupying the intercellular Fic). 175.— Tuburcinia trientalis. Spore- Fio. 176. — Apex of an isolated promy- mass germinating ; several promycelia have celium from Fig. 175 ; it carries a whorl of been produced and are proceeding to form branches, some of which have fused in pairs ; whorls of branches. (After Woronin.) all are developing conidia. (After Woronin.) spaces of the pith and rind-parenchyma, also the vessels. The hyphae apply themselves closely to the cell-walls, and certain short branched hyphae actually penetrate into the cells. The spore-masses are developed from delicate branched multiseptate filaments of the vegetative mycelium. They begin as two or three little cells round which a coil of hyphae is formed ; the central cells, increasing in number and size, become a ball of dark smooth-coated spores, while the enveloping coil of hyphae disappears. The spores germinate during the same autumn, frequently in the position of their formation. A proinycelium is first formed, and on its extremity a circlet of conidia arises ; there- TUBURCINIA. 321 after the promycelium becomes divided by cross-septa in its upper part, and the conidia too are frequently divided by one or two septa. The two proraycelial cells become detached, while the conidia begin to fuse together by means of out- growths near their base ; thereafter each conidium gives out a secondary conidium, into whicli the plasma-contents pass over. A similar formation of secondary conidia may take place without previous fusion of the primary conidia. The conidia fall apart, and they, as well as the upper promycelial cells thereby left isolated, grow out as hyphae. It must be these hyphae which infect the rudimentary shoots of Trientalis when they are already partially formed for next year. The resulting mycelium permeates the shoots in the following spring, and branches of it emerge through the stomata, or pass between the epidermal cells and break the cuticle, to grow up either at once as conidiophores, or to form on the surface of the leaf a web from which conidiophores arise. The pear-shaped conidia are attached by their broader side, and easily fall off, leaving the conidiophores free to produce new conidia. The conidia are capable of immediate germination, and may produce a lateral germ-tube, which grows directly upwards, and gives off secondary conidia ; or the conidia themselves grow out into hyphae, capable, as Woronin proved experimentally, of carrying out infection. Such hyphae penetrate between the walls of adjacent epidermal cells, and give rise to a mycelium which spreads in a centrifugal direction and forms the spore- masses. This same fungus has also been found on Euphrasia lutea and Paris quadrifolia. On Euphrasia, according to Winter, it causes formation of large swellings, accompanied by consider- able defoniiatiou of leaf and stem. T. primulicola (Magn.) Klihn.^ (Britain). This smut attacks flowers of Primula acaulis, P. o0einalis, P. elatior, P. farinosa. In cases described in Germany, the blooms were generally attacked in the filaments or connective of the stamens, but also in the anthers, the ovaries, pistil, stigma, and sometimes in the calyx-tube ; while the whole flower-head was more or less discoloured by the black spore-dust. The mycelium permeates ^Magnus, Botan. Verein Brandeidm^-(j , 1878. Kiilin, "die Entwickelungs- gesch. d. Priiuelbnindes," Naturfor.sch. Ge.sell. zu Halle, 1892. X 322 USTILAGINEAE. the whole host and hibernates in the root-stock. The spores are developed from the ends of hyphae in the host-tissue, and are either isolated or joined into packets. They germinate easily in water, and produce either a fine germ-tube, or a thick promycelium with four oblong conidia on its apex. The ■conidia are easily detached, and either develop to fine hyphae, or give off secondary conidia. Germination on the whole is similar to that of T. trientalis. Conidia may be also produced directly on the host-plant ; these were first described by Kiihn, who named them Paipalo'psis Irmischiae ; later, however, he succeeded in infecting plants of Primula with the conidia, and in proving their relationship to this Tuhurcinia. T. Cesatii Sorok. occurs on geraniums in Eussia. Here, according to Setcliell, the following American genera should be placed : Burillia : B. pustulata on Sagittaria. Cornuella : C. lemnae on Lemna polyrhiza. Doassansia. Spore-masses consisting of numerous spores capable of ger- mination, enclosed in a layer of sterile cells. The latter are most conspicuous in the species frequenting aquatic plants, and are filled with air, — Brefeld regards them as swimming-organs. The spore-masses lie in groups embedded in the host-plant. The species inhabit plants with an aquatic or moist habitat, and produce on them leaf-spots with black pustules. Fisch ^ investigated the life-history of Doassansia sagittariac. He found an intercellular mycelium which, inside the stomata, formed sporocarps, consisting of sclerotium-like coils of hyphae enclosing several cells which form spores. The spores on germina- tion give rise to promycelia, which produce sporidia in a manner similar to Entyloma. The sporidia easily germinate in water, and can immediately infect young leaves. The germ-tubes creep on the surface of leaves, and attaching themselves by an adhesion- disc over the wall between two adjacent epidermal cells, they penetrate this wall. The hypha, while passing ^ C. Fisch., Ber. d. devt.sch. hotan. Gcftell., 1884, p. 40.'5. Cornu, Annal. d. sci. natur. xv., 188.3. Setchell [Bolaniral Gazette, 1894) records the American species and comments on tliein. DOASSANSIA. 323 through the wall, remains thin, but on emerging into an inter- cellular space it soon thickens and branches into a mycelium. Infection results in the appearance of yellow spots, due to rapid destruction of the chlorophyll and death of cell-contents. Experiments in germination have been carried out by Setchell and Brefeld.^ Doassansia sagittariae (West.) (Britain and U.S. America). In leaves of Sagittaria. The spores, according to Brefeld, germinate in water, after hibernation. They produce unicellular promycelia with a terminal tuft of more or less spindle-shaped conidia, which at once begin to sprout and fall off. On the surface of a nutritive solution they continue to sprout yeast- like, and form close mouldy coatings. {Doassansia is the only genus of the Tilletiae in which Brefeld found yeast-like sprout- ing of conidia.) D. alismatis (Nees) (Britain and U.S. America). This inhabits leaves of Alisma Plaiitago and A. natans, producing knotty swellings. The spores are enclosed in a layer of com- panion-cells containing air, whereby the masses swim on water. On the promycelium the conidia arise from tufts of conidio- phores ; they fuse in pairs, and secondary conidia are developed from each pair or even from single conidia. D. Niesslii (de Toni) forms small spots on leaves of Bnto- mus umhdlatns. The spores are surrounded by companion-cells containing air. They germinate before leaving the spore-patch, and produce conidia, even secondary conidia, before rupture of the host-epidermis takes place. Brefeld describes the spores as germinating in water to form a very short promycelium with short thick conidia which fuse in pairs and give off larger secondary conidia from their apices. In nutritive solution conidia are developed, which give off septate filaments whence further conidia arise. Aerial conidia are ultimately developed. Magnus found that the spores of D. alismatis, D. Niesslii, and other species germinated at once on reaching maturity. Brefeld, however, found that this took place only after they had lain over winter. It may be that here, as with some higher plants {e.g. Finns Cemhra), there is an immediate capability of germination, but also a deferred, the latter requiring iSetchell, Annals of Botany, vi., 1892. Brefeld, Schivunelplhe, Heft xii., 32^ USTILAGINEAE. to be preceded by a considerable resting-period, during which germination will not take place. D. Martianoffiana (Thiim.). In leaves of Potamogeton natans and P. grumineus. D. occulta (Hotfni.). In fruits of species of Potamogeton. D. intermedia (Setcli.). An American species found on leaves of Sagittai-ia varia h il is . D. comari (Berk.). In leaves of Gomaruni pcthistre in Britain. D. limosellae (Kunze.). In flowers of Limosella aquatica. D. hottoniae (Rostr.). In leaves of Hottonia palustris in Denmark. Thecaphora. Spores, large, spherical, and inseparably united into packets of several spores. Germination results in the formation of a Fig. 117.— Thecapkoni hmilaa. Pluricellu- lar spore, with two cells (spores) germinatlug. (After Woronin.) '0 Fig. its. — Sorosporium saponariae (var. Lychnidis dioicae.) Mature spore-mass, and germinating. (After Woronin.) promycelium from the apex of which a single conidium is produced. Thecaphora lathyri Klihn. Spore-balls formed in the seeds of Lathyrus ^9?'ai!e7ms, and escaping as a brown powder on dehiscence of the pods. The spore^ germinate in water with formation of a promycelium bearing a single apical conidium, which produces a hypha, but never secondary conidia. In nutritive solutions the spores produce a mycelium from which conidia are continuously given off. Th. hyalina Fingerh. (Britain). This occurs in fruits of species of Convolvulus. Woronin describes the spores as having germ-pores through which a septate germ-tube is emitted ; the individual cells of the germ-tubes develop into hyphae, without formation of coiiidia. Th. affinis Sclmeid. In fruits of Astragalus glycyphyllus (U.S. America). Th. Trailii Cooke. In flowers of Cardmis heterophylhis in Scotland. THECAPHORA. 325 Th. Westendorpii Fiscli. In Lolmm perenne in Belgium. Th. pimpinellae Juel. In fruits of Pimpinella Saxifragct, in Sweden. Th. aurantiaca Fingli. In leaves of Urtica dioica. Th. pallescens Fingli. In leaves of Fragaria collina. Sorosporium. Spore-formation takes place in a mass of twisted gelatinous hyphae. Spores at first embedded in a gelatinous investment and united into packets, but later becoming separate. Promy- celiuni filiform and septate. Sorosporium saponariae Eud. This causes deformation of fiowers of Diaiitlius deltuidcs, Saponaria officinalis, Silene inflata, and S. velutina, Stcllaria Holosteum, Cerastium arvense, Lychnis dioica, and Dianthus prolifcr. S. dianthi Eabh, on Dianthus prolifer, is probably identical with the preceding species. We append here as doubtful Ustilagineae, the genera Grcqihiola Schinzia {Entorrhiza), Tidierculina, and Schroetcria. Graphiola. The sporocarps of this genus are formed on the surface of plant-organs containing mycelium ; they are little spherical structures enclosed in a peridium, and contain filamentous septate hyphae. The hyphae may be sterile or fertile ; the spores are produced on lateral cells of the fertile hyphae. From the germinating spores, either a thread-like mycelium or spindle-shaped conidia arise. Graphiola phoenicis Pait.^ (Britain.) This fungus is a parasite on leaves of palms {e.g. Phoenix dactylifcra and Chamcrops humilis) in the open in Italy and other Mediter- ranean countries, in hot-houses elsewhere. The sporocarps make their appearance as little black protuberances on both sides of the leaf. The mycelium forms a close hyphal tissue, which encloses and kills parenchymatous cells, displaces the bundles of sclerenchyma, and ruptures epidermis and hypoderm. De- formation is, however, localized to these spots. ' Ed. Fischer, " Beitrag z. Kenntniss d. Gattung Graphiola," Botan. Zdtiing, 1883. 326 USTILAGINEAE. The sporocarps consist of a two-layered peridium, a sporogenous layer, and tufts of sterile hyphae. The outer layer of the peridium forms the outer layer of the black protuberances on the leaves ; the inner layer is delicate. The sporogenous hyphae originate from the centre of the underlying hyphal tissue, and form a palisade-like layer in the bottom of the sporocarp cavity, the remaining space being filled with spores and tufts of barren hyphae. These latter hyphae rise amongst the sporogenous ones, and project as a fine brush-like tuft out of the ruptured peridium. The sporogenous hyphae grow vertically upwards, and become septate, forming chains of loosely united, roundish, hyaline cells or joints. The terminal joints give off several spherical cells laterally, and die away, leaving the cells loose in the sporocarp cavity. From division of the spherical cells yellow spores result, and, on rupture of the peridium, are carried out on the tufts of sterile hyphae to be scattered by wind. The spores germinate in water, and produce either a promycelium or conidia. Gr. congesta Berk, et Eav. occurs on leaves of Cliamcrops Palmctta. Schinzia (Entorrhiza).^ Spores produced on the ends of lateral branches of a mycelium in the cortical cells of the root of the host-plant. Germina- tion results in production of a simple or branched sporophore (promycelium), from which kidney-shaped conidia (sporidia) are produced. Schinzia cypericola ]\Iagn. This causes deformation of the roots of Ci/ptrus favescem (Fig. 179). Sch. Aschersoniana Magu. causes swellings on the roots of Jimcus hufonius [Britain]. Sch. Casparyana Magn. In roots of Juncvs Tenageia. Sch. digitata Lagerli. In roots of Juncus articulahis. Sch. (Naegelia) cellulicola Naeg. In roots of Iris in Switzerland. Sch. (Entorrhiza) solani Faut.- [This is given as the cause of a disease on potato. The plants droop and ultimately rot at the neck, the leaves become yellow, and neither Howers nor tubers are produced.] (Edit.) ^P. Magnus, at Botan. Vereiu d. Prov. Brandenburg, 1878; " Ueber einige Arten d. Gattung Schinzia;' Brr. d. ibutsrh. hofaii. Gts., 1888, p. 100; C. Weber, Botav. Zeitimij, 1884. '^ Fautrey, Bevite mycoloij., 1896, p. 11. TUBERCULINA. 32T Tuberculina. Mycelium parasitic on hyphae and spore-patches of Uredinme. Short rod-like hyphae spring from the spore-patches, and give off' from their apices, globose conidia, which on germination produce branched promycelia bearing sickle-shaped conidia. Fio. 179. — Schinzia cyptricola on Cyperus flavescens. Several roots show palmately- divided swellings. Isolated spore. (After Magnus.) Tuberculina persicina Ditm. The lilac-coloured spores are found on aecidia of I'eridcnntum 2nni and other aecidial forms, also on some species of Cacoma} (Britain and U.S. America.) ^ Plowright (British Ustilagineae) gives also Aec. afiperi/olii, Aec. tumlaninin and Roe-ftelia lacerata as hosts. 328 USTILAGINEAE. T. maxima liostr. Occurs on rust-patches on Weymouth pine. It has larger spores than the preceding species. Schroeteria.^ Spores joined in pairs, rarely in threes, with their broad faces together. They are developed from single joints of a septate non-gelatinous mycelium, particularly from short curled lateral hyphae. Spherical conidia are produced, like those of PeniciUinm, by intercalary growth in chains from the end of a •conidiophore which is generally unbranched. Schroeteria Delastrina (Tul.) occurs in seeds of Veronica arvend^, V. hedcrifolia, V. triplitjUa, and V. praccox. The spores terminate in water, and produce conidia incapable of further de- velopment, even when transferred to a nutritive solution. In such, however, spore-germination is more vigorous, and an abundant mycelium results, but it seems to be unable to produce conidia. Sch. Decaisneana (Boud.). In seeds of Veroiiica hederifolia at Paris. UREDINEAE. The Uredineae or liust-fungi possess several forms of spores, one of which, the teleutospore, is rarely, if ever, absent from the life-cycle of any species. The teleutospores consist of one, two, or more cells enclosed in a thick coat of dark colour, and thereby well adapted to carry the fungus over winter. "When germination occurs, each cell of a teleutospore gives off a germ- tube through a pore or thinner place in its wall, and from this a promycelium^ is formed, consisting as a rule of four cells. Each teleutospore originates from a sporophore of its own, and in the course of development two nuclei, originally present in each cell of the young teleutospore, fuse together. When germination takes place, and the promycelium is formed, the single cell-nucleus, derived as above, divides into two, then into four, so that a nucleus is produced for each of the cells of the promycelium. From the promycelium four sterigmata are given off, and each produces a single sporidium.- These ' Brefeld regards the species as forms of higher fungi, not as Ustilagineae (Heft XII., p. 204). - Brefeld considers that the promycelium and sporidium are respectively a basidium and a basidiospore. UREDINEAE. 329 sporidia on germination give infecting mycelial hypliae. In the case of Coleosijoritdn, the promycelium is formed inside the teleutospore in a manner similar to the Protobasidiomycetes. Besides teleutospores, there occur uredospores. These are given off from patches or sori throughout the summer till autumn, when they are followed by teleutospores on the same sori. The uredospores somewhat resemble the teleutospores, but generally consist of one cell only with a thinner coat of lighter colour ; they either germinate at once without a resting period, and give rise to a germ-tube capable of direct infection of new hosts ; or less frequently they are resting-spores for a time. A third form of spore occurring in the life-history of the Uredineae is the aecidiospore, produced in a special structure, the aecidium. The aecidium is developed inside the leaves or other organs of the host-plant, and when mature ruptures the overlying epidermis ; it has as a basis a firm liyphal tissue, the upper surface of which becomes a disc of short erect sporo- phores. From each sporophore there is formed by intercalary growth a chain of cells consisting alternately of spores and smaller intermediate cells, which do not become spores. The youngest cells in an aecidium are those next the sporophore- disc, and they are forced outwards by intercalation of younger cells between them and the disc. The cells so produced become alternately intermediate cells and spores ; the former increase for a time, then decrease and disappear, the spores liowever continue to increase in size as the chain grows forward and to take on the characters of the mature aecidiospore till they are finally shed from the aecidium. The production and distribution of aecidiospores may thus go on continuously for a considerable time. The sporophores at the periphery of the disc do not however produce spores ; chains of cells are also produced from them by intercalary growth, but the cells are of equal size, and remain closely connected with their neighbours, so as to form a membranous covering over the spore-sorus, this is the so-called peridium, on rupture of which the aecidio- spores escape. In many Uredineae the peridium is suppressed (Cncoma) ; in others {Phrafjmidium) it is replaced by other structures, the paraphyses. The spores of the genus Endophyllnm are produced in series in aecidia enclosed by a peridium, but in 330 UREDINEAE. geniiiuatiou they behave more like typical teleutospores than aecidiospores. Before the relationship of these various forms of spores was known, Aecidium and Caeoma were regarded as independent groups, and named as such ; even yet many isolated forms of uredosporcs, teleutospores, and aecidiospores are known, the relationships of which are quite obscure. The aecidia are always preceded or accompanied by a further form of spore produced in a special structure of its own. These spores have hitherto been called spermatia, and their sporocarps spermogonia, on the assumption that they were male organs. Now, however, many of them are known to be capable of germination in artificial nutritive solutions, hence they are more probably a form of asexual bud, and better named conidia, their sporocarps pycnidia. The pycnidia are tlask-shaped structures sunk in the tissue of the host, with a pore or mouth emerging through the host-epidermis ; they generally occur in leaves, and occupy the upper epidermis, the aecidia occurring on the lower. From the mouth of the pycnidium there frequently emerges a tuft of fine filaments, outgrowths from the inner wall of the flask. The pycnidia possess a lively colour and flowery odour, hence it has been suggested that the conidia may be distributed by insects; but they do not appear to be able to germinate in the open, and infection- experiments with them have never as yet succeeded. On this account they are regarded as degenerate structures.^ The various forms of spores are also distinguishable by the manner in which they bring about infection. Teleutospores on germination produce sporidia, which pierce the membranes of the prospective host at a spot where two adjoining cells are in contact, and thus make their way into the intercellular spaces. Uredospores and aecidiospores, however, first seek a stoma and enter the intercellular spaces of the host through it. The following different forms of Uredineae exist : (1) Those which possess teleutospores alone, e.g. Chrysomyxa alietis ; (2) those with teleutospores and uredospores, e.g. Fuecinia 2^'^'uni sinnosac ; (3) those with all the forms of spores, e.g. Puccinia graminis ; (4) those without uredospores, e.g. Gymnosporangium. 'Rathay, " Untersuchungen iiber die Spermogonien d. Rostpilze," Diitksrhri/t d. Wiener Akad. d. Wissennch., 1883. UREDINEAE. 331 Tlie difierent forms of spore may be found on one and the same host-plant (autoecious Uredineae), or the aecidiospores and pycnidial conidia may frequent a different host from the uredo and teleutospore-forms (heteroecious Uredineae).^ A mycelium may be produced from the germinating aecidio- spores, uredospores, or sporidia. It spreads throughout the intercellular spaces of attacked organs and causes thickening, distortion of the tissues of its host, or the formation of " witches' brooms." Xutriment is frequently obtained by means of cone- shaped or button-like haustoria in the interior of host-cells. Hibernation of rust-fungus is most commonly attained through the teleutospores, the thick coats of which make them peculiarly suited to pass through a lengthened resting-period. Some forms, however, hibernate by uredospores, by aecidiospores, or by the mycelium remaining on or in living perennating stems, twigs, or underground rootstocks of their host. Aecidiospores on germination produce, as a rule, a mycelium which gives rise to uredo- or teleutospores, rarely to aecidiospores (e.f/. Puccinia scnecionis and Uromyccs crri)} Uredospores on germination, produce a mycelium from which uredospores are first given off, then teleutospores. The sporidia of teleutospores give rise to a mycelium which frequently produces pycnidia and aecidia. In rare cases, the sporidia of species, which normally form aecidia, are said to develop a uredo-mycelium {cf). Puce, yraminis according to Plowright). The Uredineae are for the most part strict parasites, and exhibit marked adaptation to their respective host-plants. Several of the polyxenous members frequenting several species of host- plant have been found to vary according to their habitat, so that one and tlie same species assumes a slightly different form on each ' The phenomenon of heteroecisni was till quite recently known only amongst the Uredineae. Woronin and Nawaschin ha\e, however, recently pointetl out that it exists in Sr/erotinia Itdi, one of the Ascomycetes (p. 277). The conidia of this species are produced only on Varcinium uli(iiHo<lack- rust or summer-rust.^ Uredospores and teleutospores occur on various species of Gramineae, the pycnidia and aecidia on species of Perbci'is or Mahonia. ' Clinton in Report of Agricultural Station of University of Illinois, 1893. -A valuable monograph on the rusts of cereals has been published by Eriksson and Henning (Die Getreideroste, Stockholm, 1896). 342 UREDINEAE. The two-celled which form lilack 'J teleutospores arise from cushions or sori lines on the haulms and leaves of grasses ; they hibernate on the decayed remains and germinate in spring. Each cell of a germinating teleutospore gives off a four-celled basidium (promy- celium), with four short sterigmata from each of which a basidiospore (sporidium) is abjointed (Fig. 182). The sporidia are carried off the grass-host and germinate at once if they alight on leaves or Howers of Bcrberis or Mahonia (Fig. 183). (Tcrm- tubes are formed which penetrate the outer walls of the host into the epidermal cells. The mycelium which results is a branched septate one, and spreads through the inter- cellular spaces of the leaf. About eight days after infection, little yellow spots make their appearance on the upper surface of the leaf. Embedded in the spots will be found the pycnidia (spermogonia), spherical flask-shaped enclosures developed on a web of hyphae, and with their inner walls clad with short rod-shaped conidiophores (sterig- mata), each of which gives off a tiny coni- dium (spermatium) (Fig. 184). A tuft of periphyses arising from the upper part of the pycnidium wall carries the conidia out of the pycnidia in drops of a honey-like fluid emitting a characteristic odour. In regard to the function of these conidia nothing definite is known. The next stage begins with the appear- ance of yellow spots on the lower epidermis of leaves. These indicate the presence of a mycelium from which the aecidia take their origin. The aecidia are at first en- closed in a one-layered peridium under the leaf-epidermis, till by their increasing size they rupture both coverings, and project above the surface as cups containing spores (Fig. 184). The aecidiospores originate in a layer of Fia. WL — Puccinki firaiu- inis. Genniniitliig tcloito- spore. The promycelium has formed three sterigmata, from the ends of which sporidia are in . process of abjunctlon. (After Tuhisne.) pucciNiA. 343- hyphae forming the bottom of the uecidium-cup. These hyphae give rise to numerous short sporophores, from each of which a single long chain of spores is abjointed in basipetal succession, the spores being at first separated by temporary intermediate cells. The sporophores round the margin of each aecidium do not, however, give off spores ; they also produce chains of cells basipetally, but these grow larger and, without the inter- vention of intermediate cells, remain sterile and become joined Fig. 183. — Puccinia r/ramiiiis (Aecidium herberidis) on Berheris communis. The lowest leaf and two others are seen on the upper surface, and show red spots with light margins, in which the pycnidia are embedded. The other leaves show the under surface with patches of aecidiu. (v. Tubeuf del.) to their neighbours to form ilie peridium. Diseased portions of leaves become considerably thickened. The cells of the single layer of palisade parenchyma are abnormally elongated, and the intercellular spaces of the spongy parenchyma, instead of being large, are small and filled with mycelium. The aecidio- spores escape in July to germinate on Gramineae. The germ- tube enters the host by the stomata only, and develops into an intercellular mycelium ; this in about eight days produces uredospores from cushions or sori which form lines, and break 34-t UKEDINKAE. tlirougli the e})iderniis. The yellow uredospores are abjointed singly from long sporophores ; they are unicellular and ovoid, with a thin granular coat beset with germ-pores (Fig. 184). The uredo- spores are easily conveyed to other grass-plants and germinate at once, their germ-tubes entering by a stoma and developing into a mycelium, which can produce a new crop of uredospores in a Fig. 18i.—Puccinia graminis. A, Portion of transvei-se section of leaf of Bcrberis vulgaris, with a young aecidinm under the epidermis, v.. I. Section through an aecidium-bearing spot of a Barberry leaf. At x the normal structure and thickness of the leaf is shown, the portion u to p is abnormally thickened ; It to o, upper siirfaco of the leaf ; sp, pyenidia ; a, aecidia , sectiu a peridinui (■\|»i-(-l in -u: ^11. Matmv t^l. i, . 1 in. TclcUlos'l..,,. . '.', ;,ll at its apex, the urcdcsjH (After l)e Bary, from Sach's Lehrbuxh.) -•idium marked p alone (without «) shows ly. . mg through the epidermis, e, from the . t eleutospores. x 190. s, ii,i\ The teleutospore has a germ-poro ur gcnn-pores at their equator. x 390. few days. The uredospores are summer-spores, and spread the fungus during the vegetative period of the host-plant ; they may, however, hibernate. The teleutospores are more suited for hibernation ; they are produced in autumn from dark brown linear sori, distinguished from these of the uredospores by their darker colour and greater length. The teleutospores are two-celled and obovoid with smooth thick walls (Fig. 184); they arc, like pucciNiA, 345 the uredospores, developed from long sporophores, and are in this way distinguished from those of Puce, ruhigo-vcra, which are very short. The teleutospores germinate in spring after hibernation, each cell giving off' a single germ-tube. Ijotli uredospores and teleutospores are injurious to our cereals, — wheat, oats, and rye. They may also be found on the following species of grasses: Anthoxanthum, Aloijccnrus Phlcum, Aff/vstis, Aira, Avena, Brizn, Arrhenathcrum, Poa, Dadylis, Festuca, Bromus, Triticum, Secede, Elymus, Hordevm, Lolium, Agropyrum, Androjjoyon, Bryzopyrum, etc. The disease may ruin a whole harvest of grain, and render the straw disagreeable, if not dangerous, for stable use (see also p. 84). Kemoval of barberry bushes is said to reduce the rust, although many believe that the barberry is not necessary for the existence of the fungus.^ Plowright, for example, found that sporidia from teleutospores infected wheat-seedlings directly, without intervention of the aecidiospore stage. It is also possible that the mycelium hibernates like that of Puce, ruhigo-verct, in some wild grass, to grow again and produce uredospores in spring. No very effective measures against this fungus are known. Early sowing has been suggested; and certain varieties of grain, known to be less liable to attack than others, might be used. Eriksson and Henning,- from the results of their infection- experiments, have provisionally distinguished the following varieties of P. gmminis : A. Definite — (a) distinct varieties : 1. Var. seccdis on Secede cercale, Hordrvm vidgarr, Triticum repens, and Elymus arenarius. 2. \-A\\ iirencic on Avena sativa, Milium effusum, Alopccv.ru s prafcnsis, Dcictylis glomeratct (and Arenci elatior). 3. Var. (lirae on Aira cacspitosa. (/3) somewhat uncertain varieties : 4. Var. agrostis on Agrostvi canina, and A. sfolonifera. 5. Var. poae on Poa compresm (and P. pratensis). />'. Xot sharply defined : 6. Var. friliri on Triticum vulgarc. ' An interesting discussion of this subject is given by Wor. O, Smith (Diseases of Crops, Chap. xxv.). (Edit.) -Eriksson and Henning, " Untersuchiniiren ub. d. (ietreideroste,'' Zeitsrh. f. Pflanzmkrankhitui, 1894. 346 UREDINEAE. Puccinia coronata ('(nda. (Ihitain and U.S. America.) Eriks.son, iVoin hi.s own expeiiuionts and those of Klebahn, distinguishes llie I'ollowini; specialized varieties: Ser. I. Aecidia on lihamnus cathartica, Rh. clacoidcs, Bli. yrandifolia, Rh. alnifolia {Puccinia coronifcra Kleb.). 1 . Var. avcnae on Avcna sativa. 2. ^'ar. alopccuri on AlojKcurus ^;r«. Var. hromi on Brvmus arvensis (and Br. hrizacformis). 4. Xax. arjropi/ri on Triticum repcTis. P. rubigo-vera (D.C.) (P. straminis Fuck., F. striaeformis West.). (Britain and U.S. America.) This, in its uredo- and teleuto- spore stages, frequents various grasses, while the aecidia occur on Boragineae. A variety on species of Hordmm has been designated P. simjylcx. The teleutospore-patches are enveloped in numerous brown paraphyses ; the teleutospores have very short stalks. The anatomical changes produced in leaves beset with aecidia have been stated by Wakker as follows : The swelling of the leaf-petioles is due to enlargement of their cells ; the large intercellular spaces of the spongy parenchyma are no longer ^ Fentzling, I naurniral Dissertation. Freiburg, 1S92. -Found along with tlie Aecidium at Montrose (.Scotland) by Prof. .1. W. H. Trail. (Edit.) 348 UIIEDINEAE. ])reseiit : ihe jmlisailL' layiT is (IouI)I(hI, and rupture of the epidermis takes place ; chlorophyll-forniatiou is suppressed, the cell-sap becomes yellow, and starch tends to accumulate. P. dispcrsa may cause serious damage to wheat and rye ; F. rnhifjo-vcra, also on barley and oats. The spore-patches are found on stalks and leaf-sheaths more than on the lamina. The mycelium may hibernate in grasses, so that the fungus is not dependent on the aecidial stage ; for this reason the disease is not easily combated. P. glumarum Eriks. et Henn. Golden-rust. This species, hilherlu generally included under P. rubifjo-vrra (D. C.) has been separated by Eriksson and Henning.^ Experimental infection on Boragineae gave negative results. Eriksson distinguishes the following specialized varieties of this species : A. Definite (and undoubtedly distinct). 1. Var. trificl on Triticum vulgare. '1. \'ar. hon/ei on Hordenm vulgare (somewhat uncertain), o. Var. (iijmi on Elymus arenarius. 4. Var. a(jro}iyri on Triticum repens. B. Xot sharply defined : 5. Var. stecalis on Sccalc errca/r. The uredospore-sori are lemon-yellow in colour, and form lines on the leaf-blade which may run together and reach a length of 10 mm. The teleutospore-sori form long, fine, brown or black lines : the sori are divided into numerous chambers, each enclosed in a circle of curved brown paraphyses. The spores germinate in the autumn of the same year. The pro- mycelium is yellow till tlie spores are abjointed : in this way it is distinguished iVom P. ilispci'sa. P. poarum Xiels. (Britain). Uredo- and teleutospcjres on /''/". According to Nielson, the aecidia occur on Tussilago, Pda.sift's, and Adcnostylrs. Fentzling {lor. fit.) has described certain anatomical changes which accompany deformations due to the aecidia. P. phlei-pratensis Kriks. et Heun. Tliis lia.s a liil)tniiatiii<;- iiiycelium wliifli produces uredospores I'ontinuoiisly on Phleum and inoliaUIy also on Factum. Aecidia liave not as yet been observed. ' Kiikssoii and Heniiiiig \loc. ri/.). pucciNiA. 349 P. agrostidis Plowr.' Teleutospoi'es on Agrostis vulgaris ; aecidium = Aec. (((juilcgiae Pers. (Britain and U.S. America). P. festucae Plowr.' Uredo- and teleutospores on FcMura ovina and /"'. chiriuscula ; -AvcuVunw = Aec. periclymeni Schuni. (Britain). P. phragmitis (Scliuni.). Uredo- and teleutospores on Pkragmifes. Aecidium = J^'f. ruhdlum on Rinm'.t crispus and other species of Rumex, also on Rheum. (Britain and U.S. America.) P. Trailii Plowr. Ui-edo- and teleutospores on Phragmites communis. Aecidium on Rume.r Acetosa. (Britain.) P. Magnusiana Korn. Uredo- and teleutospores on J'limgmites communis. Aecidium on Ranunculus repens. (Britain.) -' P. moliniae Tul. Uredo- and teleutospores on Moliniacoerulea. Aecidium (according to Rostrup's out-of-door experiments), on Orchis repens, 0. mascula ; probably also on other Orchideae. (Britain.) P. nemoralis Juel. Uredo- and teleutospores on Molinia coerulea ; aecidium {Aec. melampi/ri Kze. et Schm.) on Melampi/rum pratense. P. australis Kbrn. Uredo- and teleutospores on Molinia in Tyrol ; aecidium {Aec. erectum, according to Pazschke) on Sedum refle.re, S. acre, etc. P. perplexans Plowr. Uredo- and teleutospores on Alopecurus pratensis ; aecidium on Ranunculus a<-ris. (Britain.) P. persistens Plowr. On Triticum repens. Aecidium =Jt'r. thalictri (Britain). P. sesleriae Eeidi. On Sesleria coerulea. Aecidium on Rhamnus sa.vatilis. P. Winteriana ^Nlagn.'' (/'. .sp.«///.y, Selui.). Uredo- and teleutospores on Phalaris arumlincicea. Aecidium on Allium ursinum {Aec. alliatum Rbli.). P. sessilis Schn. (including P. digraphiclis Soppitt and P. paridis Plowr.) (Britain.) Uredo- and teleutospores on Phalaris arundinacea. Aecidium, according to Soppitt,** on Convallaria majalis, also on Majanthemum, Paris, Polygonatum, Lilium canadense and Streptopus Smilacina. Klebahn's experi- ments confirm the relationship of the aecidium on Majanthemum, Convallaria, Polygonatum, and Paris. P. phalaridis Plowr. On Phalaris arundinacea. Aecidium {Aec. ari) on Arum italiorm and A. maculatum. (Britain.) P. agropyri Ell. et. Ev. On Agropyrum. Aecidium = Jec. clematidis D. C. on Clematis Vitalba and C. recta, etc., in Europe and America. P. caricis (Schum.) (BritaiQ and U.S. America). Uredospores and teleuto.si)ores on species of Carex. Aecidia, according to Magnus, on Urtica (Fig. 185). The same author also believes that the uredo-stage can hibernate. iPIowright, Grevillea, xxi., 1893, p. 109. -Klebahn (Ze(<.>Y/t. /. Pflanzenkrankheittn, 1892) confirms Plowright's observa- tions on this. ^Magnus, Htdirlijla, 1894. ■•Soppitt, Journal of Botany, 1890. 350 UREDINEAE. Stems, leaf-stalks, and leaf-nervature often undergo one-sided tlnckening and curvature as a result of formation of aecidia. Wakker thus summarizes his observations on the anatomical changes in these malformed parts of Urtica : tliere is an en- largement of cells and an increase in the number of large inter- cellular spaces ; no formation of collenchyma, interfascicular cambium, and chlorophyll ; a diminished formation of calcium oxalate ; an orange coloration of the cell-sap ; and a distension or rupture of the epidermis. Fio. ISa.— /"i/.ccmja co/ricis on Stinging Xettle. The aecidial cushions have caused sweUing and distortion of stems and leaf-stalks, also swollen outgrowths on the leaves, (v. Tubeuf phot.) Klebahn and Magnus believe that there is a Fuccinia on Carex acuta and G. Goodenoughii related to an Accidium on Rihes Grossidaria, B. rubrum, and B. aure^cm ; also a Fi/ccmia on Garex riparia with an Aecidium on Hibcs nigrum. (_)n this account Klebahn ^ distinguishes Puce, caricis i., ii., and in., agreeing respectively with P. Pringsheimiana Kleb., P. caricis (Sclmiu.), and P. Magiiusii Kleb. P. Schoeleriana Plowr. et Magn.^ (lUitain). Uredo- and teleutospores on Gctrcx arenaria ; aecidia on Scnccio Jacohaea. 'KleV)ahn, ZeMxrJirift f. Pflanzenkrankhdten, 1892, 1894, and 1895. - Iledingia, 188(5. PUCCINIA. 351 P. sylvatica Schroet. (Britain). Uredo- and teleutospores on C(iri\r: aeeidia on some Compositae. Schioeter^ regards an Accidium on Taraxacum officinale and Senccio nemorensis as lelated to the teleutospores on Carcx brizoidcs and C. praccox. Klebahn - reared aeeidia on Taraxacum after infection with teleutospores from Carex arenaria ; E. Fischer obtained aeeidia only on Tara^iacum officinale. Dietel ^ regards Accidium Bardanac on Arctium Lappa as related to this species. Attacked leaves of Taraxacum are frequently much deformed, stunted, and twisted. Those of T. officincdc have orange-red warts on the lower surface, and there Fentzling {loc. cit.) found both spongy and palisade parenchyma increased and more or less deformed, the cells being elongated and enclo.sed in hyphae. P. leucanthemi Pass. According to E. Fisclier, the uredo- and teleuto- spores are found on Carex montana; the aeeidia {Aec. leucanthemi) on Chi-i/saathem nm Leucanthemum. P. tenuistipes Eostr. Uredo- and teleutospores on Carex muricata ; aeeidia on Ventaurea. P. arenariicola Plowr. et Magn. On Carex arenaria ; aeeidia = J ec. rent- aureae on ('. nigra. (Britain.) Ed. Fischer found that the species of Puccinia on Carex inontana (one with its aeeidia on Centaiirea Scabiosa, the other on Centaurea montana), were specifically different. P. limosae Magn. Uredo- and teleutospores on Carex limosa ; aeeidia on Li/siirii(thia. thi/rsifolia and L. ralgaris.* P. extensicola Plow. (Britain.) Uredo- and teleutospores on Carex extenm ; aeeidia on Aster Tripob'um. P. dioicae Magn. (Britain and U.S. America). Uredo- and teleutospores on Carex dioica and ('. Davalliana ; aeeidia on 6Vr5ZM»i (according to Kostrup and Schroeter). P. firma Dietel. Teleutospores on Carex Jirma; aeeidia on Bellidiastrurn. P. vulpinae Schroet. Uredo- and teleutospores on Carex vulpina ; aeeidia on Chrysantheraum TanacetumJ' P. paludosa Plowr. (Britain). Uredo- and teleutospores on Cai'ex vulgaris, .tc. Plowright gives Aecidium pedicularis as the aecidial form. The attacked jjlants of Pedicidaris are often considerably deformed. P. uliginosa Juel.*' Uredo- and teleutospores on Carex vulgaris ; ' Pihe Schlexien-'^. -Klebahn, Zeitxchi-i/t f. PjJanzenkrankheiten, u., 189-2. ■' Dietel, Oesterreich. hotan. Zeitung, 1889. ^Magnus, Tarjhl. d. Naturforsch. Vtreins in Milucken, 1877. •' Schroeter, Pi/ze Sch/e-siens. ^ Juel, Mycoloij. Beit. VeteuscajM-Akad. ForhamU, 1894. 35: UREDINEAE. aecidia {Aec. parnassiae Schleclit.) oi jycnidia are unknown Parnassid palustris. Sperniogonial pycniclia are unknown. P. scirpi D. C. (Britain). Uredo- and teleutospoi-es on Scirpus; aecidia, according to Chodat, = .1 ea nymphaeoides on Nymphaea, JV^iphar, and JJvi- accor nInU'OHh: l-'iii. \h>i. — l'iixfiiiM soMAtolins on Cirsiain urvensc. Tlie plants are abnormally elongated ; the leaves have remained smaller and simpler, and are thickly beset on the lower side with patches of chocolate-brovrn iiredospores. (v. Tubeuf phot.) P. eriophori Tlilini. Uredo- and teleutospores on Eriophorum latifolmm in Siberia and Denmark ; Rostrup gives as the aecidial form Aec. cinerariae Kostr. P. obscura Schroet. Uredo- and teleutospores on Luzula ; aecidia on Ikllis perennis (Plowriglit). (Britain and U.S. America.) P. septentrionalis Juel. Uredo- and teleuto.spores on Polygonum viri- parum; aecidia (.lee. Sommerfeltii) on Thalictrum alpimim in Scandinavia, pucciNiA. 353 Iceland, Greenland, and Switzerland. Juel states tliat this is the only heteroecious Puccinia whose uredo- and teleutospores inhabit a dicotyle- donous plant. {2) Accidia are absent ; pycnidia, urcdospores, and teleutospores developed on the same plant. {Brachypuccinia, Schroet.) : Puccinia suaveolens (Pers.) (Britain and U.S. America). One tuiiii on Cirsunii arvense, and a second on Centaurea Ci/ani/s. Pycnidia and uredospores appear first, then teleutospores develop amongst the later-formed uredospores. The shoots and leaves of attacked plants are permeated with mycelium and rendered conspicuous by their elongated shape, lighter colour, and smaller, less lobed, softer leaves (Fig. 186). Diseased plants bear no flowers. Wakker on investigating the diseased stems found : non-development of those sclerenchyma- sheaths of the primary tissues situated towards the interior of the stem, whereas those towards the outer side show secondary thickening ; irregularities occur in the interfascicular cambium, so that the phloem becomes abnormally developed and propor- tionately more extensive than the wood, it may also be divided by a band of sclerenchyma. P. hieracii (Schuni.) (Britain and U.S. America). On numerous Com- positae, e.g. Carlina, Cirsium, CardtmSy Centaurea, Leontodon, Scorzonera, Crepis, Hieracium, Cichorium, etc. Plowright distinguishes tw(j allied species on Compositae, \'v/.. P. centaureue, Mart, on Centaurea nigra, and P. tarcLvacI Plowr. P. bullata (Pers.) (Britain and U.S. America). On Umbelliferae, e.g. Apium, Petroselinum, yEthiisa, Selinum, Conium, Anetkxm, etc. On culti- vated species (e.g. Parsley, Dill, Celery, etc.) it may prove troublesome.' P. oreoselini (Strauss). On Peucedanum and Heseli. (U.S. America.) P. helvetica Schroet. On Asperula taurina. (3) Uredospores and teleutospores alone known. The related pijenidia and aecidia have either not as yet been traced, or do not e.ii/mi Lagerli.). On Elymus arenariv.s and E. mollis. P. Baryi (Berk, et Br.). On Brachypodium in Europe and Britain, Bambiisa Tlwuarsil in India, Anch-opogon, etc., in America. P. longissima Scliroet. On Koeleria cristata in Germany ; K. Berythria ill Eoy])t. Fig. '[i,~.—F,'n una sorghi {Puce, mai/chs). Portion of Maize-leaf showing spore- patches, (v. Tubeuf. del.) Fig. 1S9. — Puccinia sorghi. Three teleutospores and two uredospores. One of the latter exhibits the tiny point-like projections of the membrane, (v. Tubeuf del.) Fig. ISS.— Puccinia sorghi. Section of leaf of Zea Mais filled with mycelium. The epidermis is ruptured by a spore-sorus. At one end there are still the remains of a urcdospore-sorus and a few uredospores. (v. Tubeuf. del.) P. paliformis Fuck. On Koeleria eristata. (Britain.) P. anthoxanthi Fuck. On Anthoxanthum odoratum. (Britain.) P. gibberosa Lagerli. On Festiica sylvatica. P. angustata Peck. On Scirpus and Eriophorum. (U.S. America.) P. junci (Straus.s). On Jtineus. (U.S. America.) P. oblongata (Lk.). On Lnznla. (Britain.) pucciNiA. 355 P microsora Kuril. On Carex vesicaria. P. caricicola Fiick. On Carex supina. P. allii (D. C.). Onion-rust. (U.S. America.) P. iridis (I). C). On Iris. (Britain.) P. veratri Niessl. On Veratnim album and T'. viride. (U.S. America.) Puccinia pruni Pers. Plum or Prune Eust. [This is a common species in both Europe and the United States ; it attacks almost every kind of cultivated drupaceous fruit, includ- ing prune, plum, peach, nectarine, apricot, cherry, and almond. The uredospores are brown, the teleutospores darker, and both are as a rule found only on the under surface of the leaf (Fig. 82). The leaves first show yellowish or reddish spots which rapidly enlarge and darken in colour till rupture of the epidermis takes place, and they rapidly dry up. The fruit is thus altogether lost or much injured, while ripening of the wood is more or less interfered with. The remedies suggested are : sprayings with modified eau celeste, or amraoniacal copper carbonate (see p. 09)].^ (Edit.) P. cerasi (Bereng.) Clierry-nust on Primus Cerasus, P. Amygdalus, and I\ Persica. P. oenotherae Yize. On American species of Oenothera. P. giliae. Hark. On Phlox and Gilia. (U.S. America.) P. tanaceti D. C. On Tanacetum vulgare. (Britain and U.S. America.) P. sonchi Eob. et Desm. On Sonchus. (Britain.) P. end i viae Pass. On Cichoria Endivia in Italy. P. carthami Corda. On Carthamiis tinctoria. P. balsamitae (Strauss). On Tanacetum Balsamita. P. picridis Ilaszl. On P/'cris in Hungary. P. bistortae (Strauss) (Britain and U.S. America). On Polygonum Bisturta and /'. viviparum. The teleutospores have no papilla on their germ-pores. Soppitt {Grevillea, 1894) claims relationship between this species and an Aecidium on Conopodium demtdatitm (Aec. Im7iii(])). P. mammillata Schroet. (U.S. America). On Pohfgomim Bistorta. The upper cell of the teleutospore has an apical thickening. P acetosae (Schum.). On Rumex Acetosa, R. arifolia, and R. Acetosella. Ludwig says it hibernates in the uredo-form. P. polygoni Pers. (Britain and U.S. America). On Polygoneae. P. rumicis-scutati (D. C). On Polygoneae. P. oxyriae Fuck. (Britain and U.S. America). On O.ryria. P. castagnei Thlim. On Apium graveolens in France. P. cicutae Lasch. On Cicuta virosa. 'Pierce (Journal of Mycoloriy, vii. , p. 354) gives an account of this disease as fountl in California, and describes application and results of various remedies. 356 UREDINEAE. P. stachydis D. C. On Stachys recta. P. argentata (Schultz). On Impatiens. (]>i'itain and U.S. America.) P. Berkeley! Pass. On Vi)ica. (Plowright distinguishes also 1\ rincae.) (Britain.) (4) Uredospores absent or only rudimentcoy. The other spore- forms — pi/cnidia, aecidia, and teleutosp>ores — develop on the same host-plant. {Piiccinio'psis, Schroct.) : Puccinia tragopogonis (Pers.) (Britain). On Trago^wgon, Scorzonera, Podospcrmum, and Galasia. The leaves of diseased plants arc conspicuous in spring from their slenderness and pale colour. P. senecionis Lib.^ (Britain). The mycelium inhabits species of Senecio ; it probably arises from aecidiospores, and produces both aecidia and teleutospores. P. ipomeae Cooke. On Ipomea in U.S. America and S. Afi'ica. P. bunii (D. C). On Carum Bulbocastaniim and Pimpinella Sa.vifraga (Britain). P. srayrnii Biv. On Hmyrnum Olusatrum. (Britain.) P. trollii Karst. On Aconitum Lycoctonum and Trollius europaeus. P. Valerianae Carest. On Valeriana officinalis and Centranthus Calcitrapa. P. liliacearum Duby. On Ornithogahim, Scilla, and Oagea. (Britain.) (5) Teleutospores cdone produced ; they hiher^iate in dead host- rernai/is {]\[icropucci7iia, Sclrroet.) : Puccinia fusca (Eelhan.). (Britain and U.S. America.) Anemone-rust. The brown spore-patches of this fungus occur on various species of Anemone, Thalictrmn, and Pidsatilla. Attacked plants of Anemone nemorosa (Fig. 190, 6 and 7) have their leaves much altered, the petioles being abnormally long and the laminae much thickened, with narrowed segments, and conspicuously pale- green. The teleutospore-patches form chocolate-brown spots on the lower surface of the leaf, and stripes on the leaf-margins. Flowers are rarely developed on diseased plants ; Fentzling, however, found flowering plants with aecidia on tlie leaves ; three of the perianth-parts being stunted. The same investi- gator found a few anatomical changes in deformed plants ; in petioles the middle one of the three vascular bundles normally present was larger than those on each side of it ; in the dis- eased lamina the ])arenchyma-cells were enlarged, while inter- iDietel, Iledwiyia, 1891, p. 291 ; also Ze'itschrlft f. Pflnnzenlcrankheiten, 1893, p. 258. " ' J PUCCIMA. 357 cellular spaces were more nuiueroiis and also larirer. Other minor differences are also given, but there seems to have been Fio. IttO. — Ananone-RMt. 2 and 3, Normal plants of Anemone ranv.nculoides. 4, Aicidium pv.nclo.luiu on Anemone ranv.nculoides ; aecidia on the lower surface of the leaf; the plants are abnormally elongated, and the leaf-segments are smaller. 6 and 7, Puccinia fusca on Anemone nemorosa; the plants remiin small, 6 is completely deformed, 7 partially. 1 and 5, Aecidium leucospermum on Ammone ncmorom ; the plants are abnormally elongated and the leaf -segments smaller, (v. Tubeuf del.) 358 UKEDINEAE. some confusion between plants infested with this Paccinia and those with species of Accidium. The changes induced on anemone by either Aecidimn leucosper7mim D.C. or Aec. punctatum Pers. are quite distinct (Fig. 190). Kic. VM.—Pucclnia >-i/«s on Red Gun-ant (Ai6(.< rulirum). Tcloutospoi-o-patch on leaves and fruit, (v. Tubeuf i)hiit.) P. singularis Magu. On Anemone ranunruloides iu Austria and south-east of Europe. The teleutospore germ-pore is situated at the centre of the hiteral wall of the lower cell, thereby distinguished from that of /'. fnsra. P. atragenis Ilaussni. On Atragene alpina. P. thalictri Chev. On sj^ecies of Thalictnim. (Britain and U.S. America.) PUCCINI A. 359 P. Fergussonii Eerk. et Br. On Viola pahiMria, etc. (Britain and U.S. America). P. alpina Fuck. On Viola hi flora. P. geranii-sylvatici Karst. On Geranium sfjlvatioim.^ (U.S. America.) P. Morthieri KOrn. On Geranium. P. Holboelli (Horn.). On Arabis Holhoelli and Erijsimum narcissifolium in ])enmark and U.S. America. P. drabae Riul. On Draha aizoides. (U.S. America.) P. dentariae (Alb. et. Schwein.). On Dentaria hulbifera and D. enneaphjlla, causing pustule-like outgrowths on the leaves. P. ribis (D. C.) Currant-rust. On Rihes rubrum, li. nigrum, R. alpinum, R. Gro!i., 1890, j). KiT. -Sadebeck, Forstl-uaturwi.'is. Zeitnchrijt, 1895. M. \A'aril, SessionaJ Pape7-'s'- XVII., Colon\l)o, 1S81. ^^Dietel, Bcrlchte d. deuf-sch. holan. Ges., 1895, p. :r.i2. ^Bibliography and Revision, by G. Massee, GreviUea, xxi., 189;i, p. 111., 362 UREDINEAE. points. The so-called aecidia are really a form of uredo-sori ; they occur as thick cushions and cause thickening or twisting of the leaves and petioles. T. filipendulae (Lascli.) (Britain). On Spiraea Filipendula. T. echinatum Lev. occurs on Meum ; teleutospores alone are known (U.S. AnuTica). T. clavellosum Beik. On leaves of Aralia in the United States. Phragmidium. Teleutospores multicellular, the individual cells forming a single series ; tliey show a variable number of germ-pores. The Fig. 194. — Phrdf/riiidhim sitbcortichim on a Rose leaf. The black spots are teleutospore- patches on the under- surface of the leaf. (v. Tubeuf del.) Fl(j. 103. — TriphragnuuM ulmnriae on Spiraea Uhiutna. Germinating teleuto- spore, with proniycclia and sporidia. (After Tulasne.) teleutospores are produced in loose patches. The aecidial patches have no covering, but are surrounded by club-shaped paraphyses. The genus frequents only Eosaceae. On species of Bosa:'^ Phragmidium subcorticium (Schr'ank.). Teleutospores, uredospores, and aecidia on leaves of wild and cultivated roses. (Britain and U.S. America.) Phr. tuberculatum J. Midi. All the forms of spore occur on Rosa (xviiiiw. Phr. fusiforme St-hrot. M'lu: rosae-alpinae (D.C.)]. On Rosa alpuia (Britain). Phr. speciosum (Fr.). On North American roses. Phr. devastatrix Sor. On roses in Asia. ' J. Miiller, " Die Rostpiize d. Rosa. u. Rubus-arten," Ber. d. 'detitsch. botun. Ge-s., 188"). PHRAGMIDIUM. 363 On species of Potent ilia : Phr. fragariastri (1). C.) (Britain and U.S. America). Phr. potentillae (Per.s.) (U.S. America). Phr. tormentillae Fuck. (Britain.) Phr. papillatum Dietel, from Siberia. Phr. nepalense Baicl. and Phr. laceianum Barcl. in India On species of liuhus : Phr. rubi (Pers.) (/'/a: l»dhomm Schlecht.) (Britain). Phr. rubi-idaei (Per.s.). On leaves of raspberry. (ihitain and l".S. America.) Phr. violaceum (Schultz) (Hritain). Phr. rubi-miniatum J. .Miill. Phr. albidum (Kidni). Phr. quinqueloculare Barcl. Phr. octoloculare Barcl. Phr. Barclayi Dietel, from Hima- laya. Phr. gracile Farl., America. And other species. On Sanguisorha : Phr. sanguisorbae (D. C.)". On SanguixorhK 'iiiinor. (pjritain.) Phr. carbonarium (Sclilecht.) (Ijritain). This species has also been placed in a separate genus Xenodochus. It occurs on San- guisorha. Uredospores are want- ing ; the teleutospores form firm black crusts ; the aecidiospores form chains ; and the paraphyses are club-shaped. Diseased leaves and petioles ure thickened and bent. Wakker'.s investigation showed : a slight enlargement of parenchymatous cells and rupture of epidermis on spore-formation ; a diminution in the intercellular spaces and in formation of collenchyma and sclerenchyma ; a suppression of all production of chluropliyll and calcium o.xalate. Fig. 195. frutkoeus. lUiViii ruhi from Hubus erical iimiuvture te- leutospore, and two well-developed and germinating ones. (After Tulasne.) Melampsora. Teleutospores dark and unicellular, in some cases niulti- celhdar l)y formation of new walls, generally in a vertical 364 UREUINEAK. direction ; their sori form dark spots which break out from beneath the epidermis. The yeHow uredospores have a coat beset with fine spines, and are given off from sori which may or may not be enclosed in a peridium. The sori of the aecidium-stage have no peridium, and are known under the generic name of Caeoma ; they frequently occur on other hosts than tliose of the teleutospores. Pycnidia are produced in little yellow ]tatches. Melampsora tremulae Tul. (Britain). The sori of uredo- spores appear as little yellow protuberances on leaves or young shoots of Populus tremida. The dark-brown patches of teleuto- spores appear later on the under epidermis, and where they Fio. 196. — Caeoma 'pinitorquum. Section showing four pycnidia, from one of which (xj>) numerous conidia are being discharged. Caioma-pMches are developing beneath the cortical layer, as yet unbroken. (After R. Hartig.) occur in large numbers, an early fall of the leaf may result. The teleutospores hibernate in dead leaves on the ground. In spring the sporidia germinate and infect young shoots of Pinus sylvcstris, producing the disease known as Caeoma jnnitorquMm} This disease attacks pine-seedlings, appearing generally on the needles. It is most frequent in plantations from one to ten years old, rarer in those of ten to thirty years, and not as yet observed in older. Pinus sylvcstris is most commonly attacked, but it has also been observed on Pinus montana in Jiitland. After formation of the Caeoma --psitches, the young thin shoots generally die off, but thicker ones become twisted at the place attacked, whence the name " pine-twister " commonly given to this disease. If the leading shoot be attacked, the seedlings may succumb altogether. The disease develops rapidly, ' R. Hartig, mchfi'je Krankhcitcn d. Wahlhamne, 1S74. MEL AM PSORA. 365 particularly in a damp and cold spring, and may prove ver}- destructive if it appears for several years in succession. The mycelium evidently perennates in pine-shoots, and produces new Caco7na-]intehes year after year till death of the host results. It grows iutercellularly especially in the rind parenchyma, but also in the medullary rays of wood and bast ; the contents of the host-cells are absorbed by means of short lateral haustoria. Q I; Fio. 197. — C'tuoma pinitonjuum. Portion of CVooni'i-patch (enlarged). /', Cortical cells partially absorbed or mncli compressed ; 0, ba.sidi:i from which spores (<■) are abjointed in succession : the younger witli delicate walls and separated by membranous Lamellae, which disappear on formation of the spore-coats (S'. pruinosa X daphnoidcs, whose leaves are more hairy, a property which seems to protect them from spores. The following species have only uredospores and teleutospores, related Cdcom a -ioriw^ being unknown : M. lini (Pers.) (Britain and U.S. America). Flax-rust. The uredo- and teleutospores occur together on Linv.m. This may inflict serious damage in tields of cultivated fla.x. M. sorbi (Oudem.). On leaves of Pi/rtis Aucuparia and P. torminalis. Dietel ^ has recently placed this as the single species of a new genus Ochrosiwra. The light-yellow spores are at first one-celled, but before the death of the host-leaves they divide into four (rarely three) cells, each of which gives off' a sterigma with a single sporidium. In these points the spores follow the develop- ment of Co/cospormm ; the sporidia, however, are quite different, they are spindle-shaped, 22-2 5^t long and 8/w broad. Fic. 201.— .V(r?'/)ii/).()r.ski regards the Uredo as a Catoma-iovm. '-De Bary, Botaii. Zeitmiij, 1879. CHRYSOMYXA. 379 occurs on Ledum imludrc. It is difficult to distinguish from the preceding species, and causes the formation of similar aecidia on spruces in Northern Germany and other parts where Rhodo- dendron is not indigenous. Its uredospores are also capable of hibernating and of propagating the fungus where spruce is absent. Chr. himalayensis P.arcl. occurs on leaves of Rhododendron arhoreum in tlie Himalaya. .^^M^Ql^km L^. ¥i Fk;. 2\l.—Chriigomyxa rhodoclmdri. Teleuto- spore-sorus which has ruptured the lower epi- dermis of a leaf of Rhododendron hirsutum. The teleutospores are pluricellular, and one of them has germinated, giving a promycclium with .sterigniata, from which little sporidia are being abjointed. (After l)e Rary.) Fl<;. •2V2.—Chri/somi/xa rhododmdi-i on Spruce. The needles are beset with aecidia ; discoloured jiarts of them are shown black, the normally green being left white, (v. Tubeuf dpl.) Chr. abietis (Wallr.).i Needle-rust of spruce. This is parasitic (•11 the spruce (Picea cxcclsa), and is found on the Alps up to an elevation of over 1700 metres. About the beginning of May the hibernating teleutospores produce promycelia and sporidia. The latter germinate at once, and the germ-tubes make their way through the epidermis into young unfolding needles. The mycelium is well-developed and lives inter- cellularly, sending haustoria into the host-cells ; it contains yellow oil-drops, so that by the end of June needles contain- ing it exhibit yellow-coloured stripes. For the remainder of the year reddish-yellow elongated teleutospore-cushions are ^ Reess, Botan. Zeitiutif, 1865; Die Ikostpilzfonnen cl. deulxrhen Conifireu, 1S69. Willkomm, Die mikrosropiwheu Feiude dcii Wa/des, 1868. 380 UKEDINEAE. formed, and in this condition the funuiis hil)ernates, to develop further in the following spring. It is only in very dry cold winters that the needles dry up and fall off; as a rule they remain on the trees. About the beginning of May the spore- cushions break through the epidermis and give off multicellular teleutospores, which are as a rule branched. Thence arise the four-celled promycelia, with sterigmata, from which a single sporidium is abjointed. Diseased needles remain green except in areas inhabited by mycelium ; yet needle-cast soon follows liberation of the fungus-spores. Starch is laid up in large quantity in diseased needles during the first summer, but is com- pletely used up again by the mycelium for the formation of the teleutospore-patches, Spruces may suffer considerably from loss of foliage induced by this fungus, yet the risks are by no means so great as in the case of Cliryso- onyjxi rhodoilendri where the whole existence of the plant is endangered. Uredospores are unknown for this species and an Aecidium stage has not as yet been discovered. Eeess has shown experi- mentally that the teleutospores germinate directly on spruce witliout intervention of an aecidial stage. Chr. piceae Bare. On needles of Picea morinda in India. Chr. empetri (Pers.) (Britain and U.S. America). Uredospores on Eiapctrum 'nigrum. Caeoma empetri (Pers.) is the aecidial form. Chr. pirolae (D. C.) (Britain and U.S. America). Uredo- and teleuto- spores on Pjirold. Aecidia unknown. Chr. albida Kiilui. On Ruhus fruticosus in Germany and U.S. America. Fio. ilZ.—ChrysoMyxa abictis on Picca cwilsu. The sori occupy the middle portion of each needle, which is in con- sequence yellow, while the apex and base are still green, (v. Tubeuf del.) Cronartium. Teleutospores unicellular and remaining attached togetlier in tlie form of a long coiled process; they germinate i7i aitti and give off sporidia. The masses of teleutospores arise on the place formerly occupied by a uredospore-sorus. The ovoid uredospoi'es are abjointed from short stalklets enclosed in sori with a short peridium. Aecidia are developed on other JRONARTIUM. 381 host-plants, and several species produce blister-rust on the bark of species of pine. Cronartium asclepiadeum (Willd) (U.S. Anierica). I'redo- and teleutospores occur on Ci/uanchum Vincetoxicum (perhaps Fig. 214. — Cronartium asdcpiiuhurn on Cynanchum Vincetoxicum. The urudo- sori show as spots, the teleutospore-sori as processes on the leaves, (v. Tubeuf del.) also on Gentiana aschyiadca). The aecidial stage, known as Peridcrmium Cornui Eostr. et Ivleb. produces a blister-rust on the bark of Finus sylvcstris. Fio. 215. — Cronnrtium rwlepindtuin. Section of a C'l/nanck urn leaf. The leaf- parenchyma is permeated with mycelium, and sori are formed on the lower epidermis. A, urcdo-sorus ; B, teleutospore-sorus, many spores of which have germinated and given off promycelia with sporidia. (v. Tubeuf del.) Brown spots may l)e found on the leaves of the Cywiarhum'^ during July, August, and September (Fig. 214). On examina- tion of the spots with a lens, the leaf-epidermis will be found ^ A very common plant in Europe though not indigenous to Britain. (Kdit.) 382 URHDINEAK. pierced by a circular opening under which lies the yellow uredospore-patch of the Cronartium enclosed in its peridiurn. The ovoid yellow uredospores have a coat beset with short spines and are abjointed singly from short cylindrical sporo- pliores (Fig. 215). From the uredo-sorus there next arises a protuberance which lengthens till it forms an elongated slightly curved brown cone or column consisting of cylindrical teleuto- spores firmly built together (Fig. 215). The teleutospores germinate without becoming detached from the mass, and produce a four-celled promycelium with small sterigmata from which globular sporidia are abjointed. The sporidia on reach- ing the branches of Scots pine produce in its bark at first pycnidia, later aecidia. The pycnidia (spermogonia) give off" yellow drops of liciuid with a characteristic odour. The aecidia are yellow thick-walled sacs ; their spores are set free in spring and infect young plants of Gynanchum. Since the sporidia of the Cronartiuvi-sldigQ. are shed by September, tlie fungus would seem to hibernate only in the form of mycelium in the branches of pine. The effects of this fungus on the pine will be considered along with those of Pcridermium inni, another blister-rust of pine closely resembling this species (p. 4 1 1 ). Cr. ribicolum Dietr. Uredo- and teleutospores are developed towards the end of summer on leaves of various species of Ribes (e.g. Rihes nigrum, ruhrum, aureum, aljmuim, sanguioieum, americamim, rotundifolium, setosum, and Grossularia). The aecidium-stage {Peridermium strohi Kleb.) forms the blister-rust of the l")ark of Weymouth pine (Finus Strohis). Pycnidia appear in the summer of infection ; the aecidia a year kter. Externally this bark-rust resembles that of Peridermium Cornui and P. pini on the Scots pine. It may cause con- siderable damage to Weymouth pine both in nursery and plantation.^ It is probable that other two forms of Aecidium are identical with this, viz., that on Pinus Lamhertiana in America, and P. Cemhrri especially in Eussia. Cr. flaccidum (Alb. et Schwein.) (Britain and U.S. America). Uredo- and teleutospores on Paeonia, causing tlie leaves to dry 1 Magnus (Gartenflora, 1891) has pointed out that both the Cronartium and the Peridermium are unknown in America, the home of the Weymouth pine. CROXARTIL'M. 383 and curl up. In some districts very common. Aecidial stage unknown. Gymnosporangium.^ Teleutospores bicellular and furni.slied with stalks which have gelatinous walls, so that the spores come to form part of a gelatinous mass.^ The first-formed teleutospores are thick - Fig. 21G.— &>)„«os;)o, the spore-cjishions. 4, others are thick-coated. iian clo.riiiuiiifoi-iiii. 1, J, ■:. M.i-i - m .u v. h.|.in.-nt of . Isolated spores (enlarged); ■', is thin-coated, the Germinating .?pore with proniyceliuin abjointing sporidia (.S). 9, A germinating sporidiuui. (After Tubeuf.) walled, the succeeding ones are tliin- walled. Uredospores do not occur. The aecidia have a thick peridium. The teleuto- ^ V. Tubeuf: (1) CentraUilaft f. Baiter, k. J'arasidnkunth, 1S91 ; with a review of the current Literature. (2) "Infectionen mit (iymnosporangium." ForMch- natunviss. Zeitxrhrift, 1S93, p. 7r>. Woernle, " Anatomi.sche Untersuchungen d. durch Gymnosporangium-Arten hervorgerufenen Missbildungen," idem., 1894. Aniericaii Literature, see p. 40 L - The gelatinous substance is obviously well-adapted to absorb rain-water and so facilitate germination of the teleutospores in situ ; the sporidia pro- duced are then carried ofif by rain or liberated after the cushions dry again. 384 UREDINEAE. spores grow on needles and twigs of Coniterae, the aecidia on the leaves of various liosaceae (Pomaceae). Five species occur in Germany, but there are many in America. Gymnosporangium clavariaeforme Jacquin. (Britain and U.S. Anu-rica.) Tlie mycelium of this species perennates in twigs of Juniperus communis. Infection is brought about by aecidiospores. In the following year a swelling of attacked places is evident, and this increases till death of the host ensues. In spring, about the beginning of April, little light- yellow cone-like structures break out on the swollen places, f^' Fig. 217.— Section through a swelling on a sixteen-year twig of Juniper attacked by Gymnosporangium in its eighth year; three conical spore-cushions are indicated, also a cushion-scar with the scar- tissue. (After Woemle.) Fig. -ils. — Lmigitudiual section of a spore-cushion of Gymnosporanqhnn eld- vnriitcforme. Somewhat diagrammatic. (After Woernle.) and during rain swell up into long club-shaped sporophores, containing long-stalked, spindle-shaped teleutospores, some thick- coated, some thin. The sporophores swell and ultimately form a common mass in which the teleutospores germinate. The spores have four germ-pores, each capable of giving off a promyceliuin with pointed sterigmata producing sporidia, which are cast loose and distributed by wind. Germination of sporidia takes place on leaves, cotyledons, petioles, and shoots of various Pomaceae, where they may induce swellings or curvature, often to a considerable extent. GYMNOSPOR ANGI UM. 385 Experimental infection with teleutospores of Gymnoq-ior- arujivm davariacforme from Jnnipcriis communis gave the fol- lowmg results : -i Spore-fonii. (?) - R. lacerata, - lacerata, - On Host-plant. Crataegus Oxyaeantha, - - - ] Pyrus communis, Crataegus tomentosa, Crataegus Oxyaeantha, „ monogyna, Pyrus commtinis, - - . . Roestelia (?), - Pyrus torminalix, . - - - pyciiidia, Pyrus Malus, ----- „ Amelanchier, - - - - -It lacerata x, lacerata and aecidia Authority. Plow right. Thaxter. Eathav. Oersted. Thaxter. Crataegus Oxyaeantha, Crataegus grandifiorus, „ sanguinea, „ nigra, Cydonia vulgaris, Pyrus Aucuparia, Pyrus latifolia, Cydonia vulgaris, Crataegus nigra, CrataegxLS Douglasii, Pyrus Aria, Pyrus Aucuparia, - Pyrus communis. ill li \ wi :U th long tube-shaped -Tulieuf. j)eridia, - - - | lacerata^ - - - littk aecidia - only pyenidia, - only pycnidia, (pycnidia and (^ aecidia, [pycnidia and - -| with long tube-shaped J-Peyritsch. y peridia, - - - ; Jpycnidia and little ) t aecidia, - - - I - only leaf-spots, - - „ - no result, . . - j, .'pycnidia and aecidia with "j ( a long peridium, j Note. — Before the relationship of the teleutospore-forms was known, the aecidia were designated respectively : RoesttUa lactrata on Crataegus, R. rornula on Pyruii Aucuparia, and R. peiicillafn on Apple. The most abundant germination of sporidia takes place on species of Crataegus, and pycnidia (spermogonia) may make their appearance within fourteen days after infection on little yellowish sticky spots on leaves and shoots. By the time conidia (spermatia) have made their appearance, deformation may be far advanced. I did not succeed either in procuring germination of the conidia, or infection by means of them. 386 UREDINEAE. The aecidia are developed about the beginning of June, and on Crataegus their peridia in dehiscing split up into very narrow lobes so as to form a bristly tuft over the mouth of each aeeidiuni. On cultivating infected plants of Crataegus indoors, I found the peridia to develop quite abnormally ; they GYMNOSPORANGIUM. 387 may be as long as 10 m.m. and are bent like a horn (Fig. 219). A similar case is described by Barclay^ in which the peridia of aecidia on Rhamnus daliurica were very long if produced in dry weather, but short if in moist weather. ^ The aecidiospores are shed during the early part of June, and germinate at once on the bark of young juniper-twigs ; the mycelium growing thence into the spurs or branches to spread and hibernate, Teleutospores which germinate on Pomaceae other than species of Crataegns have apparently a normal mycelium, but produce pycnidia only, or aecidia with Fig. 220.— Cross-section through a swuUiiiy caused by Oi/.,<.,io^,jo,angium on Juniper-stem ; parenchyma with large cells and thin walls is present in abnormal quantitj'. (After Woernle.) peridia differing from those on Crataegus. My own experiments on the quince and mountain ash regularly produce pycnidia only. Wakker^ summarizes the anatomical changes induced in deformed shoots of hawthorn as follows : cork, collenchyma, sclerenchyma, and chlorophyll are not formed, lignification of the cells of medullary rays no longer takes place, and there are few intercellular spaces. Interfascicular cambium is not formed, while activity of the intrafascicular cambium is suspended at an early period, so that the vessels remain incompletely developed. The epidermis is irregularly formed and liable to ru{)ture. All parenchymatous cells undergo enlargement in a radial direction. Starch is stored up in large quantity, and the formation of calcium oxalate is diminished. 1 " On the life-history of Puccinia coronata var. /limalen.sis," Tranx. Liimcau Soc, London, 1891. -This probably is the explanation of tlie long peridia obtained by Pcyritsch And described by Magnus (/feWcA^e d. naturivis'i.madic. Verein, Inushrurk, 1892-9.3). •^ Prbujsheim's Jahrhuch, 1892. 388 UREDINEAE. The anatomical changes induced in diseased plants of Ji(nipcrm communifi by G. clavariaeformc were investigated by Woernle under my direction. His results were these: in vigorous branches, increased growth took place in the wood, bast, and rind ; in weakly and poorly-grown branches, the wood increased less in proportion to the bast and rind. The most marked increase took place in the bast, and to an almost equal extent all round the branches. This abnormal growth absorbs so much mm ■4 '"^)/g Fio. 221.— Cross-section of :i tract of parenchyma in a malformed Junijier- twig. (After Woernle.) 1 ^P^fi Z=i(~J &m\ Fig. 222.— Radial longitudinal section through a zone of parenchyma similar to Fig. 221. (After Woernle.) water and plastic material that higher parts of the branch gradually die off, and dormant buds break out on the swelling. Increased growth results in increase in the number of medullary rays, while in tlie tangential section their height is increased from 2-10 cells to 10-20 and more; the wood parenchyma is also more abundant, and together with the rays frequently forms large masses of parenchyma in the wood (Figs. 220-223). The tracheae no longer follow a straight course, and numerous intercellular spaces appear between them ; the tracheal walls fre([iiently become thickened and have an increased number of GYMNOSPORANGIUM. 389 fissure-like pores in place of bordered pits. The wood-elements in cross-section are no longer round but polygonal ; the bast becomes very irregular, parenchyma grows rapidly, bast fibres remain thin-walled and have no longer a straight course. The mycelium fills the bast and rind, forming masses in the inter- cellular spaces ; it is easiest found in the tangential section. On tlie fall of the club-shaped sporophores, a scar is left and under it will be found a layer of cork many cells thick ; when new sporophores are formed in later years, they seldom break through the cork layer, but emerge tlirough some new por- tion of the bark. Gymnosporang-ium tremel- loides Jlartig^ on J ualpirus, rum- muiiU. The sporocarps of this species occur on the branches and needles; its aecidia — Roc- Mclia peyiicillata — on leaves of apple (Fi/rns Mains), Pyrus Aria and P. Chamacmesjnlus. This Rocstdia is externally very like that of G. clavaricu'formc on Crataegus. The markings on the cells of the peridium consist of somewhat wavy lines, not of short rod-like markings as in R. cornuta ; and the cells of the peridium are joined by a characteristic hinge-joint (Fig. 224, 19 and 20). The mycelium perennates in the rind of Junijjcru.'i communis and J. imna, causing thickening of the twigs and a premature death of the distal portion above the swellings. The chocolate- brown velvety spore-cu.shions break out between the bark-scales on the swollen places, about the middle of April (Fig. 225, l). The teleutospores are two-celled, the earlier formed ones being short, ovoid, and slightly pointed at each end, while the later ones are thinner-walled and often more elongated (Fig. 225, 6-10). Fici. 'iili.— Tangential longitudinal sec- tion through the parenchyma-zone of Fig. -220. (After Woernle.) ^Hartig, 7>>/»ease.s of Trees, English edition, 1894. Dietel, For-^tlich-iiatur- vAss. ZeiUchrifl, 1895, p. 348. E. Fischer, Heihcujia, 189.5, p. 1. 390 UREDINEAE. In ]\Iay or June the cushions swell up and become large brownish-yellow gelatinous clumps, dotted over with dark points, the teleutospores. Promycelia arise from one or more germ- pores in each spore, and give off basidia with sporidia (basidio- HJ^>6WKfe.v, /^ I Fio. 224. — Accklia and Piiniidia of various species of GyninoKporanyhim : G. tremelloides — 1 and i', aecidia on leaf of Pi/rus Aria ; 5 and 6, aecidia on leaf of Pyras Malus; 10 and 20, portions of the peridiuin of an aecidium from ii, showing the peculiar articulation of the cells. G. juniperiiium — 3 and U, aecidia on Pyrus Aucuparia; 7 and S. aecidia on Amelanchier vulgaris. 0. clavariaeforme— 9 a.nd 10, aecidia on Pyius latifolia; 11, 12, and Hi, aecidia on Crataegus Oxyacanlha, grown out-of-doors ; 7/,, the same aecidia, enlarged ; l.i, I'l, and 17, aecidia on Crataegus Oxyacanlha, indoor culture; IS, deformed twig of Crataegus bearing pycnidia. (After Tubeuf.) spores) capable of immediate germination. The gelatinous mass dries up from time to time, leaving a bright yellow scar on the swollen part of the host-branch. The sporidia germinate most easily on species of Sorbiis (Fi/r/'s). Infections with GYMNOSPORANGI UM. 391 },,• •iiidia, Roestelia (?), - (?) - - pjcnidia, Rostelia cornuta, - R. penicillata, R. penicillata, R. penicillata, spots, - thick spots, - pycniclia ami aecitlia, thick spots, - pyciiidia and aecidia, pycnidia only, pycnidia and awidia, Plowiigl Thaxter. Haitig. Nawaschin. Pevritsch Gymnos23orangium juniperinum L. and G. trcmclloides Hart, from twigs and needles of Juniperus comiminis produced : On Host-plant. Spore-form. Authority. Pyrus (Sorbus) Aiccuparia, - - Rostelia cornuta, - - Tubeuf. Aroma rotundifolia, - - - short aecidia, - - Rathay. Pyrus Mains, - - - - Pyrus {Sorb lis) Aria, Cydonia vtdgaris, . . . . Pyrus {Sorbus) Aucuparia, Pyrus Malm, - - - - . Amelanchier canadensis, - Pyrus {Sorbus) Aria, Pyrus Mains, Pyrus {Sorbus) Chumaemespilus, Mespilus macrocarpa, Pyrus communis, - . - . Pyrus {Sorbus) Aria, Pyrus {Sorbus) Aria x Chamaemesp., Pyrus Malus, Pyrus {Sorbus) Chumaemespilus, Pyrus {Sorbus) A ucuparia, Aronia rotundifolia, . . . ,, ^, Pyrus {Sorbus) torminalis, - - pytiiidia and spots only, Crataegus Pyracantha, . . - ,, ,, Cydonia vulgaris, - - - - „ ,, Pyrus Mahis, --'.-- Rostelia peniciWita, Formation of p}X'nidial spermogonia always of aecidia. This fungus is of practical import on account of its occurrence on leaves of apple-trees. Its attacks may be very virulent and widely distributed. Eriksson mentions that near Stockholm it is common on apples, and so virulent that many trees have every leaf studded with Roestelia. (American apple-trees suffer from Roestelia pirata, the aecidia of Gijmnosporangium macropvs and other species. ■ See p. 402.) Gymnosporangium juniperinum (L.) {G. conicnm Hedw.) (Britain and I'.S. Aniorica). This species, also frequenting Jtinijjeri/s eommunis, is distinguished by its shorter spores, which, as Dietel pointed out,^ have a colourless papilla over each germ-pore. The teleutospores are found on both twigs and needles, on the former, however, they are much smaller '^ Forstdch-natnrwiss. Zeitsrhrift, 1895, p. 378. - Rostinp. precedes that 392 UKEDINEAE. than those of G. tremelloidcs. Tlie aecidiospores — Roestclia cormda — occur on species of Pyrns {Sorhus)] they are much smaller than those of Rorstclia pcnicillata. The Roestclia themselves are long, curved, and horn-like, while the walls of the peridial cells are beset with short processes (Fig. 224). Where Pijrus Aucuparia occurs mixed with Pyrus Malus, it has been observed that Roestclia cornuta is confined . to the former species exclusivi^ly. The Roestclia is the cause of a CP> jv^. l''io. 225. — Gyiiinoaporangmm juniperinum and 6. ti-cmcUoides. 1, Young spore- cushions breaking through the bark ; 2, the same in swollen condition ; 3, gela- tinous cushion arranged to show its lower surface ; 4, Juniper-needle with three spore-cushions ; fi, young Juniper plant bearing cushions on its needles ; 6 to 10, spores of various kinds, to show the variation in size, shape, and thickness of wall ; 11, cell of a promycelium with a sporidium attached ; 1.', germinating sporidium. (After Tubeuf.) marked deformation of leaves, petioles, and even (though rarer) fruits of Pyrus Aucuparia and Aronia rotundifolia, both in the lowlands and mountains. I have produced Roestclia cornuta on Pyrits Aucuparia by artificial infection with portions of spore-cushions from twigs of juniper, and have observed a mountain ash in closed forest, with abundant Roestclia, directly beneath an overhanging juniper with diseased needles. GYMNOSPORANGIUM. 393 Woerule investigated tlie anatomical changes induced by tlie various Gymnosporangia frequenting the twigs and needles of Juniperus communis. In the needles the mycelium lives inter- cellularly, at first outside tlie endodermis, but later also penetrating within this. The sporogenous cushions originate on the upper surface of the leaf to right and left of the middle nerve, where the stomata occur and hypoderm is absent. At these places a cushion or stroma of pseudoparenchyma is produced and ruptures the epidermis (Fig. 226). This however is at once healed over by a cork-formation round the margin of the cushion, again to be ruptured as the latter increases in size, once more to be healed by cork-formation, and so on. In Fio. 220. — Comparison of («) normal .Jiniiiicr-nuudlc with one (li) bearing teleuto- spores of Gyiiinonjioraniiivm. In n the double outline indicates the hypoderm ; the central vascular l)undlc and an underlying resin-caual are shown. (After Woernle.) this way a corky layer is formed under the sporogenous cushion and gradually displaces it. If in a following year the cushion be again formed, the scar is ruptured and heals as before. Needles frequently remain in position for two, three, or four years, but most of them fall off in the first autumn, lender the sporogenous cushion the cells of the mesophyll increase both in number and size. In considering the twig-deformations, Woernle distinguishes the form assumed by the Gyinnosjjorangium on the needles, as just described, from a form which inhabits the thicker twigs. Both cause deformation of twigs, but their eilects differ as follows: " The needle-inhabiting form can only cause a .slight swelling extending almost regularly round the whole twig; the twig- inhabiting form, on the other hand, always gives rise to a very 394 UREDINEAE. marked swelling on one side only (Fig. 227). In the needle- form the swelling results from increased growth of the rind, with a simultaneous decrease of growth of the wood ; in the twig-form the growth of both wood and rind is much increased. With the twig-inhabiting form the medullary rays and wood- parenchyma increase, and at the same time become filled with mycelium (Fig. 228); whereas with the other form the medullary rays are at most only somewhat broader, and no mycelium can be found in the wood. The greatly swollen rind in the case Fio. 227.— Section of a nine-year twig of Juniper attacked by Gymnosjiorangium. The rind under the spore-cushion is much thickened ; the wood towards the same side is much broken up by tracts of parenchyma. (After Woernle.) Fig. 22S. — Tangential section through diseased wood beneath a spore-cushion. The wood- elements are much displaced by abnormal tracts of parenchyma. (Only one of the latter has been filled in, the others left blank.) (After Woernle.) of the twig-inhabiting form is due more to increased growth of the cortical cells than to increase of bast-parenchyma; in the needle-form, however, the swelling is the result of increase of the bast, especially of the bast-parenchyma. In twigs infected by the needle-form, the mycelium may be found all round, but it lias difficulty in making its way radially to the cambium; in the twig-form the mycelium, as early as the spring following infection, will be found to be in close contact with the cambium on the infected side, although it requires several years to pass round to the cambium on the opposite side of the twig. The mycelium and spores of the two forms differ little from each other." GYMNOSPORANGIUM. 395 , The strikingly characteristic cleavage of the wood by the overgrown elements of the medullary rays and the wood- parenchyma, in the case of the twig-inhabiting form, will be seen from the figures (Fig. 229). As already noticed, the sporogenous cushions are generally formed on one side. After Fig. 229.— Two sections from a swelling on a Juniper-bi-anch. a. From the middle of the swelling ; the rind under the spore-cushion is much thickened, and the wood is much broken up by tnicts of parenchyma. 6, Section from 2 cm. under a ; abnormal development of parenchyma in the wood has begun in the outer year-rings. (After Woernle.) the shedding of the cushion, a corky layer arises in the paren- chyma undcrnoatli it, and so a bark-scale is produced. Gymnosporangium sabinae (Dicks.). (Britain.) The mycel- ium hibernates chietiy in Ji'Jiijyerus Sahiiia (Savin), and induces swellings on the twigs. It also occurs on Jun. Oxyccdrus,^ ' I found this host-species near Fiunie. :596 UREDINEAE. Jun. virginicnw, and Jan. 2}hoenicea. (A reported occurrence on Finns hakpnisis is probably an error.) The sporogenous cushions are little dark-lnown protuberances which lircak fortli in sjirinp: from swellings, or on L;reen Fig. 2^il—Gi/iiinos/>orunpium xnbinae on twigs of Junipirux Sidjimi, at the time nf lilicnitiou of spores, (v. Tubeuf i>hot.) twigs and scale- leaves. These bodies absorb water, swell, and run together, forming transparent gelatinous masses (Figs. 230 and 231). The teleutospores resemble those of G. junipcrinum, but liave only four germ-pores ; they germinate on the gelatinous masses, and produce promycelia and sporidia. The latter germinate at once, chiefly on leaves of Pyrus com- munis. The pycnidia are produced on the upper epidermis as sticky yellow spots bearing darker dot-like pycnidia. The aecidia {llocstelia canccllata) are found in September on the under-surface of the leaves of pear, also on leaf-petioles, young shoots, and even on the fruits. The peridia differ from both OYMNOSPORANGILM. 39; the species already described in remaining closed at the apex, the spores escaping through trellis-like slits on the lateral walls of the peridia (Fig. 234). This fungus will not germinate on apple-trees, but on pears every leaf may be thickly covered with aecidia and pycnidia, and considerable damage to the crop thereby ensue (Fig. 233). Fig. 231. — Lougitudinalscctiou through a conical teleutospore-sorus of Gymno- sporangium Sabinae. (After Woernle.) Fio. 2;i2.— Teleutospores of 0. mbiiwr. The elongated thin-walled ones arc lighter in colour than the thick-walled. (After WoenUe.) Infections on various hosts with Gymno>ipumn(jium sabinae from JwiiiJem.s Sahina gave : Spore-form. Authoritv. I On Host-plant. Pyrus communis, Crataegus Oxyacantha, Mespilus gennan ica, - Pynis communis, Pyrus communis, „ Mic/iau.rii, „ tomentosa, Pyrus commicnis, Pyrus communis, Crataegus Oxyacantha, (0 Postelia cancellata. Plowrifrht. Oerstedand De lijiry. Ratliay, Tubeuf, etc-. Eeess. E. Fi.scher. Klebahn. ,, (uncertain). 398 UREDINEAE. The anatomical changes exhibited in diseased parts of pear- leaves have been briefly described by Fentzling/ He found a radial elongation of the. cells of the spongy parenchyma and an accompanying accumulation of starch. AVakker, about the same time, obtained similar results in the case of Crataegus Oxyacantha deformed by G. clavariaeforme (see p. 387). Wakker observed a diminished formation of calcium oxalate ; Fentzling, however, found increased deposit of the same salt, not only in the form of Fio. 233. — Gi/mnosporangiaiii sahitiac in the form of liotstcUa. canccllata on leaves of Pear. A few twigs showing the abundance of aecidia over the whole tree. (v. Tubeuf phot.) isolated crystals but as masses. Cork-formation was suspended in Wakker's case, while in Fentzling's a partial formation of cork was distinguishable beneath the epidermis. The increased thickness of diseased leaves- is due principally to multiplication of the spongy parenchyma, the upper layers of which frequently become more or less palisade-like. When pycnidia (spermogonia) are formed on tlic upper leaf-surface, the palisade parenchyma ^ Fentzling (lor. cit. ) and Peglion (Rivista di Patologia Vegetale, ii. ), also describe these alterations. GYMNOSPORANGIUJI. 399 of the spot in (question is either completely destroyed or trans- formed into irregular cells, separated by intercellular spaces. The anatomical changes in swellings (Fig. 235) induced by (I. sahinac on Juiii'pcrus Sabina were investigated by Woernle with the following results. Wood, bast, and rind are increased round the whole circumference of the stem. Along with the broadening of the year-rings, however, there occurs a change in the structure of tlie diseased wood. The same Fig. 234. — A few leaves enlarged from Fig. 233. The leaf to left hand bears pycnidia on red spots on the upper surface of the leaf ; the remaining le;ives bear aecidia on raised portions of their surface. Several aecidia still furtlier enlarged show the peridia dehiscing by longitudinal slits, (v. Tubcuf del.) tissues occur in the year-rings as already described for G. clavariaeforme, viz. thickened twisted tracheids, loosely connected together and with fissure-like pits ; medullary rays more numerous and broader ; the limits of the year-ring difficult to distinguish ; and a yellow pigment deposited in the walls of all the elements. A tissue of this nature may be found round the whole circumference of a twig even in the first year after infection, and regularly each succeeding year. Woernle only rarely found zones of irregular cell-formation like those 400 URKDINEAE. characteristic of G. clucariacformc. No mycelium occurred in the wood. A comparison of normal bast with that of infected twigs revealed clianges similar to those already described for G. davariavformc. In addition, it is to be noted that the thickened bast-fibres no longer occurred in closed masses, but were often completely absent in the first year after infection, while in all diseased twigs every intermediate stage exists between thin-walled bast-elements and thick-walled bast-fibres, such as never occur in the normal twigs ; in fact, many twigs had thin-walled elements only. Fig. 23.5.— Swelling from a branch of Juniperus Snhina attacked by Gymno- xporangiv.m Knhlnae. Dia- meter at thinnest part 1'7 centimetre, at the thickest lic.m. (v. Tubeuf phot.) Fig. 236. —Sections of a twig of Savin attacked by G. .mhinar. a, At thickest part of the swelling ; h, 3 cm. under a and normal. In a is shown one of the hollow teleutospore-cushions ; five cushion-scars ; in the second-year ring are two shaded zones of wood, chiefly composed of parenchyma. (x25.) (After Woernle.) The sporogenous cushions of G. sahinac are formed in quite a different manner from those of G. davariaeforme. Beneath each cushion the bast increases very rapidly and forms an out- growth, which is still further enlarged by the addition to its apex of six or seven rows of radially arranged cells, rounder and smaller than the bast-cells of the cushion. The mycelium penetrates between these outer cells, and forms over the whole cellular outgrowth a pseudoparenchyma from which the sporo- genous tissue arises. GYMNOSrORAXGIUM. 401 A sharply delined roiiiulisli scar of a light-yellow colour remains after the spores are cast. This is composed of a superficial layer of coloured pseudoparenchyma, with an under- lying scar-tissue of characteristic constitution. The latter con- sists of several layers of cork-cells extending from one edge of the scar to the other, separating the cushion from the twig- tissues. This scar-tissue is not broken through next year, but the new sporogenous cushions l)reak (tut through otlier parts (.f the bark (Fig. 236). G. confusum Plowright.i (Britain.) This is found on Jiinipirtis ^((hiiia along with G. sahinac, from which it is difficult to distinguish. Pycnidia and aecidia are produced generally on Crataegus Oxyacaiitlia and Cydonia vulgaris, rarely on Pyrus communis. The aecidia on Crataegus resemble those of G. clavariaeformc on the same host, and dehisce by the ruptured apex of the peridium. Tliose produced on Pyrvs communis are distinguished- from aecidia of G. sahiuof on the same host by dehiscing through the open apex of the peridium. Infections of Gym. confusum from Juniperus cummunis gave the following resiilts : On Host-plant. Authority. ^ , . , . 1 iivciiidia and aecidia with i , , .,-, • _ „ Cydona ndgans, - - M • ^^^,^^^,^^^. ^^^.^.^ . . J K. b ...ci.e, . Crataegtis O.vyacaiitlta, - „ „ „ >> Pyi'us communiii, - - „ „ „ » Cmtaeyns O.njacanth'i^ - .. „ „ Pl..\vi-i,tc/te.-i' Bi-nom oj Silrer i-V)- (summer condition). Tlie markciily negative geotroi>ic broom has its origin in ;x distinct basal swelling, (v. Tulieuf phot.) The various tissues of the witches' brooms also undergo considerable modification as compared with normal twigs. A thicker and softer bark is present, due to the parenchymatous cells of both outer rind and bast having enlarged in size and increased in number ; tbe cork layers are also abnormally in- creased. The same changes may be observed in the rind of the swellings, and to this their increased size must be chiefly ascribed. The wood both in twigs and swellings is much increased; the year-rings however are very variable, sometimes they are broader than the normal, again they may be diminished or even altogether wanting ; where however the wood decreases, there the bast increases in proportion. This lack of uniformity AECIDIUM-FOKMS. 40/ ill the growth of the wood disturbs the elements, so that they are irregularly developed and more or less twisted.^ A mycelium inhabits the tissues of abnormal twigs and cankered swellings. It grows in the intercellular spaces of the rind, between the bast cells and outer parts of the wood, and derives nutriment by means of haustoria : these either bore through the cell-walls, or only press closely against them so as to cause depressions. Spore-formation takes place on the needles of the witches' brooms. The pycnidia (spermogonia) are produced on the upper side beneath the cuticle and emerge through it as little yellow points. The conidia (sper- matia) are tiny globose colourless bodies. The aecidia come later during June and July in irregular rows on the under side of the leaf. Their peridia break out as low dome-like structures, the apices of which rupture irregu- larly t(i allow escape of aecidio- spores. In spite of numerous infections, De Bary was unable to observe the penetration of a germ-tube into needles or twigs of silver tir. "Weise believes that infection of the fir takes place on twigs which have just emerged I'rom the bud. As a preventive measure, all witches' Ijrooms should be cut off before spore-formation begins, and stemswith canker-wounds should be removed during forest-tliinning. For further details the monograph of Heck may l)e consulted. Aecidium strobilinum (Alb. et Schw.)'- (Ihitain). Spruce- . — A' rkUvm uliohidntim on a Spr .0)1.. (V. Tubeuf phot.) ' Note — FiutliL-r (lt't;iils of the aiiiitomiciil changes iiidueed in tlie tissues of tliese witches" brooms may 1)6 obtained in tiie ( Jerman edition of thi.s work (pp. 4l'0-4'21), or in the original tliesis Ijy Hartmann, {Ana/07)i. Vcr(ileiiri.^ and other species. (See Puccinia agrostidis, p. 349.) Aec. actaeae (Opiz.). On leaves of Actaea spicata in Europe and America. Aec. barbareae D. C. On species of Barbarea (Britain). (See Pure. fr.-, The peridium. (After R. Hartig.) young plants soon succumb to attack, the struggle witli old trees may go on for years. Fresh infection of older stems occurs generally in tb.' biglicr parts of the tree, where the bark is still thin. Pycnidia (spermogonia) are developed between the rind- parenchyma (periderm) and cork, generally towards the margin of diseased spots. The conidia emerge from the ruptured cork-layers of the bark as a honey-sweet liquid. H. Mayr states that this liquid is given off in such quantity from species of Pcrulerwiinii in Japan, that it is collected and eaten bv tlie natives. 4U UKEDINEAE. The aecidia appear in June as wrinkled yellow sacs emerging from tlie bark of swellings. They continue to develop in succession for years on the living parts of attacked branches, but according to Hartig they cease to make their appearance on old stems, even when a mycelium is present. This disease is the cause of great damage to pines, especially where planted as pure forest. One case is recorded ^ of a forest near Kohlfurt where 90 per cent, of the trees in an old plantation were " stag-headed " on account of a deficient /f^ k /^s«^ - F % v.J^ - llfc '^ -^,m Fio. 2iS. — Fi>rid(rm!um pin!. Section through a diseased stem ot Pine showing the gradual killing of the cambium bj' the fungus, (v. Tubeuf phot.) supply of water in the crown accompanying attacks of this fungus. Until more is known of its life-history, preventive measures cannot be well extended beyond cutting down infected trees. The following species of Peridermium have been observed on species of Pinus: A. On the needles: Peridermium oblongisporium Fuck, (now Co/eonporm/n seneclo/iis) on J'iHHS s//U-estriii and /'. (iii:cuf phot.— the specimen presented by Prof. (Jrasnianii of Tokio.) P. brevius Barcl. On Pinus excelsa in India P. complanatum Barel. On Pinus longifolia as needles. 11. On the rind or burk : PeridermiumCornui Rcstr. et Kleb. (now Cronartium nsclepiadeum, p. 381). On Pinux xi/fri'stris. P. strobi Kiel I. (now Cro- itiii-tium n'birolK, p. 382). On Piniis Strob us, P. La mhertia na, (and P. Ccmbra). P.pini(VVilld.). On Pinus s>/h-estris. (Britain and U.S. America.) P. orientale Cooke. On Pimis rigida and /'. virgini- ana in America ; also P. longifolia in India. India: on rind a.s well I Flo. 250.— /'•<(rf«niu«m giqanUvm on Vinm douiflora from Japan, (v. Tubeuf phot.) 416 UREDINEAE. P. Ravenelii Tliiiin. On Pinti^ (t,istriiU.< in Ndrth Auu-iira (probably a varifty i>f /'. oldongi.^porium). P. deformans Mayr. On I'iims viitii^ in Anifiiea. P. giganteum (Mayr). On Pi/iuK de/tsiyiora And J'. T/iunbe/r/ii iu J ii\ydu. Tills causes wry conspicuous deformation of its host (Figs. :249 and 2r)()V P. complanatum Barcl. On Pitms longifoU'i in India. The fnlldwiiiu- s])ceies frc(|uent other hosts: Peridermium conorum Thlini.^ This aeeidiuin first t'oinul by De IJarv in Thiiriu^ia, has recently been reported in Denmark, liussia, and America ; also in Upper Bavaria Ijy v. Tubenf in September, 189"). It takes the form of two large aecidia, which make their appearance on the outer or inner side of the cone-scales of spruce. The white peridia break througli the epidermal tissues which then remain as a brownish sheath around each ruptured peridium (Fig. 251). The spores are separated by inter- mediate cells, and their outer coats are studded with poly- gonal warts. The cone-scales bearing aecidia contain a very large quantity of starch. Tel- eutospores of the species are unknown. Peridermium coruscans Fries.- The mycelium of this fungus seems to perennate in twigs and buds of spruce. Twigs unfold from the bud as deformed, shortened, cone-like shoots bearing very short broad needles of a pale colour. The aecidia are produced on the deformed needles as broad lineal cushions with white peridia. They originate under the epidermis which tliey rupture, and break out on one side of the needle. 'Reess, Bosfpihformoi, 186!>. -Rostrup, VUlnisL (,'eld: For/iniHl/., 1SS4. jper Fio. ih\.—Ae.cidiuyii conoi-um-piceae. per, Peri dium ; x/>, spore ; sw, intermediate cells ; .fptr. sporophore ; m, mvcolinm ; pm.t, prosenchvma, (After Reess.) PERIDKRMIUJI. 417 The soft hypertrophied shoots are eaten. They occur chiefly in Scandinavia, but recently were observed by Gobi and Tranzschel in the neighbourhood of St. Petersburg.^ Fio. 252. — Aecidium coruxcans on malformed shoots of .Spnice. The compact abnormal shoots thickly covered with white aecidia contrast strongly with the normal portions, (v. Tubeiif phot, from material presented by Prof. Fries, Upsala.) P. Engelmanni Tlniiii. Ou coiie.s of Picea Smithiana. (U. S. America.) P. piceae PJarcl. On needle.s of Picea Smithiana. P. Peckii Thiiiu. On needles of T.mga canadensis (U.S. America). P. balsameum Peck. On needles of Abies halsamea (U.S. America). P. ephedrae CVjoke. On Ephedra in U.S. America. P. cedri 15arcl. On needles of Cedrus Deodara in India. P. Balansae Corn. On leaves of Davimara ovata in New Caledonia. 'Also reported at Haslemere (Britain), Grevillea, xix., 189rnle's researches on Gymnosporaiujiam. The parenchymatous groups of cells in the wood appear to the naked eye as brown spots. They are permeated by a vigorous intercellular mycelium, which sends off large haustoria into the adjacent cells. Caeoma laricis (We.steiiil).i On needles of Larir. (Britain.) C. orchidis A. et 8. On orchids. (Britain.) C. chelidonii Magn. On Chelidonium majus (U.S. America). C. fumariae Lk. On Conjdalis. C. euonymi ((hnel.). On Euonymus eiiropaeus (Britain). C. confluens (Pers.). On Riles alpinum, R. rubrum, etc. C. nitens (C. luminatmn) is the well-known Blackberry-rust so common in the United States. It is probably a form of Puccinia Peckiana.'^ C. aegopodii (Rebeiit.). On Aegopodkim Podagraria and Chaeroph>jJlnm iiromadcv./it. C. ligustri (Rabh.). On Ligustritm vulgare. C. ari-italici (Diiby). On Anim maculatuvi. C. alliorum Link. On Allium ursinum, A. olemceum, etc.'' C. saxifragae Strauss. On Saxifraga gramdata? C. mercurialis QIart). On Merciirialis perennis.^ ' Tiiis and most of the other species are only stages of some Mdampsom. -Clinton, Botanical Gazette, 1895, p. 116. •' These three species are given as British in Plowrighfs 'Uredineat.' (Edit.) 420 UREDINEAE. Uredo-Forms of uncertain relationship. Uredo agrimoniae (J). ('.). On species of Agrimonia (Britain and U.S. Anierioa). Dietel regards it as related to Melampsora (Theeospora) affri- monide. U. Muelleri Scliroet. On Hitbus frnticosus (Britain). U. symphyti D. C On Symphytum officinale (Britain). U. phillyreae Cooke. On PhiUyrea media (Britain). U. macrosora Dc Toni. On Epilohium tetragonum (U.S. America). U. vitis Thiini. This species first attracted notice as a disease- ])roducing fungus in Jamaica in 1879, but it had been found previously in the United States. It causes spots on the upper surface of leaves.^ U. fici Cact. On Ficus Carica in Italy and U.S. America. U. quercus (Brond.). On species of Quercus (Britain and T^.S. Amei'ica). U. iridis. On many species of Iris (Britain). U. glumarum Rob. On Zea Mais in Belgium and England. U. sorghi Fuck. On Sorghum halepense in Greece ; (compare with Uromyces and Fuccinia on the same host.) U. g-QSsypii Lager.- This has been observed in South America causing a rust on cotton-jjlants and injuring the yield of cotton. It appears as small purple-brown spots ; the spores are oval and yellow. Uredinopsis.' [This is a new genus found by Magnus to contain several Uredineae parasitic on Ferns.* The aecidial stage is unknown. The uredospores are abjointed singly from the ends of sporo- genous hyphae ; they are unicellular and without germ-pores. The uredospore-sori are enclosed in a pseudoperidium of elon- gated tubular cells. Unicellular teleutospores (?) are given off from sori similarly to the uredospores. Pluricellular teleuto- spores are developed from the mycelium in the intercellular spaces of the host-plant, never from crust-like sori. On germination four-celled promycelia with spherical sporidia are produced. Uredinopsis fjlicina (Niessl.) Magn. On lower surface of fronds of Phegopteris {Polypodium) vulgaris, causing death. Ur. struthiopteridis Stoermer. On sterile fronds of Strnthiopteris germanica. Ur. pteridis Diet, et Holw. On Pteris aquilina.'] (Etlit.) ^ Ma.ssce {(IrtvUlta xxi., p. 119) states this species to be identical with U. Vialae of Lagerheiin (Revue gen. de Bolanique, 1890). - Lagerheim, Journal of Mycology, vii. p. ' 48. •'Dietel, ''Uredo polypodii (Pers.)" Oesterreich. ho/an. Zeitschrift, 1894; also " Der Gattung Uredinopsis," Ber. d. deutsch. botan. Ges., 1895, p. 326. ■* These host-plants do not come strictly within the scope of tliis \\ork, but a short note on the genus is necessary. (Edit.) BASIDIOMYCETES. 421 BASIDIOMYCETES. The sporophores, known as basidia, are structures with a ;ite on apple, (^uercus coccinea, and a ])ahn. Th. perdix Hartig, a pai'asite on oak-wood. {See Stereum fnistuloi>u/n.) Hehcobasidium Mompa. Ichik.- This is injurious to the mulberry tree near Tokyo, Japan. It first attacks the roots, and in consequence the growth of shoots is arrested, the young leaves die off, and gradiially death of the tree follows. The mycelium permeates the tissues of the host, and forms an external velvety coating of basidia. Stereum. Sporophores generally diirerenliatud into three layers, and forming leathery or woody encrustations, or flattened hemi- spherical structures attached by one edge only. Stereum hirsutum (W.) Fr. White-piped or yellow-piped oak. (Britain and U.S. America.) A very common fungus, occurring as a saprophyte on dead branches, on boards, and posts of various kinds of timber, as well as parasitic on living wood, particularly on oak. The sporophores first appear as crusts, later they become cup-shaped ; externally they are brown and roughly hairy with acute yellowish margins. The smooth hymenial layer is orange- red and marked l)y zones. Between the sterile leathery sporo- phore and the hymenial layer there lies a firm white intermediate tissue. Kialloway, Journal of Mijeolowj, vi., p. 113. -Nobujiro Ichikawa, "A new hymenomycetous fungus," Jour, of Collefffi of Science. Imperial University, Japan, lcS90. 430 BA8IDI0MYCETES. E. Hartii;- ^ has investigated in detail the phenoineua accom- panying the \V(jod-destruction in tiie oak. This begins in the branches and extends in wliite or yellow concentric zones throughout the stem, so producing that appearance which has given rise to the name " tiy-wood." Portions of the wood appear only white-striped, other parts have a more regular yellowish- white colour. In the white strips the wood has been transformed into cellulose and the middle lamellae of the walls dissolved out ; that of the yellow parts has not undergone this transformation into cellulose, liut the destruction has begun from the cell-cavity. Fio. 200. — .SVt/'«i(i/i jrusti^losum. Destniction of Oak-wood. Longitmlinal section showing the brown wood with isolated hollow spots containing white mycelium, (v. Tubeuf phot.) Stereum frustulosum Fries. (Thelephora perdix Hartig).- (Britain and U.S. America.) The sporophores form greyish- brown plate-like crusts with concentric markings ; they are small, never exceeding tlie size of a finger-nail, but generally occur in numbers together. The hymenial layer is composed of club- shaped basidia beset with hair-like outgrowths ; some of the basidia produce four spores, others are sterile and grow on to form the hymenial layer for the following year. ' H. Hartig, Zerstlziuig.sa:scheiiiuuvr/.s.s. Zeifschrift, 1893) describes a plantation of Alnv^ incaiia in Tyrol, which was being killed out by this fungus (Fig. '2(V2). It is a common Britisli species. (Edit.) POLYPORUS. 435 side is concentrically marked, and has a stoue-hard coating which is generally more or less cracked ; several zones and layers of tubes will be found when the sporophore is cut in section. This fungus produces a white-rot in the wood, and is one of the most common and dangerous of wound-parasites. The wood attacked by the mycelium is at first dark in colour, then yellowish-white and soft. According to Hartig, a delicate mycelium fills up the elements and eats away the inner layers of the walls : then the middle lamellae are transformed into cellulose and al)Sorl)ed I)y it (Fig. 264). Polyporus fomentarius (L.) (Fomes fomcntcfrins (L.) Fr.) ^ (Britain and U.S. America). " Tinder-fungus." Sporopliores broad and shaped like reversed brackets or hoofs. Their upper side, at first brownish and velvety, becomes afterwards smooth, grey, and marked with broad concentric zones. The margin is rounded and uniformly grey. The pore-layer is smooth and greyish-brown. A longitudinal section shows a homogenous tinder-like mass, covered on its lower surface by layers or zones of pores. The tinder-fungus is parasitic on beech, elm, and mountain maple. It is particularly common in l)eech-fo rests, and was even more so at one time when the infected trees were allowed U) remain standing. The sporophores may be found on living stems, on remnants of trees broken by wind, and on felled trees. For some distance above and below the seat of the sporophore runs a furrow on the stem, marking a tract where the mycelium has penetrated to the cambium and killed it, so that growtli in thickness ceases (Fig. 2 60, a). The mycelium causes in the wood a white-rot of a light yellow colour. Where the wood is still firm, though diseased, it will be found to be divided into cubical portions by white tracts of mycelium which run both radially and vertically. A \ery characteristic feature of the destruction consists of l)road white leathery bands of mycelium, formed in a radial direction through the wood ; these are l)est seen on stems shattered by storm, or on wrought timlier.2 •Rostnip, TkhskriJ't pa Skovburg, 188.3. Tubeuf, " Mittlieilungen," A/foj. For,rtf-. u. Jar/d-Zeituug, 1887. A common British species. (Edit.) -Krull (Sckles. Ge.s. f. vaterland. Knit., 1893) distiugiiishes a gelatinous niyfeliuin and a cushion-mycelium. 436 EASIDIOMYCETES. Tinder, prepared from the soft central part of the thick sporophores, was at one time used, with the help of steel and flint, for procuring flame. It is very effective in stopping Fio. 2<5."i. -Scone in tlit; Bavarian forest near liisehulTs Jiccoli with seven sporophores of I'olt/iioras/on. ut. In the foreground, a li laruis. (V. Tubeuf pilot.) haemorrhage from cut blood-vessels, and is still used in surgery. The larger pieces can be manufactured into caps, gloves, vests. POLYPORUS. 43; and liose. The privilege of collecting the tinder-fungi was rented out and regarded as a source of forest-revenue, while the tinder-industry was formerly an important one in many districts, where sporophores were more frequent and larger than now. Measures against this fungus have already been considered in our (Jeueral Part (§ 12). Fig. 2<>u. — PohiporuK /omenlarins on living Beech, a, A fuiTOW extending above and below the insertion of the sporophore. 0, An injury produced by tearing of the wood in foiling, (v. Tubeiif phot.) Polyporus sulphureus (lUdl.) ^ (liritain and U.S. America). The sporophores are flat and soft, the upper side being bright orange-red and the lower sulphur-yellow. They last only for one year, lience are small ; they frequently occur in masses, one above another in tiers. After death they lose colour, become brittle, and are easily detached. According to De ' R. Hartig, Zersetzruiiisevscheiinoif/en. A very coininon species in IJritaiii. (Edit.) 438 BASIDIOMYCETES. POLYPORUS. 439 Seyiies,^ three other to l)usidiospores. Willow, poplar, oak, sweet chest- nut, alder, ash, hazel, pear, cherry, robinia, larch, silver fir, etc., are common hosts of this parasite. Wood infested by the mycelium darkens in colour, exhibiting a red- rot. Vessels and all clefts or spaces become filled with white felted masses of mycelium. The wood, in course of destruction, becomes richer in carbo-hydrates, and the walls of the wood-tibres shrink so that fis- sures with an upward right to left direction are formed, but do not reach the middle lamellae. Finally the wood becomes dry, l)rittle, and powdery. Polyporus borealis (Wahlenb.) Fi America). Sporophores annual, white. kinds of spores aie produced in addition 'i ' ^ t. Fio. 2. Pohn'orv^ xalplmrcus. The white niyceliuni forms concentric zones and radial lines on the cross-section of Oak. (.\fter R. Harti(j.) surface is shaggy when fresh, and no internal zones are exhibited. The shape is somewhat cushion or bracket-like, but very variable ; 1 De Seynes, Annul, de Sci. nat, Ser. V., Vol. i., 1SC4. -R. Hartig, Zersetzungierscheinungen, PI. X. 440 BASIDIOMYCETES. luiiny geiu'rally grow near each other. The pores have a torn margin and cystids are frequent between the basidia. The sporophores are common in spruce plantations, and are accompanied by a very characteristic wood-destruction. The wood, in the earlier stages, becomes brownish-yellow and inter- sected by radial and vertical canals filled with a white mycelium (Fig. 270). Gradually, however, it breaks up into small cube- Fir.. 270. l'l,l„,H„ LI. I,U,,UU^. D^slUlLtlUll Uf Spi-uce-w()i)d. The white iiiycehiiiii is present, dividing the dec.iycd wood into cubical pieees. (v. Tubeuf phot.) l''ii;. ■ITl. — l'oli/jiorus Ijorcaliti. Later stage of destruction. The Spruee-wood is broken up Into cubical pieces, and the mycelium has disapjieared. (v. Tubeuf phot.) like pieces, particularly evident when the wood is liroken (Fig. '271). Tlie cell-walls are dissolved from the eell-cavity out- wards, the lignitied wall being first converted into cellulose and disa[)pearing, finally the middle lamella. Polyporus dryadeus Fr.^ (P. 2y-^("i'(^oiffniarws Bull.) (IJritain and U.S. America). Sporophores, annual, large, shaped likt- tubers or hoofs, and generally situated towards the base of the ^R. Hartig, Zer-^etztiw/sersrheinimgen, PI. XN'II. A common Rriti.sli species. POLYPORUS. 441 Stems of oak-trees. At first they are soft, later hard and lirown with grooves on the upper side. The dark heart-wood of the oak exhibits white or yellowish longitudinal stripes of rotten wood converted into cellulose (Fig. 272). In the white portions \\ '■■] Flc. 272. — FoO/jiorus Uri/ail lih'. lliu iii.\ tcliniii Idiiiis loiiKitiui in the Oak-wood. (v. Tubeiif phot.) the destruction is more complete than in the yellow, where dis- solution of the lamellae has not as yet taken place (Fig. 273). A simultaneous destruction of the wood by F. drycuhus and P. iyniarius may occur (Fig. 274); in this case, the medullary 442 I'.ASIDIOMYCETES. rays appear snowy white at the place where the two forms of rot meet ; this is due to an accumulation of starch left after the cell-walls liave been almost completely dissolved. Polyporus (Poria) vaporarius (Pers.)^ (Britain and U.S. America). Tlie sporophores are white, and have a pungent odour ; they form crusts (never l)rackets) closely adherent to dead sul)strata, especially to l)eams and other timber in buildings, m Irnkm Fig. 273.— Polyporus dryadeus. Later stage of decay of Oak-wood. The darker places still consist of firm brown wood ; the white, however, are soft cellulose, (v. Tubeuf phot.) ^«-f" Fio. 27 i.— Polyporus dryadeus and Poly- porus igniarius. Destruction of Oak- wood under the combined agency of both fungi. The wood is yellowish and perforated ; the medullary rays are snowy-white, from the accumulation of unchanged starch, (v. Tubeuf phot.) where this fungus does great harm. They are also found, how- ever, on bark of living stems of spruce and fir. The destruction takes the form of a red-rot, the wood attacked becoming red- Itrown, cracked, and soft. The mycelium is found in stems and roots of trees ; in cracks in the wood and below the bark, and on the surface of timber in buildings, it forms fan-shaped strands of a permanent white colour. The mycelial strands of the "dry-rot fungus" {Mending lacrijiiunis) dilfer from it in being Very common in Britain on dead wood, less so on living trees. (Edit.) rOLYPORUS. 443 at first white but becoming grey, and in exhibiting an internal differentiation which those of F. vaporarius do not.^ The hyphae in the course of their growth do not seek out the pits, but grow straight through tlie walls and bring about dissolution of the middle lamella for some distance around. At the same time numerous short oblique fissures in the walls are produced vertically one over the other, especially in the elements Fig. ilo.—Polyporuii Kqii.aiuoKu.') oji Acer A'eriuixin. The three upper sporophorcs are borne on a separate piece of wood, from wliich a fourth has been tut off. (v. Tubeiif phot.) of the thick-walled autumn wood. (Compare with P. sistotrc- moiclcs, Fig. 280). The phenomena accompanying destruction of wood by this fungus are so characteristic that Conwentz'- could distinguish it quite clearly in tree-remains enclosed in an)l)er. Brefeld succeeded by artificial culture of the spores, in raising a mycelium on which basidia were formed, at first directly, afterwards from large sporophores. Polyporus squamosus (Huds.). (liritain and U.S. America.) ^ R. Hartig, Der erhte Hauiischtcamm, Berlin (Springer), ISS.l. -Conwentz, Monographie d. haltiischen Bi-rtistfiulKhmn . I.SJHI. iU BASIDIOMYCETES. Sporophores annual,, occuri'ing from spring to autumn ; at first tender and fleshy, later leathery or almost woody. In form they are short-stalked, flat, semi-circular or kidney-shaped, and attached by one edge ; they may also be stalked and circular or cup-shaped. Their upper surface is yellowish, with flat brown scales arranged in concentric lines. The hymenial layer is continued well on to the thick fleshy stalk of the sporophore ; it is yellow in colour, and consists of short angular pores. Fio. 270.— Po/-. ncs of living Ash. (v. Tubenf phot.) The spores are spindle-shaped and colourless. The fungus is especially common on living hazel, ash, species of maple, beech, mountain ash, horse-chesnut, elm, oak, willow, pear, lime, etc. The wood of the specimen in Fig. 275 exhibited extensive white-rot, the inner parts being completely converted into a soft white sjxiiigy mass of mycelium. Polyporus hispidus (Bull.).^ (Britain and U.S. America.) Sporophores annual, soft and spongy, with a rough brown upper 'A very common form on ash trees in liritain. (Edit.) POLYPOIIUS. *445 surface, and a smooth yellowish hymenial surface. They are large and fiat, the thickest part being at their insertion (Fig. 277). Several frequently occur on the same stem, especially if wounds or frost injuries are present. The spores are brown and roundish. Conidia are said, by Schroeter, to be formed on the upper surface of the sporophores. This species is a deadly enemy of fruit-trees, especially apple. In the vicinity of Munich the sporophores are common on ash. Schroeter gives elm and plane as hosts, and Prillieux Fig. 27". — Poli/pona hii'pidu.''. Longitudinal section through a living .stem of Ash, and a sporophore of P. hUpidus. The stem shows .symptoms of wood- destruction, in that it become8 brown and has short white longitudinal and radial stripes, (v. Tubeuf phot.) and Delacroix state the fungus to be very dangerous to the mulberry in France. It causes^ brown discoloration of the wood accompanied liy characteristic short white lines in both radial and vertical directions, so that the wood becomes marked out in squares. Polyporus (Poria) laevigatus Fr.^ Sporophores dark-brown ^ riillieux {Bulkt^ dt la i>or. mycolo'j. de Franct the destruction of the wood. -Mayr, Botan. Centralblatt, xix., 18S4. 189.3), gives details of 446 BASIDIOMYCETES. aud forming- crusts on tlie bark of birch. Spathulate cystidia occur between the basidia. Spores colourless, and acutely ovate in shape. This is parasitic on birch. The mycelium kills and permeates the wood-parenchyma which forms the greater mass of the later-formed parts of each year-ring, with the result that the various year-rings of the wood separate from each other as concentric hollow cylinders. The mycelium varies according as its pabulum consists of cells just killed, or of wood, or of elements in the last stages of decomposition ; in this latter case it suffers from want of food. In woody elements in contact with air, or those destroyed by Pol}i2wriis hchdinus, the mycelium is brown and forms vesicular tyloses similar to Af/aricus mrllcus. Polyporus betulinus Fr. (Ih-itain and U.S. America). The sporophores are annual, and emerge as spherical structures from the unin- jured bark, or from bore- holes of Beetles, or other wounds. When mature they are hoof-like or semi- circular and short-stalked : when dead they become soft and break off'. The upper side is light-brown in colour, the pore-layer is white. A section through the sporophore shows it to be white and homogeneous without zones. Lanceolate cystidia occur between the basidia. The spores are rod-like. The pore- layer and the upper brown layer are easily detached, and strips of the remaining tissue are sometimes utilized as razor-strops. This parasite frequents living birches, ultimately causing death. It is known to occur on both Betula verrucosa and B. puhcscejin in Britain, America, and Europe. Its parasitism and injurious results were first demonstrated by IJostrup.^ Mayr^ investigated Fig. "iTS. — Folyporus betuimiis oil Betula verrucosa. The sporophore was developed horizontally on a fallen stem ; it is here, however, set uj) vertically and pliotographed from the lower side. (v. Tubeuf phot.) iRostrup, •'Snvltesvainijer Augieb paa .Skovtracenio," TidsakriJ't pa SIcov- hurt,!, 1883. -Mayr, Botan. Centralblatt, xi.x., 18S4. POLYPORUS. 447 in greater detail the destruction brought about Ijy its mycelium. He found that it penetrates lignified cell-walls, entering the living elements and causing their death; it spreads most rapidly in the vertical direction through wood, bast, and rind, growing through parenchyma and sieve-tubes, and even boring its way into the sclerenchymatous stone-cells ; it absorbs the secondary thickening by dissolving out first the ligneous incrustation, next the cellulose, while the middle primary lamella remains behind untouched. Polyporus (Fomes) fulvus (Scop.) (Britain). Sporophores w^oody and very hard, at first hairy but later smooth, dark, and cracked ; in form they are tuberous or triangular. In- ternally they show no stratification. The fungus is very common on living plum where it causes undoubted injury ; it also occurs on hornbean and aspen. Polyporus fulvus var. Oleae Scop. In northern Italy may be frequently observed a peculiar splitting of the stems of olive trees into two or more portions ; the fissures occur generally on the lower parts of the tree, and may extend so deeply that the stem appears to stand on stilts or props. Hartig ^ ascribes this phenomenon to the presence in the olive stems of the mycelium of FohjiJorus fulvus causing rotten places which are cut out by the Italian cultivators ; the disease, how- ever, continuing to make progress, it may be necessary in course of time to cut so deeply into the stem, that tracts extending right through may be removed ; this takes place all the more rapidly if several diseased spots are being simultaneously operated on. The destruction of the olive-wood by this parasite is similar to that produced by P. igniarius on oak and other trees. The sporophores appear on rotten spots, but are gener- ally quickly removed by the cultivator. Infection takes place on wounds, hence it is advisable at once to apply tar after cutting out any decayed wood, and also to paint pruning-cuts or other exposed surfaces with tar. Neighbouring fruit-trees, liable to suffer from this same fungus, should be similarly treated, both for their own safety and that of the olive trees. Polyporus Fomes Hartigii Allescher'- {P. Ujaiarius var. 1 R. Hartig, "Die Spaltung w«destroyed by Polt/iiorun .lixtoti-'iiiouhf. The celbilose has been for the most part extnicted, and the waU« con- sist of lignin (wood -gum). Cracks occur in the dry secondary wall, while the wall (o, 0) remains intact. The spiral structure of the secondary wall causes cross- ing of the fissures in the walls of adjoining cells at tlie bordered pits, e, and at bore -holes, d, e ; where neither pits nor holes are. present the fissures are simple,/; (After H. Hartig.) 450 BASIDIOMYC'ETP> The two species are held by many autliors to he identical. It occurs chiefly on steins of beech, also on oak and bircli. In regard to its parasitism nothing further is known. Polyporus (Fomes) annosus Fr. (Trametes radiciperda Hartig^) (Uritoin and I'.S. America). 'I'lie sporophores vary much in form, according as they occur more above or more below ground on tree stems, or on timber in mines. The upper surface is brown and marked in zones, the margin l:>eing lighter. The section through the woody sporophore is white. The hy menial layer is also white. Spores ovoid and colourless, germinating easily in water. In artificial cultures, Brefeld states- that they produce only conidia. Fio. 'iSl. -I>o!i/j)o,-u.^ annosus Fr. (Trametes radkijv ala llartig). Stool of a forty-year Spruce, which lias been dead for two or three years. The sporophoi e is several years old. a, a, White open-pored layer forming over the dead basidial layer, h, h; at r a narrow strip of wood still remains firm, the remainder i.s completely destroyed and rotten. (After R. Hartig.) This species was first investigated in detail by 1(. Hartig,^ and is described by him as the most dangerous of all parasites in the conifer forest. It is most frequent on Conifers, e.//. pine, Weymouth pine, spruce, silver fir, Douglas fir, balsam fir, juniper, and Thvja ; it also occurs on various broad-leafed trees, e.g. beech ^ and hawthorn. 'R. Hartig, Zersetztinrj)ierKcheinwu/en, PI. I. -IV. III. Zeituchrift f. Forst-und Jagd-wesen, l.SS",>, p. XLii., 1890. IVichligti Krankheiten, PI. 4'2S. Botan. Centralhlat I . -Brefeld, Schimmelpihe, Heft 8, 1889. ' Rostrup, Afbildninri o;/ Beskrivthe af dv fari'njMt Siiyllesrampe, POLYPORUS. 451 The niyceliuni penetrates both bast and rind causing- a very acnte red-rot in the wood, so that death of the tree attacked rapidly follows. The disease makes its appearance on plants of all ages, and in forests of spruce or pine causes gaps which rapidly extend in a centrifugal direction. The roots and lower parts of the stem are generally the parts first attacked. On the roots, the parasite is easily distingui;>hed, even in the absence of sporophores, by the very delicate white mycelial i^-r-^ . •■.. ■ i membranes formed between the > bark-scales. Destruction of the wood becomes first evident by the appearance of vertical dark lilac- coloured stripes indicating the stage ' when the parenchyma cells are killed. At a later stage, the wood becomes brown, and shows isolated black spots with white margins (Fig. 282). These last consist of Jt;' coils of dark mycelium surrounded Llli.. ^-x-^ -. — - ~— - — — by wood from which the incrustin" v\v..-i^i.-Pob,r>orvii.innoxi»^. Destiuc- tiou of f?iiiuce-wood. Longitudinal sec- substance has been dissolved away, tion showing white (ceiiuiose) spots with , . 1 n 1 Ti T black (mycelium) centres, (v. Tubeuf leaving only cellulose, readily dis- phot.) tinguished by turning blue on treatment with chlor-zinc-iodine ; here too, the middle lamellae are ultimately dissolved out, so that the elements become isolated. A colourless mycelium may also be found in the other parts of the wood, both inside the elements, and extending in all directions through the cell-wall, leaving holes where it itself has disappeared. Dissolution of the lignifying substance pro- ceeds from the cell-cavity, the middle lamella remainiiig intact till the last. The resin of the decayed wood passes over into all healthy parts and flows from the bark of diseased stems as a resin-flux. The most effective method for combating the ravages of this parasite is isolation of infected areas. In one case which I investigated in Baden, several spots in the forest formed very evident starting points, and sporophores were everywhere present at the base of stems amongst the moss. Such spots should be enclosed by ditches with vertical sides, and deep 452 BASIDIOMYCETES. enough to cut through all roots, care being taken to leave no diseased stems or roots outside the circle ; after remaining open for a time, the ditch must be refilled with soil to prevent development of sporophores on the exposed roots. Diseased stems should l)e felled, and, along with all root-remains, burned on the spot, where there is no risk of forest fire ; failing this, they and their stumps should be deeply covered over with soil, to prevent development of sporophores. The following species of Polyporus have been obser^'ed on living trees, but details in regard to their parasitism and mode of destruction are still wanting : P. officinalis Fr. On larch, chiefly in Russia, but also in France and Switzerland. The sijorophores are white irregular masses, and .at one time were used in medicine. The mycelium forms bands in the wood similar to those of P. sulphureus. P. albus (Corda), according to Ludwig^ is a cause of a disease of C'onifens, which extends from the root upwards. (U.S. America.) P. spumeus (Sow.). On apple trees. (Britain and U.S. America.) P. fumosus (Pers.). On willow, ash, maple, and other broad-leaved trees. (Britain and U.S. America.) P. picipes Fr. On willow and other broad-leaved trees. (Britain and U.S. America.) P. (Fomes) cinnamomeus Frog. On cherry trees. (Britain.) P. radiatus (Sow.). On alder (^1. iHcaiut), birch, and beech. (Britain and U.S. America.) P. (Fomes) ribis (Fr.). On l)lack currant and gooseberry shrubs. (Britain and U.S. America.) P. (Polystictus) hirsufcus Fr. (Britain and U.S. America). On living hornbeam, alder, (jak, l)irch, and service. A variety, scruposus, is common and injurious on cherry. P. ulmarius Fr., is, according to Cavara,- parasitic on living elm near Pavia. (Britain and U.S. America.) P. (Fomes) nigricans. On birch. (Britain and U.S. America.) P. salicinus (Pers.). A dangerous eneniy of willow.'' (Britain and U.S. America.) Rostrup^ gives Corticium comedens as a wound-parasite of oak and alder. Hartig describes Fistulina hepatica, the liver-fungus, as causing a dark- brown colour in oak-wood. 1 Lntlwig, Lehrbuch d. nkdtren Kryptoijamen. -Cavara, Reime My col., 1891. ^'Tursky, Russian translation of R. Hartig's '' Lchrhiirh d. Baumkrankheiten." •*Rostrup, Fortmtte Undersoijdner, 1883. TRAMETES. 453 Trametes. Sporophores as in Puli/ponis, except that tlu' sul»,stance between the poie.s does not differ from that of the rest of the sporophore.-^ Trametes pini (IJrot.) Fr.- liing-scale of Pine. This is a dangerous forest parasite in Northern Germany ; also in liritain and U.S. America. On the pine the sporophores develop from branch-scars, and assume a bracket form. The fungus has also been observed on spruce in Bavaria and elsewhere, but in this case, the sporophores are more frequently found as a coating over the bark on the under side of a branch. Larch, silver fir, and the Douglas fir (in America), have also been mentioned as liosts. The sporophores are brown and woody, and continue to form annual hymenial zones for a number of years. The hymenial layer consists of pore-tubes lined with basidia, between wliidi thick-walled cystidia are formed. The spores are elliptical, and on germination penetrate into wounds or broken branches not protected by an outflow of resin. The older branches of pine and larch have a central heart- wood from which no resin is secreted, and these branches, when broken over, offer the neces- sary access to the germinating spores ; for this reason, infection takes place most frequently in old plantations. The mycelium spreads through branch and stem, particularly upwards and downwards in the same year-ring. In tliis way longitudinal stripes and peripheral zones are formed in the wood, giving rise to the popular name " ring-.scale." Single hyphae bore through the cell- walls, and a ferment secreted by then) dissolves the incrusting substance, so that walls affected show the re- actions for cellulose almost at once. A very characteristic feature is the appearance of isolated white spots or holes, indi- cating where the wood, after becoming cellulo.se, has been dissolved out entirely. The middle lamellae are dis.solved out first in attacks of this fungus, the tertiary lamellae remaining longest intact (Fig. 12). The dark centres of mycelium in.side ' The distinction between the genera Po/yponis and TrameOs is badly defined. A reinvestigation of the systematic relationships of the whole group of Polyjjoreae woidd in fact be advisable. -R. Hartig, Zi):ie/zuu;iser.schehningen, PI. V. and VI. ; Wichtuje Krankhdteuy PI. III. ; Lehrhurh d. Baumkrankhtiten, 1894 (English translation by Somerville). 454 BASIDIOMYCETES. white wood-spots, so characteristic of Polyporus annosi/s (Tram, radicipcrda), appear only rarely in this species. The destruction of spruce and fir goes on from pith to bark ; in iht' pine, liowever, it seems to be confined to the heart-wood, Fig. -IKi. TnnneicK pini on SpruL-i; (fifni cxc(lm). Sporophore on the stem beneath a snag-branch, (v. Tubetif phot.) Fig. 2S4. — y'/-(t„(W..s i,ini on .Spruce. Board showing the characteristic white cellulose-spot.s in the wood, (v. TuVjeuf phot.) and is prevented from entering the sap-wood by a firm zone permeated with resin. Remedial measures are the removal of all diseased stems TUAMETES. 455 at thinning; and the prevention of unnecessary injuries to living branches or stems. Trametes suaveolens (L), common on dead wiHow, is also reported as parasitic on living stems, (firitain and U.S. America.) AGARICINEAE. Agaricus. Sporophores umbvella-shapcd and th'sliy, and decaying soon after discharge of the spores. Hymenium on the under side of the uml)rella, and spread over a series of radiating gills or lamellae, easily divisible in a longitudinal direction. The genus is divided into sections and subgenera distinguished by the colour of the spores ; the Cojyrinarii are black-spored ; the spores of the Pratdli are dark purple, brownisli-purple, or dark brown; of the Bermini brown, yellowish-brown, or orange: of the Hi/pi>r/iv'/ii rosy or salmon-coloured : of the Lrucospori white. Agaricus (Armillaria) melleus VahU dbitain and U.S. .America.) 'i'lie iioncy-fungu.s or " liallimasch." The sporophores are present in nundjers towards the close of summer on tree- stools of all kinds, and on the bark of dead or living Conifers ; also on timber, and even on earth. The fleshy stalk is somewhat thickened towards its base, and towards the upper part bears the membranous yellowish annnlus (Fig. 286). Tlie cap sur- mounting the stalk is honey-coloured or brownish with dark scales. The spores are white and bestrew adjacent ol)jects with a mealy dust. The sporophores are edible. The connection Iietween the sporophores and the rhi/omorjih- strands was proved by Hartig. These rhizomorphs are very common and vary nuich in form ; they occur as round brown strands running through the earth from root to root of attacked trees; inside hollow stems and in wooden water-pipes, they retain their rounded form, but under the bark of trees they become dark brown flattened bands (Fig. 288). They are not uncommon on timber : in mines they may be frecjuently seen hanging from the woodwork as tangled clump.s, with PI. XI R. Hartig, Wirhtvjt Krankheilen, PI. I. ami II. ; Zer>ielzuiieard (Saxifrcu/a sarmeiitosa). The rhizoniorphs live as saprophytes and have been long known to emit phosphorescent light. Sporophores are developed directly on them, and if one sows the spores, a delicate hyphal tissue is produced, which, under suitable conditions, passes gradually over into the rhizo- morph-strand. Brefeld succeeded in raising rhizomorphs from spores in artificial nutritive media. Fig. -iSj.— .-if/ai'/ctts }iuUcu.^ near a licech-stool. (v. Tuliuuf phut.) The Af/aricus-inyce\i\im forms fan-shaped snowy- white firm membranous expansions under the bark of newly killed or still living trees. They are quite distinct from the much more delicate mycelial expansions of Poli/porus annosus, and offer a particularly easy means of distinguishing between the two species. Another indication of Agaricus is the great outflow of resin from the bark at the base of the stem and from roots, whereby hard clumps of earth are formed round the roots. The passage of the rhizomorphs into the white membranous mycelium is easily observed. The AGARICUS. 457 rhizomorphs distribute the fungus in the earth and other dead substrata, as well as bore into the bark of healthy Conifers. This parasite attacks not only the indigenous Conifers (spruce, silver fir, pine, larch, and juniper),^ but also the introduced forms — Weymouth pine, Douglas fir, Pinus riglda, Abies Pichfa, Picea sitchensis, various Ciqrressineae, etc. It also seems to attack broad-leafed trees, at least as a wound parasite.- In regard to the interesting structure of the rhizomorphs, and the characteristic mode of wood-destruction caused by Fig. 2St5. — Atjai'icuis wilbun. Sijnrophote developed from a rhizomorpli-stniud ; the other branch be.ti-s arrested sporophores. (After R. Hartig.) Fig. 2S". — Ar/uricus melUvx. Section through a lamella. (/, The hyphae forming the subsfcmce of the lamella are mucli branched, and send twigs outwards which end in club-shaped basidia, « ; on many of these are developed sterigmata with apices swollen into spores, I, ; c, isolated thread- like arrested basidia projecting above the hymenial layer. (After R. Hartig.) this fungus, I give directly the account by Hartig in his "Lehrbuch."^ "The pathological symptoms can only be ex- plained in the light of the peculiar organization of the mycelial growth that lives in the cortical tissues. The apex of the rhizomorphs consists of delicate p.seudoparenchyma, which, elongating liy the division and growth of the cells, produces delicate hyphae on the inside at a certain distance from the ij found it on juniper in the pine-forests near Eberswalde. (Autli.) - The mycelium does not seem capable of penetrating uninjured hroad-leaveil trees, but R. Unrtig {Forsl/.-iia(m-irU>: Zei(.schrift, 1894, p. 428) mentions attack and death of cut roots of healthy oaks. •'R. Hartig, Lehrhuch il. Baumkrankhfilen, 1889. The translation given here is from Prof. Somervilles English edition of Hartig's te.\t-l>ook, p. 210. (Edit.) 458 BASIDIOxMYCETES. point, wlierel)}' a felted tissue, called the luedidla, is produced in the interior. The outer parts of the pseudoparenchyma, on the other hand, coalesce to form the so-called rind, which when young gives off numerous delicate hyphae, and these, taking advantage of tlie medullary rays, penetrate the wood, and especially tlic resin-(Uicts, should such be present. In the wood the growth is upwards. This filamentous mycelium, which pro- gresses much more rapidly in the interior of the wood than the rliizduiorphs which grow in the cortex, completely destroys 3. — Ajjaricun meUeus. Rhizomorphs in the form of dark anastomosing ids, developed between the bark and wood of a treu. (v. Tubouf phot.) the parenchyma that exists in the neighbourhood of the resin- ducts, and to all appearance this is accompanied by a partial conversion of the cell-contents and the cell-walls into turpentine. The turpentine sinks down under its own weight, and in the collar, where the cortex is withered, having been killed by rhizomorphs, it streams outward, pouring partly in between the wood and the cortex, and partly into the surrounding soil at places where the cortex has ruptured owing to drying. On this account the disease was formerly called ' Kesiu-tlux ' or AGARICUS. 459 * Kesin-glut.' In the upper parts of the stem, where the cainbiuni and cortex are still sound, the turpentine also flows laterally, 1)y means of the ducts of the medullary rays, from the injured canals towards the cambium and cortex. In the latter this accumulation induces the formation of large resin-blisters. When, during the .summer, the cambium is forming a new ring, the plethora of resin has the effect of causing the production of numerous resin- canals, which are usually large and abnormally constructed, and these impart to the wood-ring formed during the year of sick- ness a very striking and characteristic appearance. " The mycelium gradually spreads from the cells of the medullary rays and from the resin-ducts into the vascular elements of the wood, where it produces a form of decay which may be termed a variety of white-rot. During the progress of the decomposition from the surface of the stem inwards a certain stage is reached, which is highly favourable to the development of the mycelium. While previously it was simply filiform and furnished with numerous lateral hyphae, it now develops large l)ladder-like swellings, and at the same time the hyphae change into a kind of large-meshed parenchyma, which, like the tyloses in the vessels of many dicotyledonous trees, completely tills up the lumina of the tracheides. On account of the mycelium assuming a brown colour when in this condition, it makes the portion of diseased wood which it infests appear, to the naked eye, like a black line. As tliis kind of mycelium soon dies off and is dissolved, being replaced l»y a delicate filamentous mycelium, it seldom happens that the zone which it occupies exceeds the breadth of three to four tracheids. The walls of the elements of the wood afterwards display a cellulose reaction, and speedily dissolve from the lumen outwards. "On account of the trees drying up, after the rhizomor])hs have spread from the point of infection on the roots into the stem, and again from the stem into the hitherto sound roots, decomposition of the stem usually ceases before the mycelium has advanced from the alburnum into the duramen. It is only in the stool and roots that decay rapidly spreads tlnoughout the whole of the wood." Methods for exterminating this parasite are unknown, ln-yoiid removal of diseased plants and collection of sporopliores. It would certainly be advisable not to plant young conifers on 460 BASIDIOMYCETES. cleared forest-laiul where the fmiuus sporophures are numerous on dead stools or roots. Agaricus (Pholiota) adiposus Fr.^ (Ihitain and U.S. America). This is a conspicuous brii^ht yellow or honey-yellow toadstool, with a glistening slimy cap which, as well as the stalk, is beset with concentric darker scales (Fig. 289). The scales and delicate annulus become indistinct or disappear on old sporophores or after much rain. The stalk is thick, Heshy, and stiff', and while growing so changes its direction as to keep the cap always in a horizontal position. The pileus or cap, at Fig. •2S9.—A(/aricM adiijosas. A, A mature and a very young sporophore grown in the forest ; the other sporophores were raised on Fir-wood in a cellar. The latter have longer thinner stalks, and a basal swelling beset with white down. B, Mature and germinating spores, (v. Tubeuf del.) first globose, opens out cone-shaped or flat with a diameter of about 5 cm. Remains of the velum adhere to the margin. The underside of the cap is at first yellow, later mouse-grey. The lamellae are of three sizes, the largest extending from margin to stalk. From the lamellae arise the basidia, with four sterigmata each giving off a single spore. The spores fall at maturity, and cover neighbouring objects with a brown dust. They are oval with a length of 7-10// and a breadth of ~)-()ju. The sporophores spring up rapidly in large num1)ers on •v. Tubeuf, " Eine neue Krankheit d. Wcisstanuo." Zii/srhr.f. Forxt it. Jai/ii- wesen, 1890. AGARICUS. 461 living stems of silver tir, beech, etc., and on felled wood.' In the forest, on newly erected piles of firewood, the yellow stools may frequently be found in every stage of development growing from the cut billets, while they arel especially numerous on the rotting useless timber left lying. ' -VIn cellars or other moist Fia. 290.— .-(f/oiicu.? adi/WKUx. Destruc- tion of Kir-wood. The deeply-corroded cross-fissures contain white mycelium ; the remainder of the wood is vellow. (v. Tubeuf phot.) tion of Kir-wood. Later st.ige. The corroded fissures no longer contain my- celium. (V. Tubeuf phot.) chambers, the sporophores may be abundantly produced till Christmas, but out-of-doors, August is the time of fructification. The mycelium forms felted masses under the bark or in cracks of the wood, and thence the sporophores arise as little pale- yellow buttons, which gradually unfold and become differentiated into cap and stalk. While quite young, they show tlie darker 1 Previous to the publication of v. Tubeuf s investigation the fungu.s li;ul only been observed on living beech and felled wood. 462 BASIDIOMYCETES. scales arranged regulnrly in concentric lines. The stools break out from living stems through cracks in the bark or from wounds, r.//. those made by wood-peckers. The fir-wood, normally white, assumes, when diseased, a yellow or honey-colour, more or less like the sporophore, while here and there, parts may become light brown. The hyphae grow in all direc- tions, but especially as white strands up and down the year-rings, while others in horizontal and vertical direction break up the wood into irregular patches (Fig. 290). * In the final stages of destruction the wood will be found A laminated into its separate year-rings %. and very much broken up into irregular \ pieces (Fig. 291). I' , The sporophores of this Afjaricus are not uncommon protruding from l)ark- cankers caused by Aecidium clafinvm, and its mycelium assists in the destruc- tion of the stem. W." '^■H^'i FlO. 292. — Agaricus adiposiis and Polyporum Hdrtigii. Destruc- tion of Fir- wood. The boundary of the regions affected by the two fungi is formed by a verj- dark line of demarkatiou. To the right the destruction is that produced by Pobjporov.s Hartigii, to the left by AgarirvK n.dipoxv^. (v. Tubeuf phot.) Agaricus (Pholiota) squarrosus (INIiill.). On living and deail stems of broad-leaved trees. (Britain.) Ag. (Ph.) destruens (Brond.). On living and dead steins of poplar. (Britain.) Ag. (Ph.) aurivellus (Batsch.). On living and dead stems of broad-leaved trees. (Britain.) " FUNGI IMPEEFECTI." The fungi placed here have life-histories which as yet Iiave not been completely investigated, most of them being known only in the form of pycnidia or conidia. The number of species was at one time much larger, but it is gradually being re- duced as the forms are proved to be stages in the life of some species of definite systematic position in the other groups already considered. The group may be divided into the provisional sub-groups, the Sphacropsidcae, Mclanconieae, and Hyphomycctes. FUNGI IMPERFECTI. 463 I. .SPHAER0P.S1DEAE. Conidia abjointed I'lom conidiophores contained in darl- colourcd pycnidia somewhat spherical in form. The various species are provisionally arranged in genera according to the colour of the conidia and the number of cells contained-' in them. The families here included are the Sphacrioidmi', Kcc- trioidcae, Leptost romacmc , and Excipulaceac. I. FAM. SPHAERIOIDEAE. HVAI.OSI'UIIAK. Phyllosticta. Fungi witli colourless spores, and produring sharply defined spots on living leaves. They occur on all kinds of woody plants, but as a rule the injury caused is too slight to be called a disease. From the long list given by Saccardu (Vols, iii., ix., and x. ) the following have been selected : Phyllosticta persicae Sacc. This produces on leaves of peach brownish- \('llow spots, frequently marked by concentric zones. The name " shot-hole fungus " has sometimes been applied to this and other allied forms, because the leaves become more or less perforated by the withered spots falling out. The pycnidia on reaching maturity rupture the lower epidermis of the leaf in a star-like manner. Briosi and Cavara do not regard this parasite as very harmful, because leaves attacked by it remain alive without serious prejudice to their function. Ph. pirina Sacc. has been observed injurious to pear-trees at Geisenheim (( rermany). Ph. prunicola Sacc. is the cause of spotting of leaves of apple, plum, clierry, and apricot. (U.S. America.)^ Ph. cytisi Desm. On leaves of C'l/tisus Lfdinnuna in Britain and Europe. Ph. acericola Cook et Ellis. On various species of maple {Acer dasj/caipum, etc.). It is described by Galloway - ^The chief authorities for the occurrence of the "Fungi imperfecti " in Britain and North America are Massee (Bntiah Funrjtist Flora, 189")), Farlo\\- and Seymour {Host-Index for U.S. America, 1891), and Saccardo (SyUoi Fuck. This is probably the cause of the gradual blackening of the leaves, yet it does not appear to lose its saprophytic nature. Frank also gives Phoma bctae Fr. as one cause of the heart- rot of the sugar beet (comp. Phoma). It will thus be seen that the cause of the rotting of beet- root, sugar beet, and mangold is still very obscure.^ Ph. galeopsidis Saec. On leaves of (laleopsis Tetrahit. (Britain.) Ph. atriplicis Desni. On leaves of Chenopodium and Atnple.vm Europe and Britain. Ph. chenopodii Saec. has been found injuriou.s to spinach in America. Ph. podophylli (Curtis). In leaves of PodopJnjllum peltatum in America. Ph. primulicola Desm. On withering leaves of Priimda. (Britain.) Ph. ruscicola Dur. et Mont. On leaves of species of Ruscus. (Britain.) Depazea. A provisional genus including species of which the spores or conidia are unknown, so that the forms included in it will probably be found to be related to various groups. They live in many cases on living leaves, causing discoloration. Some of them are : Depazea acetosae Op. On Rmnex Acetosa. D. impatientis Kirchn. On Impatiens Noli-tangerc. D. geicola (Fries). On (Jeum tirhciimm. Phoma. Conidia unicellular and colourless. Pycnidia black and em- bedded, but having a distinct pore. The species produce spots with ill-defined margins. Phoma abietina Hartig- {Fasicoccum ahidinum Prill, et Delac). This parasite is a frequent cause of death to the silver fir. The branches become brown, yet retain their needles, hence when they occur isolated amongst neighbouring green branches they are at once conspicuous. On close e.xamination of the dead or dying brandies, areas of shrunk or con- ^ According to Karlson (Petrowsk. Akad. f. Laudwirth-schajl, 1890) and Hell- fiegel (Zeitsrh. dei Vereiii f. Jiiibenzuckerimlu.'itrie d. deiiiach. Reiches, 1890) insects take no part in it. 2 Hartig, Lthrhuch d. Bmimkrankheilen, Ed. ii. (Englisii Edition by ^^'. Somerville). Mer, E., Journal de Botanique, 1893. 2G 466 FUNGI IMPERFECTI. stricted tissue will be found extending quite round the twig (Fig. 293). At these places the bark and cambium have been killed, whereas the higher portions of the twig have continued to increase in thickness. Numerous small black pycnidia break out on the bark of diseased places and give off small unicellular spindle-shaped conidia, which convey infection to new hosts in August or September. Killed branches die and dry up without casting their needles.^ Ph. pithya Sacc. causes a disease similar to the preceding on the Douglas fir {Pscmlotsuga Douglasii). The pycnidia of the fungus are found on dead constricted parts of twigs, and they, as well as other symptoms of the disease, closely resemble those of Phoma abietina. Tiostrup" defined and de- scribed it as Ph. intliya Sacc, Magnus also re- cords it on branches of Pinus sylvestris in Berlin botanic garden. Other species of Phoma frequent other conifers and broad- Fi. 90, and Jknt.sr/u' laudw. Pr. No. 89, 1893. Kriiger, ZcM-ich. f. Pflan-enkranUidtcn, iv., 1894, p. 195. '•^Described and figvu-ed l)y Halsted in Bulletin 91, N. J. Aii Brassica oleracea. A. dianthi (A.S.). On Diantlms. (Britain.) A. pallor Berk. On Ruhus Iddem. (Britain.) A. viciae Trail. On Via'ti. sepiam, etc. (Britain.) A. malvicola Sacc. On Jfalva si/lvestn's. (Britain.) A. graminicola Sacc. On various grasses. (Britain.) A. scabiosae Eabli. On Knautia arvensis. A. nicotianae Pass. On Nicotiana TaJxtccnm. A. digitalis Fuck. On DifjitaliK pnrjuired. A. fragariae Sacc. has been found injurious to tlie strawb Tiiited .States. A. aspidistrae given (d'ardeners Chronicle, xvii., l^tiJ.j) a Aspidistra in Britain. ^ Boltshauser-Amrisweil, Zeitxchrijt f. Pflanztnhankhdliu, parasite earint;' tliese same specitic names. Leptostroma. Pycnidia oblong, black, and flattened. Conidia ov(jid or oblong, unicellular, and whitish. Leptostroma punctiforme Wallr. Found on the leaves of Salic, Iiosa, IJi'.ii/s, Evpliorhia, etc. L. caricinum Fr. frequents leaves of Carcx and Eriophonim in Europe and North America. The parasitism of other species is uncertain, Labrella and Discosia are genera whose species have not as yet pro- duced diseases of any serious economic importance. Phragmosporae. Entomosporium. Entomosporium maculatum (D.U.) Lev.^ This fungus, under the name of leaf-blight of pear and quince, is the cause of considerable loss in the cultivation of these crops. Defoliation takes place early in the season and young seedlings are forced to form a new set of leaves, whereby their reserves of food are exhausted. If this be repeated several times the plants become exhausted and are killed off in winter. Stocks already l)udded seem to remain immune if not already diseased. The leaves are first attacked, but later the succulent growing apex of the twigs may also succumb. The parasite hibernates on the bark in small depressions containing the pycnidia ; thence it spreads in early spring, so that pustules appear on the young leaves before they are fully developed. Spraying with Bordeaux mixture, or solution of copper acetate 'Galloway and South worth {Rej)ort for 1888 of Section of Ve'jetabk Pathology, Dept. of Agriculture, U.S. America) give a historical account of the fungus an. pim Allesch.). In Xor- way almost all the plantations of Austrian black pine {Pinufi Laricio) from five to thirty years old have become diseased and died out. Similar ravages have also been observed in Germany. Brunchorst ascribes this to a parasitic fungus whose mycelium may be found in all parts of diseased twigs and needles, and whose pycnidia are formed on the killed remains. The disease begins in young first-year twigs, the mycelium growing in the cortex, pith, and wood. The needles are attacked in summer, become brown from the base upwards, and tlie pycnidia make their appearance under the scale-leaves. Brunchorst ^ describes the fungus as follows : Pycnidia par- tially embedded in the tissues of the host-plant ; the smaller ones being simple, the larger divided by complete or partial partitions. The inner wall as well as the partitions of the pycnidium are closely beset with straight basidia, from the apices of which stylospores with two to five septa are abjointed. Paraphyses are never present. The perithecia are black, oblong or rounded, slightly grooved, and 1-2 mm. in diameter; they dehisce by one or more irregular pores in the wall. The spores are very minute (30 — 40 = oai), tapering, and rounded at each end. Schwarz considers Bruncliorstia as a conidial form of Ccnan- guim ahidis already described (p. 251). It may be here mentioned that drying-up of pine-twigs may be due to heating by the sun in frosty weatlier, or to frost itself; 2 these are, however, quite distinct from the disea.se just described. ^Fairchikl (Journal of Myeofor/t/, Vol. vii.) gives results of treatment with various fungicides ou several varieties of pear and quince. (Edit.) ^"Ueber eine neue Krankheit d. Schwarzfohre." Bergeus Museum, 1889. ^R. Hartig, " Vertrocknen u. Erfrieren d. Kiefernzweige," Forstlichnaturv:iss. Zeitschrifl, 1892 and 1895. 2h 482 FUNGI IMI'ERFECTI. 4. FAM. EXCIPULACEAE. The parasitic nature uf the speeies ol' this family has not as yet been investigated to any extent. II. MELANCONIEAE. True pycnidia are not formed, but the conidia are deveh)ped in clusters or aggregations covered over at first by the epi- dermis of the host-plant, which is ultimately ruptured. TlYALOSl'Ot^AE. Gloeosporium. Conidial clusters colourless or grey, never black ; they rup- ture the overlying epidermis and give off unicellular conidia, one from each conidiophore. Gloeosporium fructigenum Berk.^ (Britain and U.S. America). Apple Eot or liipe-rot. This is a very serious disease for American cultivators. It not only attacks apple, but also the grape, pears, peaches, and egg-plants." On the apple it appears first as brown spots which become more conspicuous as the fruit enlarges. The spots on first sight look like decay, but they are quite firm and soon bear pustules of a white or pinkish colour turning to black. The attacked part of the apple has an intensely bitter taste, and should be carefully removed before eating the fruit. On grapes the fungus produces tiny raised pustules, which on the white varieties are situated on spots with a purple centre and a brown margin ; the pustules when mature give off flesh-coloured conidia. The grapes gradually shrivel up, but do not become black as in the case of the black-rot, nor do they assume a bitter taste as the apples do. The apple bitter-rot makes rapid progress amongst stored fruit, especially before it has been sorted out. Care should therefore be taken that diseased apples are removed as soon us possible. The spraying of trees bearing young fruit with copper car- ' Soutlnvoilh, JouDial of Mycoloipj, vi., ]>. \(\\. -Halsted, Bulletin of fht Torrty Club, IS9.S, p. 10!>. Massee, Gardener's Chronicle, Vol. xiv. , 1S93. GLOEOSPORIUM. 483 bonate or potassium sulphide solutions has good effects on the yield of the orchards. In vineyards under treatment for black- lot or mildew, there is little chance of the ripe-rot fungus appearing. It is probable that the species known as (U. phomoides Sacc. on tomato, Gl. pijjeratum E. et E. on peppers {Capsicum (innuum), and Gl. mclangeac E. et Hals, on the egg-plant, are identical with Gl. fructigeiium. At least they very much resemble each other, even on their widely differing substrata, and cross-infections have been carried out. Gl. venetum Speg. {Gl nccator Ell. et Ev.) Anthracnose of raspberry and blackberry.^ This disease appears on both canes and leaves. On the young shoots it produces small reddish- purple spots during early summer ; as the season advances the spots run together into irregular l)lotches of more or less greyish colour with a dark purple margin. The ripening IVuit remains small and shrivels up. Leaves may also bear spots, but they more frequently remain smaller and have an unhealthy look. The conidia are at first enveloped in a thin covering, which becomes gelatinous when wet, so that they escape. The mycelium is believed to perennate in stems or decayed remains, and so to carry the parasite from season to season. Owing to the delicate nature of rasplierry foliage, fungicides nuist be used with great care. Dilute Bordeaux mixture is said to be safe and beneficial. The burning of diseased canes should certainly be carried out each autunni. Gl. ribis (Lib.). This attacks currant bushes throughout Europe and America in much the same way as Gl. vrnctum. The leaves wither and fall, so that the fruit-crop suffer-s. (Britain.) Gl. amygdalinum I'.rizi.- This has recently been described as destructive to almond cultivation in Italy. The mycelium inhabits twigs and fruits, and gives off tufts of conidioi)hores bearing conidia ; as a result, wounds are produced in the epidermis and stunting of the host-tissues takes place. Gl. rosae Hals, is described as injurious to rose-culture in America. It may be identical with some of the species of Gloeosporium already mentioned as frequenting liosaceae. ^ U.S. Amerira Dept. of Agriculture, Report for 1889, contains a good account. -Brizi, Zeitsch. f. Pflanzenkrankheiten, 1896, p. 65, 484 FUNGI IMPKRFECTI. Gl. ampelophagum (I'ass.)^ Black-rot of the vine. This disease is very injurious and has a wide distribution in Europe. It is known under many names sucli as " Pock, Brand, Host, Jausch, Brussone, and Nebbia nera," though probably these names include several distinct diseases. The identity of this Glocofiporiuvi is somewhat uncertain, and it may really be identical with Fhovia ampdinum (p. 467). Riithay ascribes the black rot to Sphacdoma (Fhoma) ampdinttin, while Thltnien regards Gloeosjmrmm as the cause. Briosi and Cavara consider the two species of fungi as distinct. Thiimen says that the patches of Gloeospormm are for a consideralile time disc-like and of a light-grey rose colour; those of Fhoma, on the other hand, are always depressed and brown. Bathay, however, de- scribes the spots of Fhoma as at first dark brown, and later ashy grey with a brown margin. The spots appear on green parts of the vines during April and May. Those on the leaves frequently fall out, leaving holes. On the grapes the spots are smaller and produce a brown coloration extending deep into the fruit. The conidia are small, hyaline, oval, and unicellular ; they are abjointed from very short conidiophores arranged in little clusters. The conidial patches rupture the host-epidermis, and the conidia are liberated. Thiimen suggests that the soil of vineyards should lie kept well cleaned, and that the stake mode of culture be used in pre- ference to an overhead trellis ; he also recommends the wasliing of all parts of suspected vines during winter with 10 to 15 per cent, solution of sulphate of iron. This treatment is said to have been very beneficial in keepijig many vineyards quite healthy and free from fungi. Gl. nervisequium.^ This parasite occurs on species of F/atanns in Europe and America. Brown spots appear on the leaves, especially on the veins ; tliese as they extend cause sudden withering and fall of the leaves. Pustules containing a stroma develop on the spots, and unicellular, ovoid, hyaline conidia are abjointed from club-shaped conidiophores. ^Thiimen, Die Pocken an Wein n. OhM. 188a; Die B(d-ampfii»r/ d. Pihl-ravh- hfiitoi, 1886; De Bary, Annaleii d. Oenologie, iv.; Viala, Lea maladies de la Vigne ; Briosi e Cavara, Funghi paraait., iii. ; E.' Eathay, "Z)er Black-Rot,'" 1891. ^ U.S. America Department of Vegetahle Pathology, Report for 1888, gives a general account of this disease. GLOEOSPORIUM. 485 Several fimgi of very ne.ar relationship, if not actually identical, occur on Platanus} All cause considerable disfiguration of the foliage, so that a systematic destruction of all young diseased branches is strongly recommended. Gl. cingulatum Atks.- This is the cause of Anthracnose on Privet {Ligastrum vidgarc) in the United States. The following is Atkinson's diagnosis: "Affected areas light brown, either oblong on one side of the stem or completely girding it. Acer- vuli 100 to 150 in diameter, rupturing the epidermis, in age black from the dark stroma lying in the base or extending irregularly up the sides, frequently forming a pseudopycnidium. pjasidia numerous, crowded, simple, hyaline, or when very old perhaps faintly fuliginous. Spores oblong, or elliptical, straight or little curved, usually pointed at the base. From jiustules on the stem they measure 10-20 by 5-7; in artificial cultures they are frequently much larger, but when crowded in the media, or when the nutrient sultstances are nearly exhausted, they may be considerably smaller. ( )n stems of Ligastrum vulyarc. " Tiiis is quite distinct from Crloeosporium lujustriiium Sacc." Many species of Glocosporium frequent Ijroad-leaved trees and cause more or less injury to the foliage. Gl. rhododendri Br. et Cav, attacks the leaves of outdoor cultivatetl rhododendrons in autumn, or indoor species in winter. Large yellow spots marked with concentric zones are formed, and bear the pycnidia ; finally the leaves dry up and fall off. Gl. violae W. et Br. attacks violets in lUitain and U.S. America. Gl. vanillae C"ke. et ^lass. (Caluspora ranilho' Massee."^) This causes a dangerous disease on VaiiiUd ijlanifvlia and other Orchideae in Mauritius and other parts of the tropics. Death is brought about by the Gloeosjiorium (Hainsca) form of the fungus, the higher reproductive organs only appearing when the leaves are killed. Other species are known, but their economic importance is not great. ^ V. Tavel, Botun. Zi.itiuni, 1SS6; Leelerc dii Saldon, Renin qtn. de. Bodtnirpte, 1892. -Atkinson, "A Xew Anthracnose of tlie Privet,"' Cornell Unir. Ar/rir. Exper. Station Bulletin, No. 49, LS92. •^Massee, Keio Bulletin, ls9-2, p. 111. 486 FUNGI IMPERFECTI. Myxosporium. Conidia ovoid, hyaline, and alijointed from rod-shaped basidia situated in cavities of the cortical tissues of arboreous plants ; a true pyenidium is not formed, and the reproductive mycelium is only covered over by the epidermal layers of the host. Myxosporium devastans Rostr.^ is said to attack and kill young twigs of Bituht verrucosa. The conidial patches are developed in the killed rind, and give off unicellular colourless conidia. M. carneum Lil). is parasitic on twigs of beech. M. laneola Sacc. et Rouni. causes deatli of oak-twigs. Tlie other known species have as yet been observed only as saprophytes. Colletotrichum. Conidial patches surrounded by setae ; characters very like Glocosporiuiii. Colletotrichum Lindemuthianum- (Sacc. et Magn.).-' This disease, first ol^ser^•ed by Lindeinuth in 1875, has assumed great importance as a disease of the kidney bean {Phascolus vulgaris) both in Europe and America. Young pods are most frequently attacked, but neither stems nor leaves are exempt. The pods show brown depressed spots with a distinct margin. The unicellular and oblong conidia are given off from short conidiophores developed on the spots. Germination takes place at once, the germ-tube forming an adhesion-disc on the host- epidermis, and from this a hypha penetrates into the tissues to develop into a brown mycelium. Frank obtained brown spots and mycelium on young beans twenty-four hours after infection. C. Lagenarium (Pass.) {0. oligochadam Cav.), This parasite is very injurious to seedlings of water melon {Cucumis citrullus), melon (C. Mdo), and the gourd {Cucurhita Lagenaria). Leaves and fruits may be attacked, but it is the cotyledons and stems of the seedling ])lants which most frequently fall a prey. Spots iRostrup, Thlssh-ifl f. Skorracsni, 1893. -For the relationship of this with the following species, as well as their synouomy, see Halsted in Bn/le/hi of Torrey Botanical Cluh, 1893, p. 246. Description, treatment, and bibliography by Beach, " Bean-spot disease," Genera JS'. Y. Exper. Station BnUctin, No. 48. " COLLETOTRICHUM. 487 api)ear on the leaves, and depressions on the stem, sometimes extending so far round that the whole shoot dries up. The conidial patches are very much the same on the different hosts, and consist of short conidiophores from which oval, unicellular, hyaline conidia are abjointed. C. lycopersici Cliei^r. is lUe cause of a spot-disease on the fruit of tomato in the United States. C. spinaciae Ell. et. Hals, causes a destrueti\e disease on cultivated spinach. C. malvarum Br. et Casp. (C. aWiacac Southw.^) produces a disease of cultivated hollyhock. It is most injurious to the seedling plants, and has caused great loss in America and Sweden. The fungus may attack any organ, and produces spots which enlarge so rapidly that death of the host may rc'^nlt. C. gossypii Southw.- Anthracnose of Cotton. This disease, although it may be found on stems and leaves, is most frequent and most conspicuous on the fruits or " bolls " of the cotton-plant. The first signs are tiny depressed spots of a reddish-brown colour, and as these enlarge they cause blackening of neigh- bouring tissue. When the spores are developed the spots become dirty grey, or perhaps jjinkish if the spores are present in large numbers. Fruit attacked in this way does not mature well, and the yield of cotton is greatly prejudiced. Atkinson found the cotyledons ea.sy to infect with the disease. The spores are oblong and tapering, with a .shallow constriction in the middle ; they are borne either on short colourless basidia or on long, olive-coloured, septate setae, both kinds of conidin- phore being produced in acervuli or patches. C. adustum Ell. is the cau.se of a leaf-sjiot on orange in Floiidii. Fig. iii&.—ColUlotrichum Linde- vthianvni on pod of Kidnej' e:iii. Enlarged pustule and midia. ^ .Southw orth, "A New Hollyhock Disease," Journal of Myroloiiy, vi., IsHU. -Southworth, Jovrnal of Mycoloijy, vi., 1890, p. 100. Atkinson, Alabama Afiri<'. Exper. Station Bulletin, No. 41, 1892. 488 FUNGI IMPERFECTI. Faded spots appear on the leaA'es, becoming later greyish brown dotted over with minute bhick points, the couidial patches.^ C. ampelinum C'av. causes little dry spots on the leaves of vine, fre- quently in such numbers that the whole leaf dries up. C. kentiae Hals, attacks palm -seed lings so that tlieir leaves do not unfold. C. cyclameneae Hals, occurs on Cyclamen. Scoleco-Allantosporae. Cylindrospormm. The white and shiniiio- couidial cushions are embedded in the host- plants. The conidia are filamentous, frequently somewhat twisted. Cylindrospormm Tubeufianum Alles- cher. This attacks the livino- oreen fruit of the bird-cherry, and causes the forma- tion of brown spots from which pustules break out ; the premature dropping of diseased fruits follows. In the locality where I observed this disease, numerous trees were attacked and most of the frnit on each was badly diseased. The my- celium spreads through epicarp and mesocarp, but does not penetrate into the endocarp, so that the development of the embryo is not directly interfered with. The conidia originate in pycnidial cavities without any- special peridium ; their shape is given in the annexed diagnosis.^ The pycnidial cavities arise under the epidermis which is afterwards ruptured and witli the cells underlying it becomes brown and dead. ^This note is taken from Underwood, Journal of Mycolony, vri.,l)ut no mention is made of it in the later paper by Webber and Swingle (" Diseases of Citrous Fruits in Florida," U.S.A. Dapt. of Agriniltiire Bvilefin, 8, 1896). (Edit.) -Allescher gives the following diagnosis of this species: Pv-sfiilis j»-iiimm Fig. 299. — Ci/lind>mporium Tubeufianum on fruits of Prunus Padus. The unshaded parts re- present parts still green and living, :iUlinnL;-lil.eai-iim- )nistiiles piistul.s -. ll.at tlic r,\U arc- killed and brown. :) natural size. (v. Tubeuf del.)" coiiri .ris, 1 />/ Padi, quos necaf. 1/1/(1/ is. , hi/ull '/"" ■11/, H /,///(! //(I /is sC/l/i/hn,)illllSI is /;/ /-oi/lhi, i//lh//s. hil,,i-l,i-,i//,//,ilis. siihf, (,///>/, //il„'/s : ,;mi/liis jilif,rnlih/is, /■///■/■u/is /; / /!,.v- 40-UU = 2-.V. II(il>. Ill frucdhiis i/nmaturis Pviui'i CYLINDEOSPORIUM. 489 As yet the disease has been observed in quantity only in tlie neisjhbourhood of Oberammergau (Upper Bavaria). C. padi Karst. Leaf-blight of cherry and plum. This dis- ease is most destructive in the nursery, causing premature defoliation of young trees ; it may also cause severe injury to fruit-bearing trees. The leaves become spotted and perforated by holes caused by the falling out of withered spots. Spraying with dilute Bordeaux mixture early in the season is said to have good effects.-' Ji Fi(i. 300.— A fruit from Fig. 2euf del.) C. filipendulae Tluim. (jceur.s on leaves of Spiraea Filipendula. C. ficariae Uerk. On leaves of Ranunculus Ficaria. (Britain.) C. viridis E. et E., and C. minus E. et E. On leaves of Fra.rinns rin'tfin in the United Statei^. C. cercosporoides E. et £. On living leave.s df tulip-tree. C. saccharinum E. et E. On living leavt-s of Aicr sacdiarinum in the United States. Cryptosporium. Conidial cushions ."^liaiicd like ]iy('iii(lia. Conidia rod-like or spindle-shaped. Cryptosporium leptostromiforme Kiiiin.-' This fungus forms rows of black .sLioniala on tliu .stems of lupines; in the stromata are formed pycnidia-like cavities with several neck-like openings, and in them conidia are given ott' from conidiophores. The conidia are rods with rounded ends 7-8'5/x long and about 2yu broad ; they emerge from the necks of the cavities as long tendril-like chains, and may be continuously given off 'Fail-child (Journal of Mycology, vii., p. 24it) gives result.s of remedial treatment. -J. Kiihn, Btrirhh- d. lamlirlrlh. lust., Halle, 18S0. Fischer, '' Cryplotporiiou hptoHtromiforme." Breslau, 1S93. 490 FUNGI IMPERFECTI. througliout tlie whole summer. Fisclier has proved experi- mentally that the conidia germinate easily in water, that the germ-tubes penetrate into living lupines, and produce a mycelium which spreads through stems and leaves to develop stromata on all the organs of the plant. The formation of both pycnidia and conidia goes on throughout the autumn and following spring on dead plants, the fungus being capable of living as a saprophyte and of hibernating. The disease may occur with great severity. Fischer describes cases where more than the half of the plants in a field were attacked and died before flowering or soon after. There is thus a loss not only in lupine seed, but also in the good effects which the crop has as a " green manure." Fischer gives the following measures for keeping this pest in check : " Where the fungus has obtained a footing, lupines should not be planted till at least tlie year after next, and then only as a catch-crop on stubble : it would be still safer to keep lupines off the land till the third or fourth year. After lupines as a catch-crop, they may safely be sown again in spring as a seed crop, after the lapse of a clear year. No lupines should be cultivated near diseased fields. Instead of ploughing-in a catch-crop of lupines directly, it should be dried and used as litter for cattle, because the excrement has been found to kill the fungus ; the lupines after lying over winter in the manure- heap could then be used as manure in spring. Similarly when the lupines have been grown for seed, they should be closely mowed down so that little stubble is left ; the straw may then be used fen- litter." This fungus has not as yet been observed on plants other than lupines. DlOVMUSroRAE. Didymosporium. Conidia brown, oval or spindle-shaped, bicellular, and not produced in chains. Didymosporium salicinum \'uill. Vuillemin reports this as very destructive to the Osier cultivation in Bourgogne. Marsonia. Conidia transparent, two-celled, and not produced in chains. The species live on leaves. MARSOMA. 491 Marsonia juglandis (Lib.) produces on leaves of Jiujlans little greyish yellow spot.s witli brown margins ; thereon stromata are formed, wliich rupture the epidermis and liberate the large sickle- shaped conidia. (Britain.) M. populi (Lib.). On leaves of species of Popidits in Europe and Britain. M. potentillae (Desm.). On species of Poteutilla. (Britain.) M. campanulae Bres. et All. On Campanula latifol/a. The fi)ll()\vin,i( are North American species: M. toxicodendri (Kll. ct Mart.). On Rhus To.ricodendron. M. quercus Peck. On (Jaercus ilicifolia. PnR.\GMOSPORAE. Coryneum. The conidial patches are black and disc-like, and ru})ture the host-epidermis. The conidia are oblong or spindle-shaped, yellowish, and pluriseptate ; they are abjointed from short conidiophures. Coryneum Beyerinkii Oud.^ This is stated by Beyerink to be the cause of a " gum-Hux " of cherry and allied species of Rosaceae. It is the conidial form of Ascosjyora (see p. 211). C. camelliae i\Iass.- occurs on living Camellia leaves at Kew. (Britain.) Pestalozzia. Conidia spindle-shaped, with two or more brown mcdiau cells and hyaline terminal cells, the one at the free end carrying several ciliate processes. Pestalozzia Hartigii Tub.^ The external effects of this disease have been long known, although the fungus causing it has only been recently detected. It attacks young plants of various trees and shrubs. The symptoms are yellow discoloration of the foliage, and constriction of the stem just above the level of the soil, followed by death of the whole plant. At the constriction of the stem the rind gradually dries up, whereas neighbouring portions continue to grow in thickness till finally the bark is ruptured (Fig. :\0'2). In the living part of the ^ Oudemans, Jiedwitjia, 18S3. -Cooke, GrtvUlea, xx., p. 8, 1891. •'v. Tubeuf, Beitrtifie zur Kenntniss d. Bmnnkrankhtiten, 1888; a.nd For s/lirh - noftirwisH. Z<-ifschrif't, 1S9-2. Pig. Z01.—Pcstalozzia Hariigii. Young Spruce Fio. 303.- showing constriction jiist over the surface of the diophores on soil. (After v. TuVjeuf.) I'ESTALOZZIA. 493 rind of young plants of spruce and silver fir, I succeeded in finding near the place of constriction, a delicate mycelial stroma enclosing some cavities (pseudopycnidia). Conidia were formed inside these cavities and emerged to the exterior. They belong to the genus Festalozzia, and have two brown median cells, a trans- parent stalk-cell to which the long stalk is attached, and a transparent terminal cell carrying two or three transparent thread- like appendages (Fig. 303). (Termination results in the emission of a strong germ-tube from one of the three lower cells. If at any time the conidia dry up, the two clear transparent cells m,M Ftf). 30-\.—I''-.<,■■<( on Cliaiuotci/pari.^ MukUsU. ,\t the pl.iccs marked X cainbiuin and rind have been killed, so that growth in thickness no lonffcr takes place ; the hiffher parts, however, have continued to thicken, but are gradually dying, (v. Tubeuf phot.) collapse and the appendages easily fall off, so that on material of this kind the conidia are only two-celled and brown. The mycelium after cultivation in nutritive gelatine soon produces conidia. This fungus was found by Kostrup on beech, producing much the same effects as just described. On this host it has been found very destructive in young naturally regenerated forest, the loss in Bavaria and Wurtemburg within very recent years having been estimated at 30 per cent. It also occurs on ash, sycamore, and other trees. P. funerea Desm. (TU-itain and U.S. America). The spores of 494 FUNGI IMPEKFECTI. this fungus were found by ]>oelim^ on diseased cypress trees, and although investigations are not yet complete, it is believed that this Fcstalozzia is the cause of a well-known disease on cypress. The symptoms on Chamaccyparis Mcnziesii are local constriction of stems and branches, and death of portions beyond. The rind and cambium of constricted places are killed, the hark becomes split, and the wood dries up. P. funerea is a well-known sapro- phyte on twigs and needles of Cupressus, Junipcrus, and other Conifers ; its occurrence as a parasite has been suggested several times. P. gongrogena Temme" is said to cause the canker of willow. Tn diseased willows Temme found an intercellular and an intracellular mycelium with pycnidia and conidia of Fcstalozzia, but other pycnidia of unknown affinity were also present. P. insidiens Zab. On bark of Ulmus americana. (U.S. America.) P. phoenicis Grev. causes a disease on indoor cultivated palms. The following are some of the more important forms frequenting living leaves : p. Guepini Desm.^ (U.S. America). The conidia of this species are found on large spots with dark margins on living leaves of Camellia japonica, Magnolia, Citrus, Bhododenclroii, and other plants. Spore-patches appear on the epidermis, and give off conidia embedded in a mucilaginous slime. The conidia have three dark median and two hyaline terminal cells, the distal one bearing the characteristic appendages. The leaves are permeated with mycelium and fall prematurely. P. inquinans (.". et Hark. On Eucalyptus in California. P. stictica B. et C. On Flatanus occidentalis and Tilia in United States. P. concentrica B. et Br. On leaves of Crataegus, Pi/nis, Custanea, and Quercxis in North America. P. suffocata E. et E., and P. discosioides E. et E. On cnltivated and wild I'ose shrubs in America. Pestalozzina. Conidia similar to those of Fcsf(duzzia, but all the cells hyaline. ^ Zeitschri/t f. Forst. u. Jagd-wtsen, 1894, p. 63. '-Thiel's lanchvirth. Jahrlmch, 1887; and Bei: d. deiitsrh. botan. Ges., 1890. '■'Annal. des Science nalur., Ser. ii., Vol. xiii., 1840; Briosi et Cavara, Fnnglii parasiL, vi. PESTALOZZINA. 495 Pestalozzina Soraueriana Sacc.^ occurs on foxtail grass {Alopccuri's jn'tid/ish^). The conidial tufts develop on spots which appear on the gradually withering leaves. The bristle-appendages on the terminal cell of the conidia are lateral, only one being terminal. This disease was first observed by Weinzierl at Menna, Fig. Z05.—S(pto{iloeum Hartigianum on Actr cnmpeslre. The dead twigs exhibit black points and lines— the pycnidia of the parasite, (v. Tubeuf jihot.) and has not as yet been Ibund out of that neighbourhood ; it attacks the pure-culture seed-beds only. Septogloeum. Like (/((voxporimii, exceiit that it lias pluricellular conidia. Septogloeum Hartigianum Sacc.- Twigs of the common maple {Acer campcstre) are subject to a disease, which exhibits ^.Sorauer, Zeifichrift f. PflanzenhrankheUen, 1894, p. 213. -R. Haitig, Forstlirh-natiiriL-m. Zeitsrhrift, 1892, p. 289. 496 FUNGI IMPERrECTI. itself in the drying-up of young twigs before their buds open in spring. The older branches, however, assume their normal foliage. Examination of diseased twigs reveals the mycelium of a parasitic fungus living both inside and between the cells of rind and wood. Conidial patches break through the host's epidermis about May as long greyish-green lines. The conidia are hyaline, three-celled, and cylindrical with rounded ends ; the conidiophores are short thick rods. In May and June the spores are capable of infecting new hosts, and germinate in a few hours. Infection of twigs takes place in summer, and the mycelium spreads through the first-year shoots, without, however, giving any external indication of its presence till the following spring, when the twigs dry up as already described. S. ulmi (Fr.) may be a form of PhiiUachora vlmi. The myceliam lives in parenchymatous cells, and causes the formation of brownish-yellow spots on leaves of the elm. The conidial patches form tiny points on the lower surface of the leaf: they consist of pycnidia-like structures without a peridium, arising from a stroma developed under the epidermis. The conidia are spindle-shaped and pluricellular. S. mori (Lev.) is stated by Briosi and Cavara to produce yellow spots with brown margins on the leaves of Morus alba and M. nigra. Death and premature defoliation of the host then take place. The conidial patches develop under the epidermis, and rupture it as the conidiophores emerge ; they have no real peridium, hence the fungus cannot belong to the group Phleospora, as Saccardo supposed. The conidia are long, cylindrical or fila- mentous, and pluricellular. Amongst the more important North American species are : S. profusum (E. et E.). On living leaves of Corylm aincricana. S. fraxini Hark. On Fraxiuus Orrgana. S. apocyni Peck. On Ajjoryn'w cannahinum. III. HYPHOMYC'ETES. Conidia produced neither in pycnidia as in Sphaeropsideae, nor from a special stroma as in Melanconideae, but free on conidiophores given oh' from the mycelium. HYPHOMYCETES. 497 The group is subdivided into the families of the Mucedineae, Dematieae, Stilhcae, and Tuhcrcularicac} I. FAM. MUCEDINEAE. 1. Sect. Amerosporae. 1. Subsect. Micronemeae. Oospora. Conidia, transparent or only slightly coloured, globose or ovoid, non-sej)tate, and produced in regular chains from simple short conidiophores ; they thus resemble the genus Torula in the Danatiau. Oospora scabies Thaxt.'^ is said to cause the well-known scab or scurf on beet and potato. This consists in portions of the surface of the subterranean tubers swelling out as rough brown excrescences. Other authors ascribe this disease to bacteria. Microstroma. Conidia unicellular, transparent, oval, and shortly stalked. Microstroma album (Desm.). This, although common on living leaves of several species of Quercus, is not a serious disease. The conidial patches on the under side of the leaves are white and very thin. (Britain.) M. juglandis (Bereng.) frequents the leaves of Jv.glans regia and ./. riiima in Europe and Xorth America. Monilia. Conidia oval or spindle-shaped, and produced in chains from branched conidiophores. Monilia fructigena Pers. (Britain and U.S. America.) This is the cause of certain widespread diseases — the brown-rot of cherry and plum, the peach-rot, and a rot on apples and pears. It has been the subject of many papers since Thiimen first described it in 1879.^ All parts of the host are attacked, and 'This is the arrangement followed by Massee, "British Finujus Flora," Vol. III.; there the characters of the various sub-divisions may be obtained. (Edit.) ^Thaxter, Connecticut Aijric. Exper. Station, Report, 1890. •'Amongst the more important descriptions are: Thiimen, Funcji Pomicola. 1879; Smith (Worth. G.), Gardener's Chronicle, 1885, p. 52; Arthur, Xew York Aqric. Exper. Station, iv., 1885. 2l 498 FUXGI IMPERFECTI. exhibit reddish or yellow spots ; therein the mycelium spreads rapidly and gives off tufts of conidiophores which rupture the epidermis. The conidiophores are septate, branched, and give off chains of unicellular oval conidia. Meanwhile the affected fruit becomes rotten and gradually shrivels up, it remains, however, hanging on the tree throughout the winter. During Fig. 30C\—MoHilia fructigena more or less concentric lines, attack, (v. Tubeuf del.) A, Apple showing the grey conidial patches as S, Young Peach, slnivelled up in consequence of next spring, when the fruit is again moist, further conidia are given off'. Infection takes place by wounds or even through the epidermis of young leaves and blossoms. The conidia have Fio. 307. — Monilui fructigena. Branched conidiophore with chains of conidia. ", Branched hypha of MonUia in the tissue of an Apple, (v. Tubeuf del.) been found to retain their vitality for two years. Smith ^ found that twigs were also affected by the disease, so that a gummy degeneration took place in the soft bast and cambium. As remedial measures, the gathering of all diseased fruit left hanging over winter is strongly recommended. This, as well as other diseased parts, should be l)urned as soon as possible. ' Smith (Ervvin), Journal of Mycology, vii., p. 36. MOXILIA. 499 Washing of stems with a sohition of iron sulphate in spring before the buds unfold is suggested, also spraying of young foliage with dilute Bordeaux mixture. Oidium. Mycelium epiphytic on living plants. Conidia unicellular mid barrel-shaped, produced in chains on erect conidiophores. Many have already been proved to be conidial forms of Erysipheae. Oidium erysiphoides Fr. frequents living leaves of hop, clover, cucumber, etc., and is probably the conidia of species of J^i-tjsiphc on these hosts. (Britain and U.S. America.) 0. Tuckeri Berk. On leaves and berries of the vine {see Uncinuhi, p. 176). 0. leucogonium Desm. On roses; probably the conidial form of Splia.i roflirrii pannosa (see p. 172). 0. farinosum Cooke. On living leaves of apple-trees. (Britain.) 0. chrysanthemi IJabh. On leaves of cultivated chrysan- themum. (Britain.) 0. aceris Babach. On leaves of Acer Pseudoplataaus. It is probably the conidial stage of Uncimda hicornis. (Britain.) 0. mespilinum Thiim. On leaves of medlar. (Britain.) 0. destruens Peek. On Amdanchicr canadensis and Prunns SI ri'fiiid m America. 0. tabaci Thiim. On leaves of tobacco. 0. monilioides Link, probably the conidial stage of Erysiphe (jraminis, occurs on living grasses over the whole world (see p. 175). 2. Sub-sect. Miicronemeae. Botrytis. Mycelium grey. Conidia more or less spherical, and pro- duced in aggregations on the ends of branched conidiophores. jVIany of the species are saprophytes, others are parasitic on plants or insects, and others form sclerotia ; the latter have already been considered under Sclerotinia (see p. 267). The following are known to be parasitic on plants : Botrytis cinerea Pers. This enemy of many plants has already been noticed as Sclerotinia Fuckcliana ; so also B. Dov.glasii Tubeuf. 500 FUNGI IMPERFECTl. B. galanthina 8acc. occurs on the bulbs of Galantluis nivalis in Britain. B. parasitica Cav. produces sclerotia and conidia on Tulipci GcsncrirtiKi in Italy (Sdcrotium tulipac). B. vulgaris Fr.^ This is a very common species, and includes several well-marked varieties. It is said to be parasitic on cultivated lettuce causing a " leaf- rot." B. fascicularis Sacc, is reputed to be the cause of a " fruit- mould " on the egg-plant {Solanum Mdongena) in the United States. A Botrytis is figured by Atkinson- as frequent on diseased carnation-plants. Ovularia. Conidiophores simple except for tooth-like projections near the apex on which the conidia are developed. Conidia uni- cellular, colourless, solitary, rarely in chains. " Closely allied to Ramularia, but distinguished l)y the one- celled conidia " (Massee). Ovularia pulchella (Ces.). Briosi and Cavara distinguish this as a disease of Lulium italicum in Italy. The leaves become black-spotted and permeated with an intercellular mycelium, from which arise the erect, branched, septate conidiophores. The more vigorous conidial patches have a delicate rose colour. 0. necans Pass, produces large spots on the foliage of quince and medlar, so that the leaves gradually wither and dry up. Conidia appear as a white powder on the dead remains. This fungus is recorded from both Italy and France. The following are British species occurring on leaves ; several of them, however, are placed by Saccardo under Ramularia : Ovularia lychnicola (Cke.) Mass. On Lychnis diurna. O. senecionis (Sacc). On Seneeio vidgaris. O. lactea (Desiii.). On species of Viola. O. armoraciae (Fuck.). On cultivated horse-radisli. It is reported as somewhat destrtictive in the United States. O. interstitialis (B. et Br.). On under surface of leaves of prinn'o.se, forming yellow spots in the angles of the veins. O. primulana Thlini. On leaves of Primula. O. cochleariae (Cke.). On Cochlearia officinalis. MVeluner on species of Botrytis, Zeitschrift f. FJlanzenJcranlcheiten, 1894. -Atkinson, "Carnation Diseases," at Amer. Carnation Society, 1893. OVULARIA. 501 O. alnicola (Cke.). On A/nus glutinosa. O. scelerata (Cke.). On Itammculus sceleratus. O. rosea (Fuck.) produces irregular brown spots on the leaves of vaiidus s])ecies of willow. O. asperifolii (Saec). On Symphytum officinfdis. O. veronicae (Fuck.). On spots on leaves of Veronica Chamaedrtjs, etc. O. lamii (Fuck.). (Jn Lamium. O. syringae (Berk.). On Syringa. O. sphaeroidea Sacc. causes spots on leaves of Lotus. O. carneola Sacc. On spots on leaves of Scrophularia nodosa. O. bistortae (Fuck.). On spots on leaves of Polygonum Bistorts. O. obliqua (Cke.). On leaves of Rumec. •>. Sect. Didyjiosporae. Didymaria. Conidia two-celled, colourless, and produced singly at the extremity of simple erect conidiophores. Didymaria prunicola Cav. Cavara states that this causes rai.st'd roundish spots on the upper surface of leaves of plum ; finally the leaves gradually dry up and fall oft'. Slender two- celled conidiophores are produced, and give off each a two-celled obovoid conidium. D. Ungeri Cord. On living leaves of Ranunculus repens. (Britain.) D. astragali (Ell. et Hoi.). Found on leaves of Astragalus canadensis. D. spissa Hark. On lea\o.s of Solidago occident'dis ; both species in North America. Bostrichonema. Conidiophores erect, spirally twisted, unbranched, and non- septate. Conidia elliptic or oblong, two-celled, and hyaline. Bostrichonema alpestre Ces. On living leaves of Polygonum virlparii III and 1'. lli^tvrla. (Britain.) B. modestum (T.. et 15. Wliite). On leaves of Alrlirmilla (ilpiua. (Ihilain.) ?,. SkCT. rHRAG.MiiSI'Ull.\E. Ramularia. Conidiophores emerging in tufts from the stomata ; they give off a terminal conidium, then bend over and produce a lateral conidium, and so on they branch in a sympodial manner, pro- 502 FUNGI IMPERFECTI. diiciiig conidia at the end of each branch. Conidia septate oval or cylindrical, and light-coloured. " The parasitic habit, simple or sparingly branched hyphae, denticulate and bearing the septate conidia at the tips, charac- terize the genus, which differs from Orvlaria only in the septate conidia " (Massee). Ramularia cinarae Sacc. is said by Prillieux^ to have caused great destruction in the cultivation of artichokes. The leaves became spotted and died, so that no flower-heads were produced. The following are British species : Ramularia hellebori Fuck. On leaves of Hellehorus foetidus and H. viridis. R. epilobii (Schn.). On leaves of Epilohium. R. ulmariae Cooke. On leaves of Spiraea Ulmaria. (U.S. America.) R. geranii Fuck. On under surface of leaves of various species of Geranium. R. lampsanae (Desni.). On Lampsana and Hyiwchoeris. R. pruinosa Sj^eg. On Senecio jacobea. R. plantaginis El. et Mart. On leaves of Plantago major. (U.S. Am.) R. variabilis Fuck. On leaves of Digitalis undVerbascum. (U.S. America.) R. calcea Ces. On leaves of Glechoma hederacea. R. urticae CVs. On leaves of species of Urtica. (U.S. America.) R. pratensis Sacc. On Rume.r Acetosa. R. rufibasis (B. et Br.). On Myrica Gale. Some of the more important North American species are : Ramularia rufomaculans Peck. On the buckwheat {Fagopyrum escvlen- tum), it has })roved a somewhat injurious fungus. R. albomaculata Peck. On leaves of Carya americana. R. viburni E. et E. On leaves of Viburmim Lentago. R. celtidis E. et K. On leaves Celtis occidentalis. R. desmodii Cooke. On leaves of various species of Desmodium. R. brunnea Peck. On living Tussilago farfara. R. areola Atks.- This causes spots on the foliage of cotton. " Spots amphigenous, pale at first, becoming darker in age ; irregular in shape, limited by the veins of the leaf, conidia in profusion giving a frosted appearance to the spots. Conidio- phores fasciculate, in small clusters distributed over the spots. Conidia oblong, usually abruptly pointed at the ends " (Atkinson). R. Goeldiana Sacc. is said to kill leaves and twigs of Coffca arahica in lirazil. i"Maladie d. Artichauts," Bullet hi di la xor. vii/colo;/. dc Fravre. 1S!)2. 2 Atkinson, Botanical Gazette, xv., 1890, p. 166. PIRICULARIA. 5oa Piricularia. Conidia grey, pluricellular, somewhat pear-shaped, and pro- duced from the apex of simple erect conidiophores. Piricularia oryzae Br. et Cav. This species is described by Briosi and Cavara as causing a disease of rice in Northern Italy. The plants become spotted and reddish-brown in summer, finally withering. The conidiophores arise on the spots on the lower surface of the leaf, and bear light-grey three-celled Fig. 30S. — Mastiriosporium album, (v. Tubeuf del.) conidia. Diseased plants may be found bearing this fungus only, frequently however it is in company with other fungi. Cercosporella. Conidia hyaline, similar to those of Ccrcospora, and produced from simple or branched hyaline conidiophores. Cercosporella persica Sacc. is parasitic on living leaves of peach. In America it has been known since 1890, and receives the name of " frosty mildew." It causes yellow spots on the lower surface of the leaf. 0. pastinacae Karst. occurs on living leaves of cultivated parsnip. 504 FUNGI IMPKRFECTI. Mastigosporium. Conidia hyaline and four-celled, frequently bristled. Mastigosporium album Riess. produces oblong dark spots with light margins on leaves of living grass. The conidia are produced on the margins of the spots (Fig. 308). Fusoma. Similar to Fusarium, but the mycelium is loose and not aggregated into a tuft. Conidia spindle-shaped and septate. Fig. 300. — Fusoma parasiticum. Dis- eased Pine-seedlings, with, a, root killed ; li, hypocotyl killed ; c, first leaves and plunmle killed. (After R. Hartig.) Fig. 310. — Epidermis of a Pine-seedling with a stoma. Some hyphae of Fusoma have produced partial dissolution of cell- walls. (After R. Hartig.) Fio. 311.— Fusoma parasiticum. Coni- dia— immature, mature, and germinat- ing. (After R. Hartig.) Fusoma parasiticum Tub.^ is the cause of a disease of seed- lings, particularly those of Conifers. The first symptoms are dark patches on the seedlings, followed by their collapse. There- ' E, Hartig, For.stlich-naturwis.s. ZeitschH/t, 1S98, p. 4:«. r J ^.1- FUSOMA. 505 after in moist weather or umlcr artificial cultivation, a light-grey mycelium appears bearing numerous slightly curved, tapering, pluriseptate conidia (Fig. 311). In Bavaria and Baden this parasite has caused great loss in the seed-beds of conifers. F. inaequale Hover, (^n living leaves of Tara.mevm officinale. Septocylindrium. Conidia cylindrical, hyaline or pale-coloured, with two or more septa, and produced in chains. Septocylindrium aromaticum 8acc. occurs on living Acorus C(iJa)ni/.s, killing heaves and even plants. The mycelium grows intercellularly and produces spots. The conidiophores emerge in tufts from stomata included in the spots, and give off long thread-like, pluriseptate, hyaline conidia. 2. FAM. DEMATIEAE. 1. Skct. Amkik.sporae. 1. Suhsect. Micronemeae. Many of the genera of this subsection contain species found on the living leaves of plants, but none of them are yet of economic importance. 2. Suhsei't. Macronemeae. Hormodendron. ^Mycelium grey, epiphytic, and creeping. Conidiophores erect, branched, and septate. Conidia spherical or ovoid, unicellular, and ]ir(i(lurO(l in cliains. Hormodendron hordei I'.r.^ This produces a characteristic spotting of the haulms and leaves of barley, accompanied by a stunting of the whole plant and poor development of the ears. This is not a true parasite, but when it appears in quantity it has considerable effect, attacking whole fields and causing great injury. The spots and conidia are found also on wild Hordcnm mvrinum on the margins of roads and fields. ' Brulme in Zopf's lieitrage z. Physio/, it. MorphoK nitd. Ornanixmoi, iv., 1894. 506 FUNUI IMPERFKCTL 2. Sfx't. Didymosporae. 1. Si(h.-t('ct. Microitcmeae. Dicoccum. Coiiidia oblong, two-celled, and arising from short simi)le conidiophores. ]\Iycelium subcuticular. Dicoccum (Marsonia) rosae (Bon.) causes brown spots on living leaves of roses, and a premature leaf-cast takes place. Little mycelial stromata develop between the epidermal cells and their cuticle, and give off two-celled hyaline conidia. D. uniseptatum B. et Br. forms dark patches on twigs of C/citi(ifiH cifdilxi. (Britain.) D. lathyrinum Ell. et Gall. On living leaves of Latliyrus ocliivlcucns in America. Cycloconium. ]\Iycelium subcuticular. Conidia one- to three-celled. Cycloconium oleaginum Cast.^ When this fungus is present, the leaves of the olive show roundish light-brown spots with dark margins, then becoming discolonred, they roll up and drop off. The mycelium grows in the walls of the epidermal cells, branching dichotomously ; branches of the hyphae break out through the cuticle as sac-like cells, which become the conidio- phores. The conidia consist of one to three cells. Kruch states that Cercospora cladosporioidcs is often present along with this disease of the olive, and may take some part in causing it. Peglion states that this or an allied species occurs on leaves of Qucrcus Ilex. 2. Suhsect. Macronemeae. Passalora. Conidia oblong or spindle-shaped, two-celled, and borne on tlie apex of greenish pluriseptate conidiophores, arising from an olive-green mycelium. Passalora bacilligera M. et Fr. occurs on living leaves of Alnvs (jiiifiiiosd. (Britain.) P. microsperma Fuck. This frequently covers the whole lower surface of the leaves of Alnvs incana with little tufts of ' Knich, Bulh'iin soc. hot. it.a(., 1892. IJoyer, J\'erherr/tes siir leu maladies de VOUvier, Montpellier, 1892. PASSALORA. 507 brown septate conidiophores, bearing long, two-celled, obovate conidia. Fusicladium. Mycelium greenish and sparingly septate. Conidiophores in tufts, short, erect, and bearing terminal conidia. Conidia ovoid or clavate, and one or two-celled. The species are conidial forms of Venturia, and have already been considered. Some of the better-known forms are : Fusicladium dendriticum Wallr. (Britain and U.S. America). This attacks the leaves, shoots, and fruits of the apple (see p. 218). Fifi. Z12.— Ventiirin (Fusicladium) dendrilicuvi forming brown wixits on an apple ; those still In the earlier stages have a radiate margin and bear conidia. The enlarged section shows two rows of large-celled parenchyma of the apple, covered bv a stroma of pseudopareuchyma bearing conidiophores and conidiu. (V. Tubeuf del.) F. pirinum (Lib.) (U.S. America). This is a cause of " spotting " on leaves and fruits of the pear, also of species of Crataegus and Amclanchier. The conidial patches are brownish in colour. Peglion states that this parasite forms sclerotia in tlie bark of twigs. It is probably a conidial form of Venturia ditricJia rar. 'pl/ri. F. cerasi (IJabh.) attacks the cherry orchards with such virulence that tlie crop may be rendered quite unsaleable. F. eriobotryae Cav.^ Cavara states that this attacks the ' Cavaia, Rivista di Patologia Ver/efale, 1892. 508 FUNGI IMPEKFECTI. leaves of Mespilus {Eriohotrya) japoiiica causinlant leniaiiis, but it is also common on living- leaves of many plants. The first suggestion that this form might occur as a parasite came from Haberlandt ^ and Frank." It possesses a dirty-grey, thick, septate mycelium, which may be colourless when young or growing inside a substratum ; it applies itself closely to the surface of plants and even pene- trates through the storaata or cell-walls into the tissues. The conidiophores are erect, otherwise variable in form ; they give oft' conidia from the apex or from lateral processes. The conidia are oval and contain a variable number of cells. Organs of plants attacked show grey spots, and withered parts if they are still alive. The following are some of the papers describing Cladosporium herbarum as, in certain circumstances, a parasite. Prillieux and Delacroix,^ on apple-trees and raspberry-bushes ; Cavara,"* on raspberry, cycads, agave, and other plants : Sorauer,^ on peas. Lopriore^ describes this fungus as the cause of a "black" disease on ears of wheat ; the results of infection were however somewhat variable. Pdtzema Bos reports it as producing disease, and in some cases death, in fields of oats. Kosmahl and Nobbe ^ found that seedlings of Pinus rigida blackened and died suddenly in the beginning of May, apparently from the attacks of this fungus. Janczewski " states that this Cladofiporiiim is a conidial form of Sphaerella Tidasnei, a new species of Ascomycete estal)lislied liy him.^ CI. elegans I'enz. This causes on the orange a disease or "scab," which has been injurious both in Southern Europe and the Southern States of America.^ It attacks chiefly wild orange ^ Frilhling's landwirth. Zeitunt/, 1878. ^Die Kratdheiten der PJlanzen, 2ikI Edit., 1896, ii., p. -IWl. '* Bulletin de la soc. mt/coloij. de France, vii. ^ Revue vii/colo'/ique, 1891. ^ Handhuch d. Pflauzenkrankheiten, 1886. '' Berichle d. deutMch. hotan. Gesell, 189-2; Landwir/h. Jahrlnuh, 1894. "^ Extraits du Bulletin de VAcademie des sci. de Cracovie, 1892, 1893, 1894. * Schostakowitsch (Flora, 1895 (ergzbd.) distinguishes Cladosporium from other genera. ^Scribner, Bulletin of Torrey Cluh, xni., 1886, p. 181. Underwood, Journal of Mycolorjy, vii., p. .S4. Swingle and Webber, "Diseases of Citrous Fruits," U.S.A. Dept. of A> gennanica. 1 Eriksson, i5oton. Centralblatt, xxix., ISS7. Kirchner, ZeiLschrift /. Pflanzcn- krankheiten, i., 1891, p. 24. CERCOSPORA. 513 Cercospora. Conidia elongated and slender, olive-green, and septate. !My- celium greenish. "Distinguished Ity the vermiform septate conidia" (Massee). Cercospora circumscissa Sacc.^ This is a parasite which occurs on cultivated almond, peach, and nectarine, as well as on wild Primus serotina in the United States. The leaves are attacked while still young, and exhibit by reflected light a yellowish spot with a dark centre. The conidia arise on the spots as dark-green clusters, thereafter the diseased tissue shrinks, becomes detached, and falls out, leaving " shot-holes " not unlike those produced by species of Phyllostida. Defoliation may occur in severe cases of attack. As a result of the injury to the foliage, the new wood does not mature well, and second growth may take place during the same season ; shoots of this kind will probably dry up during winter. The fungus may also directly kill the tissue of twigs as far as the cambium. The fruit is never attacked directly, but may be seriously affected through the injury to leaves or twigs. In order to minimize the disease, it is recommended to burn all fallen foliage, and to turn the earth thoroughly below infected trees. Pierce obtained a crown of very healthy foliage on almond- trees treated with (1) ammoniacal solution of eojiper carltonate, and (2) modified eau celeste. C. persicae Sacc. On leaves of peach. (U.S. America.) C. acerina Hartig- appears on brown spots on the cotyledons, young leaves, and stalks of young plants of Acer. The conidia are grey, pluricellular, and slightly curved (Fig. .j14). The mycelium inhabits the intercellular spaces of the parts attacked, and forms resting sclerotia in the tissues of dead leaves. C. viticola (Ces.).^ This fungus is found in Europe and the United States on Vitis vinifcra and V. Lahriisca. It causes spots on the leaves, and from these arise close columns of septate conidiophores which give off thick pluricellular conidia. C. beticola Sacc.^ inflicts considerable injury on cultivated 1 Pierce, Joun^al of Myrolor/t/, vii., p. 6fi and p. 232. '^R. Hartig, Uvtermrhunijcn ajw d. forstbotan. Inatiliit, i., Municli. =^ Description and treatment in New York Agric. Exper. Station Report for 1890, p. 324. ^Thiimen, Die Behimpfuvq d. Pihkraid-heitcn tniatrer Kitllurtfeirdchae, 1886. 2k >u FUNGI IMPERFECTI. sugar beet and beet-root. It is easily recognized by the numerous sharply defined spots produced on the leaves. The conidia are very long and pluriseptate. In the United States this is one of the most serious of beet diseases.^ As preventive treatment, great care should be taken to destroy all infected material. A long rotation should also prove a good remedy. Fig. 314. — Ctrcospora acerina. 2, Seedling of Acur, with a cotyledon brown and withered, and a leaf partially so. 4, Section through a diseased cotyledon ; the conidiophores (d) emerge from the epidermis, and bear long tapering septate conidia ; e, sclerotia formed inside the diseased tissues for hibernation. 5, Ger- minating conidia. (After R. Hartig.) C. apii Fres. Common on celery (Ajnum gravcolens) and par- snips {Pastinaca sativa) throughout all Europe and North America. It causes leaf-spots at first yellowish then enlarging and turn- ing brown. The mycelium grows in the intercellular spaces of the leaf, and gives off tufts of conidiophores through the stomata. The conidia are long, tapering, obclavate bodies with an attachment-scar at their larger end." C. asparagi Sacc. occurs on asparagus in Italy ; C. caulicola AVint. frequents the same host in America. C. Bloxami V>. et Br. On Brassica in Britain. C. armoraciae Sacc. On horse-radish. ^ Pammel. Iowa Agric. Exper, Station Bulletin, la. 1891. ^Description in New Jersey Af/ric. Exper. Station Bulletin 2, 1891. C'EHCOSPORA. 515 C. resedae Fuck.^ This fungus is the cause of a garden mignonette disease very common in America and Europe. It causes little depressed spots with brownish or yellowish Ijorders, which begin as reddish discolorations of the leaf. The leaves gradually wither and dry up, so that tlie Howers suffer. The mycelium grows inside the leaves, and gives off tufts of conidio- phores through the stomata. The conidia are elongated, septate, and spindle-like or club-shaped. Spraying with Bordeaux mixture was found to give good results. C. cheiranthi Sacc. produces roundish leaf-spots on wall- flower, and, if severe, causes death of the leaves and premature defoliation of the plants. C. rosaecola Pass. This causes leaf-spot on cultivated and wild roses in the United States. The first indication of disease is the appearance of black spots with reddish margins. The conidiophores emerge from the stomata in tufts, and carry long obclavate conidia. C. angulata Wint. is one of the causes, of leaf-spot on currant, and occurs often in company with S'pftiria rilis. (U.S. America.) C. violae Sate, occiu-s on leaves of \'i()l(( odorata. C. malvarum Sacc. On species of Malva. C. althaeina Sacc. On hollyhock in the United States. C. neriella Sacc. causes leaf-spot on Nerium Oleander. C. Bolleana (Thlim.) pi'oduces olive-brown spots on leaves and fruits of the FIlt, injuring the crop. C. capparidis Sacc. On Capparis spiitosa in Italy. C. gossypina Cooke is given by Atkinson as a fungus frecjuently ))resent on diseased plants of cotton.- Saccardo records over 230 species of Cercospora, most of which cause spotting of living or fading leaves of many jilants, e.g. Phaseolus, Lupiniis, Trifolium, Vicia, Gleditschia, Solanum nigrum. Datura, RicimiSy Ampelopsis, Liriodendron, Tilia, Rosa, Fotentilla, Ruhus, Cydonia, Ptelea, Rhamnus, Euonyimcs, Ailanthus, Rhus, Sambucus, Vihurnum, Olea, Syringa, Morus, Fraximis, Coffea, Ligustrum, Mercurialis, etc. Heterosporium. Conidiophores simple or branched. Conidia olive, oblong, pluriseptate, and with a spiny or warty outer coat. ' Fairchild in Rejiort of Section of Vetjetab/e Pathology for 1889, U.S. Dept. of Agrioultiu'e. -Botajikcd Gazette, 1891, p. 61. 516 FUNPxI IMPERFECTI. "Resembling Hchnintliosporiurn in general habit and structure, in fact only distinguished by the minutely warted conidia " (Massee). Heterosporium echinulatum (Berk.)/ (Britain and U.S. America.) The " fairy ring spot " of. Carnations. This is a serious enemy of cultivated carnations, and causes great damage. It was first described by Berkeley in 1870 as a carnation pest. The symptoms are light-coloured spots on which are concentric rings of dark-coloured conidiophores. These arise from dark- coloured portions of the mycelium inside the leaf and give off conidia with three or more cells. The conidia are at first terminal, but after one has been formed the conidiophore branches laterally and produces another conidium, repeating this process for a considerable time. The spots are produced on leaves, leaf-stalks, and sepals, causing them to wither. In consequence the flowers do not unfold and the plants are rendered unsightly. Cultivation of the carnation in dry airy conditions is said to keep this disease in check. The following are British species occurring generally on fading leaves : H. variabile Cooke. On ,s])iiiach. H. ornithogali Klotzsch. On Ornithogalum^ Convallaria, and other species of Liliaceae. H. typharum C. et M. On Typha angustifolia. H. laricis C. et M. On larch needles. H. asperatum Massee.- Occurs as a parasite on Smilacina stellata. Napicladium. Conidia oblong, three or more celled, and produced singly on the end of short conidiophores. " Somewhat resembling Helmintlios23orivm and Brachys2)ormm, but distinguished by the less rigid fertile hyphae and the large solitary conidia " (]\Iassee). Napicladium (Helminthosporium) arundinaceum (Cord.). (Britain.) This lives parasitic on the leaves of rhrar/mitcs communis, and spreads rapidly from plant to plant. The leaves 1 Worth. (J. Smith, Gardentr\erk.'* This disease, first observed in Australia, is described by Smith as occurring in England. It attacks grasses, especially Fcstwa, during summer. The stems and ears are glued together l)y the fungus-stronia, and conidia are developed on all parts of the plants. 2. Ser. Phakostilbkae. Sect. PIi ru(fiii osporae. Isariopsis. Conidia pale-coloured, cylindrical, and pluricellular. Isariopsis griseola Sacc* ])roduces spots on leaves of living 1 Jhdwi-ila, 1877. p. 12.3. -M'Weeney, Iriah Xaturalisi, ISO"), ]•. '1~'^. •^ Worth. G. Smith, Diseases of Fijric. Exper. Station, 1887. Waite, Yearbook of U.S. Dept. of Afjricuitiire, 1895; ilescription ami treatment. 532 THE PATHOGENIC BACTERIA. diseased branches, and is one of those forms which does not liquefy gelatine. One characteristic reaction is, that as destruc- tion of the tree-rind proceeds, fermentation takes place with production of carbon dioxide, hydrogen, butyric acid, and alcohol. The bacterial colonies should be carefully cut out when detected. Bacteriosis of Carnations. Arthur and Bolley have recently described a bacterial dis- ease of carnations common in North America.^ It attacks the leaves almost exclusively, causing pale spots which later become whitish depressed areas. The plants are seldom killed outright and the leaves remain attached, but they are stunted in size, and the yield of flowers is prejudiced. The disease is favoured by poor cultivation in moist surroundings, and is more prevalent indoors. A very efficient remedy is to avoid watering the foliage, except at long intervals ; by means of wire-netting it is possible to water the roots without touching the foliage. (Edit.) Twig-galls of the Olive" (" liogna or Loupe "). Twigs of the olive are frequently beset with knots varying from the size of peas to that of hazel-nuts. These consist chiefly of parenchyma which begins to decay internally before the gall has ceased growing ; finally the gall also dies. In this way cavities in the twigs are formed in which Prillieux found large masses of bacteria {Bacillus oleae), to whose action he ascribes the formation of the galls, as well as the decay of the tissues. Infection from pure cultures is yet required to show whether the galls are really due to the action of the bacteria, and whether the above-mentioned Bacillus is the real cause. I had the opportunity of personally inspecting the disease on olives near Iviva, and found that the galls really contained nests of bacteria, while death of twigs above the galls was very frequent. Similar symptoms of disease occur on willow, birch, pine, and other trees, but they have not been investigated. 1 Arthur and Bolley, Purdue University Agric. Exper. Station, Bull., 59, 1896. -Prillieux, " Les' tumeurs bacilles de I'Olivier, etc.," Revue gener. de hotaiiique, 1889. t\vig-(;alls of the alepi'o pink. 533 Twig-galls of the Aleppo Pine.^ The galls occurring on the twigs and branches of Ft mis halcjM/isis are even larger than those on the olive ; they are particularly common in the woods near Coaraze in the Maritime Alps. The galls contain masses of bacteria situated in canals and cavities in the parenchyma, and throughout the woody tissues inside the galls. Prillieux regards bacteria as the cause of the galls, and he believes that they penetrate the healthy bark and form nests which kill the parenchyma. Experimental infection has, however, not yet been carried out. Canker of the Ash. Sorauer- regards the well-known ash-eaiiker as the result of the action of bacteria, but Noack thinks this improbable. Bacteria were found in the canker-spots only in summer, and might easily have got there accidentally after the formation of the galls. Galls of the ash caused by attacks of the insect Fki/toptas may frequently contain l.iacteria. Canker of the Ivy. Liudau-^ describes a cancerous formation on ivy-twigs, accom- panied by death of portions of the leaves. The diseased places contained slimy masses of bacteria, and the canker-spots, though at tirst isolated by formation of wound-cork, continued to extend till they reached the wood, which was ultimately killed. Ture- culture and infection-experiments were not carried out, and the author himself was unable to determine wiiether the bacteria were primary agents in the canker-formation or only late arrivals. Lilac Disease. Sorauer* observed masses of bacteria enclosed in cavities in young twigs of lilac which after becoming black-spotted had in many cases broken over. The attack and the part taken in it by the bacteria were not however investigated further. ' Vuillemin, " Sur une tuineur da I'in .rAleji,' Compl. rnul., cvii., 1SS8; Prillieux (loc. cit.). -Sorauer. Atla-s d. Pflanzenhankheilfn ; Noack, " iJer Eschenkrelm,'' Z'it- xchrij'f /. PflanztnkrankhtiUn, 181)3, p. 193. ■lArnXKn, Zeituchrift f. PflanzcnkrauklnHen, 1804, p. 1. ■•.Sorauer, Zeitschri/t /. Pflanztnkrankhtilen, 1891, p. 180, ami ls!»2, p. 3U. 534 THE PATHOGENIC liACTERIA. Bacterial Disease of the Mulberry.^ Cavities containing bacteria liave been found in brown spots on diseased leaves and twigs of tlie mulberry. A form " Bacterium mori " was isolated and found to reproduce the disease when used to infect healthy leaves. I have myself observed, in the arboretum of the forest experimental station at Munich, most of the new twigs' of an old mulberry tree beset with brown spots over the whole green tissue. The leaves on such twigs were not spotted, but died off prematurely. The spots indicated cavities filled with bacteria and a slimy substance. " Mai nero " of the Vine. This name is given to certain diseases of the vine, the cause of which has never been satisfactorily explained. Baccarini^ succeeded in obtaining all the symptoms of the disease after infecting healthy twigs by grafting on diseased pieces. Prillieux and Delacroix^ describe a similar disease prevalent in Tunis and throughout France, with the name " Aubernage." The wood when attacked exhibits black points which rapidly enlarge and coalesce, causing it to decay. All diseased elements were found to contain a brown gummy substance in which a. form of Zc^ji;o/;/in,«- bacterium swarmed. Inoculation of healthy vines produced the disease in the following year. Certain diseases of the grape have also been ascribed to bacterial action, and investigations are at present in progress. Sorghum Blight. A disease of species of Sorghum has been long known in America, especially on S. saccharatum, one of the sources of sugar. The symptoms are red or black spotting of the leaves and other parts of the plant. Tlie disease may even be severe enough to cause death of the host-plants. Burrill in 1886 found a bacterial form present in the spots, and named it Biicilhifi sorglii. Kellermann and Swingle'* obtained pure cultures, ' Boyer and Lambert, "Deux maladies du Mftrier," Compt. rend., cxvii., 1893. - Ma/]n(jhia, vi. ; also Bullet, d. Soc. hotan. Ital., 1894. •'"La gommose bacillaire d. Vignes," Comptes rend., cxviii., 18!)4. '* Report of botanical department of Kansas State Agrir. ColU'ije, 1889. SORGUUM BLIGHT. 535 and carried out successful experiments in infection of healthy Sorrjlium. Diseased tields should liave the SvrgJium stuhble burnt out, and other crops cultivated on them for several years. Bacterial Disease of Maize. ^ From dark slimy spots on young maize-plants which liad died from some unknown disease, Burrill isolated Bacillus m-cnlrs. Pure cultures were obtained and minutely described, but no record is given of its use in infection-experiments. Red-coloration of Wheat. This is a phenomenon not uncommon on wheat-grain, where it may be epidemic. Prillieux- ascribes it to a Mierucoccva which he found associated with it ; as, however, neither pure cultures were made nor any experiments in infection carried out, the cause of the disease is still doubtful. Examination of diseased grain showed that the starch-grains and I'ven cell-walls had been dissolved. Mosaic Disease of Tobacco. This disease of tlie tobacco is well known in the Xether- lands. It makes its appearance as a mosaic-like pattern on the leaf, due to isolated spots becoming light-green, then dying. Mayer ^ ascribes the disease to the influence of l)acteria, although infection-experiments have hitherto failed ; other observations on the disease do not confirm this conclusion. Potato-Rot.^ Ivuhn described a dry-rot or tuber-rot of the potato wliich had been known since 1830. The disease appears generally after harvest and lasts till spring. The tubers shrivel wy nnd become very brittle. 1 Burrill, Aijric. Exper. Station, Ciiir. of IUino{><, 1889. -Annah-< d. sci. natur., Ser. vi., 8, 1878, p. 248. »"lTeber tlie Mosaik-krankheit ties Tabaks," VersiichH-^tation, Vi.I. :V1, 1,S86. •* Kvihn, Die Krcuil-htitm d. Kidfiirnirh-hyccac \ (5) Gharaccae. Of these the Characcac includes no endophytes, the Co'iiju//(dac, Phacophyceae, and Ehodophyccae only species endophytic in other algae or in animals. The Chlorophyceas, however, include a large number of species which live as " aerial algae " endophytic in Phanerogams, either as shelter-parasites or as true parasites. I. CHLOROPHYCEAE. These are divided into three groups : ^ 1. Protococcoideae including the families Volvocaceac, Tetra- sporaceac, Chlorosphaeraceae, Fleurococcaceae, Frotococcaceae {Endos- pliacraccac, Characieae, Sciadiaceae), and Hydrodidyaccac. 2. Confervoideae including the families Ulvaceac, Ulothrichaccac, Chaetophoraceac Mycoidcaccae, Cylindrocapsaccae, Oedogoniaceae, Coleocliadaceae, Cladophoraceae, Gomontiaccae, and Spliaeropleaceac. 3. Siphoneae including the families Botrydiaccae, Phyllo- siphonaccae, Derhesiaceae, Vaucheriaceae, Bryopsidaceae, Caider- paceac, Codiaccac, Valoniaccac and Dasydadaceae. Chlorosphaeraceae. Chlorosphaera endophyta Klebs. This is found between the living epidermal cells of Lemiia rninor, and produces there spherical cell-masses visible to the naked eye as wart-like swellings. According to Frank, this is related to Bndodonivm poljiriuirplL urn Frank. Entophysa charae IMob. This lives under the cuticle of the e}jidermal cell-wall of Cliara Horiumanni in Brazil. Endosphaeraceae. Most of the species can penetrate into living organs, but they may also live as saprophytes or vegetate as independent organ- isms. That all the Endosphaeraceae are injurious to their host has not as yet been proved. Chhirochyfrinm inclwdes eight European species all endophytic in living i)liints. ' The aiiangeiiic'ut used by "Wille in Enfilcr-Prantl. uatur. Pflanzen-famUkii. CHLOROCHYTRIUM. 549 Chlorochytrium lemnae Cohn.^ The zygozoospores have four cilia and swarm for a short time in water. On plants of Lemna trisulca, the ciliated end becomes applied to the epidermis at the place where two cells are in contact, the zoospore becomes spherical, forms a membrane, and comes to rest (Fig, 324). It remains resting for a day or two, and assimilates so that a starch-grain is formed inside it. Next, a transparent process is given off which finds its way between the epidermal cells, widens out, and absorbs the cell-contents, while the portion of the algal Fio. 824. — CIdovochytrium Itntuae. n, //, '•, Ger- minating spores penetrating through the epi- dermis and between the cells of the parenchyma. A surface view shows the germinating spores from above. (After Cohn.) Fia. 325. — Clilorochijlnuiii lemnae in Lnnna trisulca. a, Mature ; /(, voting ; c, discharged sporangia. (After Klebs.) cell remaining outside becomes filled with cellulose and forms a firm button-like process. The young alga continues to make its way between the cells into the intercellular spaces of the subepidermal layers of parenchyma, jjrefjeraltly taking up its quarters in the thin anterior margin of the thalloid shoot, and avoiding the larger air-spaces. The zoospores are formed by repeated division of the plasma of the original cell ; they are enclosed in a gelatinous mass which swells and ruptures the membranes of the al"a as well as the tissue of the Lcmna. Cohn, B^itraije znr Bioloijie d. nkd. Orfianismtn ; Klebs, Tiotan. Zfitiuiii, 1881. 550 THE PATHOGKNIC ALOAE. The zoospores (gametes) copulate in the gelatinous mass which escapes, and break out from it as free swarming zygozoospores. When the Lcmna falls to the bottom in autunni, or when it dries up, the cells of the alga become resting-cells capable of sustaining drought. Plants of Lcmna seem to be little disturbed l)y attacks of the endophyte, and develop their flowers normally. Chi. Knyanum Kirchn. i'requents Lcmna minor and Z. f/ihba, CcratophyUvm demcrsum, Elodca canadensis, but not Lcmna trisulca. It forms zoospores only, and these on penetrating into a host do not produce a cellulose button like the species just described. They appear to be able to enter the host only by the stomata. Chi. pallidum Klebs. ({rows in the intercellular spaces of Jjcmna tri^mlen. Chi. viride Schroet. Found in the respiratory cavity of Kuniex oUiisifolins. (^ther species occur in dead Phanerogams or in Algae. Stomatochytrium limnan- ^^^,^.^^,^ - themum Ounningh. Inhabits \ Jf f If the respiratory cavity of leaves ** ^ ** ""^ of Limn anthem uni iiulicvm in India. Chlorocystis Cohnii Peinh. Occurs as a "shelter-parasite " Fio. 326.-.B»,(io.i, Chlora serotina, Erythraca Centaurium. This endophyte may either penetrate into living leaves and there go through its life-history, or it may do so in dead leaves. The zygozoospores have only two cilia, and enter the leaves chiefly through the stoniata of the lower surface. Inside the leaf they form long filaments, which make their way between the elements into the vascular bundles of the leaf-ribs, and follow the course of the spiral vessels. Kesting- spores are formed, and give the veins of the leaf a rosary -like appearance. Male and female gametes are pro- duced from the resting cells, and copulate to form zygozoospores. The host-plants are not injured by this endophyte. Chaetophoraceae. Most of the species are aquatic algae which live independent or as epi])liyt(\s. Endoclonium polymorphum Frank (see Chlorosphacra rndo- phyta Klebs). This form lives endophytic and sometimes intra- cellular in living or dead leaves of Lrmaii. Entoderma Wittrockii Wille occurs inside the wall of Ectorarpvs (Fig. 327). Periplegmatium and Phaeophila live endophytic in living algae. Trentepohlia endophytica (IJeinsch). In living cells and intercellular spaces nf Jungeruianniaceae (e.g. FruUania dilatata) and kills them. Fig. •A-ll. — Eiitoder wair in the membrane of a .species of Alga (AV^ocoz/h/s). A, \ young one-celled plant just after jjene- tration into the alga. B. Plant composed of several cells in the wall of EHnnn-iius. C, Plant which has formed sporangia of swarm - spores, one of which is discharged and another is in the act. (After Wille.) 052 THK I'ATHOGENIC ALCAE. Mycoidaceae. Cephaleuros Mycoidea, Xaisten ^ {Mycoidea jja?'as?!^/tYf, Cunning.).'^ This alga is epiphytic on the leaves of most trees and shrubs in the tropics. It varies considerably in its appear- Fio. 32S. — Cephaleuros Mycoidea. Section through the epidermis of a leaf of CamelUn, showing the thallus-like disc with haustoria. (After Cunningham.) ance, but generally forms flattened thalloid discs several layers of cells thick and attached firmly to leaves by means of rhizoids (Fig. 328). Hairs are produced from the thallus-discs, especially CDoni m& mnnmoi Fio. 329.— Cephaleuros Mycoidea. Section through part of an attacked leaf of Camellia. The epidermal layer has been ruptured, and haiistoria from the algal disc penetrate to the tissues. The dark-shadod portion is that killed by the alga. (After Cunningham.) the older ones ; in addition, sporangial structures are also developed and give off biciliate swarm-spores. The discs form a kind of cuticle which becomes completely fused with that of the leaves. ^ Karsten, Anna!, dajurdut. hotan. de Bniten:oracteriospermuni, Taphrina, 147, 149, 153 Bacteria, 530 Bacterium, - - 101,143,534,537 Balansae, Peridcrniium, - - - 417 balsameuni, Pcridermium, - - 417 balsamitae, Puccinia, bambusae, Neovossia, barbareae, Aecidium, Barclayana, Neovossia, Barclayella, - Barclayi, Phragmidium, Bardanae, Aecidium, Bargellinia, Barya, Baryanum, Pythiuin de, Baryi, Puccinia, basicola, Thielavia, Basidioniycetes, Basidiophora, batatas, Rhizoctonia, bataticola, Phyllosticta, Batschiana, Sclerotinia, Behenis, Uromyces, bellidiastri, Puccinia, Beloniella, berberidis, Aecidium, ,, Melasmia, , , Microsphaera, Berkeleyi, Puccinia, betas, Phoma, ,, Phyllosticta, ,, Rhizoctonia, ,, Uromyces, - beticola, Cercospora, betonicae, Puccinia, , , Ustilago, betulae, Hormomyia, , , Sclerotinia, ,, Taphrina, betulina, Dothidella, ,, Melampsora, - Taphrina, 147, 1 betulinus, Polyporus, Beyerinckii, Ascospora ,, Coryneum bicolor, Entyloma, Bidwellii, Laestadia, biennis, Endosphaera, biseptatum, Gymnosporangiu bistortae, Ovularia, , , Pseudopeziza, , , Pseudorhy tisma, ,, Puccinia, ,, Rhytisma, PAOE 355 311 40!) 311 373 363 351 138 184 4, 116 354 182 421 127 202 464 270 337 359 255 - 341 - 479 - 176 - 356 - 468 - 464 - 202 - 334 - 513 - 359 - 298 - 262 - 261 149, 154 - 230 366, 367 152, 159 - 446 - 211 211,491 - 312 - 216 - 555 - 401 - 501 - 256 - 255 - 355 - 246 I. INDEX OF PARASITES. 559 rAOE bistortariim, Ustilago, - - 298 Bivonae, Uncinula,- - 178 bliti, Cystopus, - 127 Bloxami, Cercospora, 514 Bolleana, Cercospora, - 515 Boltshauseri, Ascochyta, 473 borealis, Exoascus, - 158 ,, Polyporus, 439 l»ostrichoneuia, - 501 Botrytis, 4, 267, 499 boutelouae-humilis, Ustilago, - 299 bracbysporiim, Lophodermiui n, 233 Brachypuccinia, 353 Brandegei, Aecidium, - 411 brassicae, Alternaria, - 518 ,, Asochyta, 473 ,, Chytridiiim, - - 107 ,, Macrosporium, - 518 ,, Ctlpidium, - 107 Plasmodiophoia, 524 brassicicola, Sphaerella, - - 215 Breniia, . - - - 131 brevipes, Uromyces, 337 brevius, Perideriiiium, - - 415 broniivora, Ustilago, - 292 Brunchorstia, - - 481 Brunchorstii, Frankia, - 101 brunnea, Ramularia, - 502 bulborum, Sclerotina, 266 bulbosuni, Phragmidium, 363 Bulgaria, . 253 bullata, Puccinia, - - 353 Taphrina, - 14S, IS 0. 154, 168 Ustilago, - ■ 288 bullatum, Tolyposporium, - 306 bunii, Aecidium, - 355, 409 ,, Puccinia, - 356 Burillia, .... 322 butomi, Cladochytriuin, ■ 114 buxi, Laestadia, 217 ,, Puccinia, - 361 Byssothecium circinans, - - 201 C cacaliae, Uromyces, - 337 Caeoma, 364, 418 calamagrostidis, Tilletia, - 310 calcea, Ramularia, - - 502 caleudulae, Entyloma, . - 312 californica, Plasmodiophora, Calonectria, . Calosphaeria, . calospora, Tilletia, - calthae, Pseudopeziza, - ,, Puccinia, - Calyptospora, - Camarosporium, camelliae, Coryneuin, ,, Meliola, - campanulae, Coleosporiuni, ,, Marsonia, - ,, Puccinia, - cancellata, Koestelia, Candida, Peronospora, candidus, Cystopus, Candolleana, Sclerotinia, Candollei, Phonia, - canescens, Entyloma, cannabis, Septoria, - capensis, Ustilago, - Capnodium, - capparidis, Cercospora, - carbonarium, Phragmidium, caprearum, Melampsora, cardui, Puccinia, ,, U.stilago, caricicola, Puccinia, caricis, Cintractia, - ,, Puccinia, - ,, Ustilago, - caricinum, Leptostroma, caries, Tilletia, carnea, Taphrina, - 148, 149, carneola, Ovularia, . cameum, Myxosporium, - carpinea, Dermatea, carpini, Melampsora, Taphrina, - 147, 150, Carpoasci, carpophilum, Cladosporium, carthami, Puccinia, caryogenum, Fusicladium, caryophyllinus, Uromyces, Casparyana, Schinzia, cassandrae, Exobasidium, castagnei, Melampsora, - ,, Podosphaera, - ,, Puccinia, 253 370 153, 162 560 I. INDEX OF PARASITES. castagnei, Sphaerotheca, castaneae, Diplodina, ,, Septoria, catalpae, Macrosporium,- catenulatum, Entyloma, - caulic«)la, Cercospora, caiilium, Melanotaeniuni, ceanothi, Aecidiuni, cecidomophilus, Taphrina. cedri, Peridermium, cellulicola, Scliinzia (Naegeli celtidis, Kamularia, celtis, Taphrina, Cenangium, - cenchri, Tolyposporium, centaureae, Aecidium, ,, Piiccinia, cephalanthi, Aecidium, Cephaleuros, - Cephalotheca, cepulae, Urocystis, - cerasi, Fusicladium, ,, Puccinia, ,, Taphrina, 19, 147, V. cerasina, Septoria, - cerastii, Aecidium, - , , Melampsorella, cerastiorum, Fabraea, Geratocystis fimbriata, Ceratophorum, cerealis, Gibellina, - cerebrum, Peridermium, Cercospora, Cercosporella, cercosporoides, Cylindrosporium , Cesatii, Tuburcinia, chaetomium, Coleroa, Chaetophoraceae, - Charrinia, cheiranthi, Cercospora, chelidonii, Caeoma, chenopodii, Phyllosticta, ,, Uromyces, Chlorochytrium, Chlorocystis Cohnii, Chloropliyceae, Chlorosphaera endophyta Chlorospliaeraceae, Choreocolax, - I'AOK PAGE - 173 chrysanthemi, Oidium, - 499 - 474 Septoria, - 478 - 478 Chrysochytrium, - - 111 - 518 Chrysomyxa, - 20, 54 377 - 313 chrysosplenii, Entyloma, - 312 - 514 ,, Puccinia, - 361 - 314 Chrysospora, - 361 - 411 Chytridiaceae, - 11, 106 - 147, 152 Ciboria, - - . - 270 - 417 cichoriacearum, Erysipiie, 175 i). - 326 Cicinobolus Cesatii, 470 - 502 cicutae, Puccinia, - - 355 48, 149, 153 cinarae, Ramularia, 502 - 251 cinerariae, Aecidium, - 352 - 306 cinerea, Botrytis, - - 180, 267 499 - 351 „ Monilia, - 261 - 353 cingens, Melanotaenium, 314 - 411 cingulatum, Gloeosporium, - 485 - 552 cinnabarina, Nectria, - 8 17, 71 185 - 178 cinnamomeus, Polyporus, - 452 - 316 cinnamonea, Dermatea, - 253 - 507 Cintractia, 301 . 355 circaeae, Aecidium, 409 51, 153, 163 ,, Melampsora, 370 - 476 ,, Puccinia, - 361 - 410 circinans, Coleroa, - 195 - 370 ,, Leptosphaeria, - 201, 221 - 255 , , Vermicularia, - 471 - 469 circinata, Uncinula, 178 - 511 circumscissa, Cercospora, 513 - 220 cirsii, Phyllosticta, 464 - 414 ,, Puccinia, 340 - 513 citri, Capnodium, - 182 - 503 ,, Meliola, - 181 urn, - 489 Cladochytriaceae, - 113 - 322 Cladochytrium, 114 - 195 Cladosporium, 508 - 551 cladosporoides, Cercospora, 506 - 472 Clasterosporium, 511 - 515 clavariaeforme, Gymnosporangium, 384 - 419 Clavarieae, 431 - 465 clavellosum, Triphragmiiim, 362 - 337 Claviceps, 191 - 549 clavipes, Gymnosporangium, 402 - 550 claytoniae, Peronospora, 134 - 548 clematidis, Aecidium, - - 349 409 - 548 Clithris, - - 248 - 548 Cocconii, Tolyposporium, - 306 - 555 cochleariae, Ovularia, - - 500 I. INDEX OF PARASITES. 561 coerulescens, Tapluina, 148, 150, 154, coicis, Ustilago, .... colchici, Urocystis,- ,, Urorayces, Coleopuccinia, . . . . Coleosporium, . . . . Coleroa, Colletotrichum, .... Colpoma, coliimnare, Aecidiuni, - - 372, coniari, Doassansia, commune, Nostoc, ... - communis, Erysiphe, Taphrina, 147, 151, 152, complanatum, Peridermium, - 415, compositarum, Aecidiuni, concentrica, Pestalozzia, condylonema, Cladosporium, - confluens, Caeoma, confiisa, Taphrina,. - 147, 151, confusum, Gyniuosporangium, congesta, Graphiola, conglomerata, Puccinia, - conglutinata, Pleospora,- conicum, Gymnosporangium Coniothecium, Coniothyi-ium, conorum, Aecidiuni (Peridermium) consimilis, Septoria, controversa, Tilletia, convallariac, Aecidium, - ,, Dendropiioma, convolvulacearum, Cystopus, convolvuli, Puccinia, coralloides, Urocystis, - Cordyceps, cornicola, Phyllosticta, - ,, Septoria, - cornu cervi, Taphrina, Cornuella, Cornui, Peridermium, cornuta, Roestelia, - coronata, Puccinia, - coronifera, Puccinia, Corticium comedens, coruscans, Peridermium corydalis, Entyloma, ,, Perouospora, coryli, Gnomoniella, 29, 147, 149, 381, 385, 391, PAOE 167 294 316 338 403 374 195 486 248 409 324 544 175 157 416 409 494 510 419 152 401 511 391 517 471 410 477 309 410 469 127 341 319 184 464 478 153 322 415 392 346 346 452 416 312 134 224 ill. PAGE 224 491 475 292 312 474 476 150, 153, 166 - 337 - 202 -■ 380 - 282 - 246 - 489 - 475 138, 170 - 134 - 510 - 510 - 428 - 469 - 206 - 204 - 188 coryli, Mamiania, - Coryneum, Couturea, Crameri, Ustilago, - crastophilum, Ent^'loma, crataegi, Actinonema, ,, Septoria, - Taphrina, 14 cristatus, Uromyces, crocorum, Rhizoctonia, - Cronartium, - cruenta, Ustilago, - Cryptomyces, - Cryptosporium, Cryptostictis, - Ctenomyces, - cubensis, Peronospora, - cucumerinum, Cladosporium cucumeris, Cladosporium, ,, Hypnochus, - cucurbitacearum, Phoma, Cucurbitaria, - Cucurbitarieae, cucurbitula, Nectria, Cunninghamianum,Gymnosporangium403 cupulatum, Synchytrium, - - 111 cyani, Aecidium, . . . . 409 Cyanophyceae, ... - 541 cycadearum, Anabaena, - • - 544 cyclaraeneae, Colletotrichum cyclaminis, Septoria, - - - 478 Cycloconium, - - - - 12, 506 cydoniae, Hendersonia, - - - 475 Phoma, - - - 468 Cylindrosporium, . - - - 488 cynodontis, Phyllacliora, - - 229 ,, Ustilago, cynoglossi, Peronospora,- - - 134 cynosbati, Crj'ptostictis, - - 475 cypericola, Schiuzia, - - - 326 Cystopus, - - - - 28, 123 ,, haustoria, - - - 13 ,, oogonia, - - - 47 ,, spore-germination, 47, 60 cystosiphon, Pythium, - - - 117 cytisi, Diplodia, - - - - 209 ,, Peronospora, - - - 133 „ Phyllosticta, - - - 463 Cytospora, 471 2 N 562 I. INDEX OF PARASITES, PAdE Didymaria, - - - - Dacromycetes, 422 Didymosphaeria, ... - dactylidis, Uromyces, - 336 Didymosporium, - - . - Darluca, 474 digitalis, Ascochyta, Dasyscypha, - 270 digitariae, Ustilago, Decaisneaua, Schroeteria 328 digitata, Schinzia, - - - - ilecipiens, Endoniyees, - 141 digraphidis, Puccinia, ,, Synchytriuin,- 109 Dilophia, ,, Taphrina, 147, 151 153 Dilophospora, .... Tilletia, - 310 Dimerosporium, .... decolorans, Exobasidium 427 dioicae, Puccinia, .... deformans, Barclayella, - . 373 Diorchidium, - - - - - ,, Caeoma, - 30 ,418 Diplodia, , , reridermiuni, 416 diplodiella, Coniothyrium, Taphrina, \4 7, 150, 153 , 165 Diplodina, „ Uromyces, - 418 diplospora, Ustilago, Dehnii, Beloniella, - 256 Dipodascus, Delastrina, Schroeteria, - 328 dipsaci, Peronospora, Dematieae, 505 discoideum, Exobasidium, Dematophora, 202 Discomycetes, .... dendriticum, Fusicladium, - 218 , 507 Discosia, ,, Venturia, - 218 discosioides, Pestalozzia, Dendrophoma, 469 dispersa, Puccinia, - - - 347 densa, Pkismopara, 131 ditissima, Nectria, - - - . densissinia, Microsphaera, 176 diversidens, Hydnum, - dentariae, Puccinia, - 359 Doassansia, Depazea, - 465 domestica, Ustilago, depazeaeformis, Sphaerella, - 215 Dothidea, depressum, Fusichvdium, - 508 Dothideaceae, - - - 184 Dermatea, 253 Dothidella, Dermateaceae, 251 Dothiora, Dermatella, - - 252 Douglasii, Botrytis, - 4, 269 desmodii, Ramularla, -. 502 drabae, Aecidium, - . - - destruens, Agaricus, - 462 ,, Puccinia, . - . - ,, Brunchorstia, - 252 , 481 dracontii, Aecidium, ,, Fusichxdium, - 508 dryadeus, Polyporus, ,, Oidium, - 499 dryadis, Didymosphaeria, ,, Ustihigo, 289 Duriaeana, Ustilago, de%'astans, Myxosporium , 486 Dysconiycopsis rhytismoides, - devastatrix, Phragmidium, - 362 Diachora, 230 E dianthi, Ascoc-hyta, - 473 echinata, Ustilago, „ Septoria, - 477 echinatum, Triphragmium, - ,, Sorosporium, 325 echinulatum, Heterosporium,- Diatrypeae, 226 Ectrogella, dicentrae, Aecidium, 410 effusa, Peronospora, Dicoccum, 506 effusum, Fusicladium, - dictyospermum, Pythiun 1. 117 Ehrcnbergii, Sorosporium, didyma, Septoria, - 478 Elaphomyces,- ... 97 I. INDEX OF PARASITES. 563 elatinum, Aecidium, elegans, Cladosporium, - Eleutheiomyces, elliptica, Peronospora, - Ellisii, Ascochyta, - ,, Entyloma, - ,, (iyninosporangiuni, elymi, Puccinia (Rostrupia), empetri, Caeoma, - ,, Chrysomyxa, - ,, Melasmia, ,, lihytisma, eudiviac, Puccinia, - Endoclonium polymorphuni, endogcnum, Melaiiotaenium, Endomyces, - Endophyllum, Eudosphaera, - Endosphaeraceae, - Engelmanni, Peridcrmiuni, Englerianum, Aecidium, enormis, Puccinia, - Entoderma Wittrockii, - Entomophthoreae, - Entomosporium, Entonenia, Entophysa charae, - Entorrhiza, entorrhiza, Ustilago, entospora, Basidiophora, Entyloma, ephedrae, Peridermium, Epichloii, epidermidis, Didymosphaeri. epilobii, Plasmopara, ,, Ramularia, ,, Septoria, - ,, Sphaerotheca, - epilobii-tetragonii, Puccinia, epiphylla, Taphrina, 20, 147, Tilletia, - epiphyllum, Cladosporium, epitea, Melampsora, erectum, Aecidium, Eremascus, Eremotliecium, ericae, Hypoderma, erigeronatum, Aecidium, eriobotryae, Fusicladium, 18, 72, 150, PACK PAGE "2, 404 eriopbovi, Puccinia, - 352 - 509 errabunda, Phoma, - 469 - 184 ervi, Uromyces, - 333 - 135 eryngii, Entyloma, - - 312 - 473 Erysiphe, - 175 - 313 Erysipheae, - 7, 170 - 402 ,, haustoria, - - 9, 10 - 354 ,, remedies, - - 68 - 380 erysiphoides, Oidium, - - 499 - 380 erythronii, Uromyces, - 338 - 479 erythrostoma, Gnomonia, - 222 - 246 esculenta, Ustilago, - 294 - 355 esculentum, Aecidium, - - 410 48, 551 euonymi, Caeoma, - - 368, 419 - 314 ,, Mici'osphaera, - - 176 - 141 Eupezizeae, - - 270 - 403 Euphacidieae, - - 241 - 550 euphorbiae, Aecidium, - - 24, 410 - 548 ,, Peronospora, - 135 - 417 ,, Uromyces, - - 334 - 409 euphorbiae-dulcis, Melampsora, - 370 - 359 euphorbiae-sylvaticae, Endophyllum, 403 - 551 euphrasiae, Coleosporium, - 376 - 115 Eu-puccinia, - - 340 - 480 Eurotium, - 178 - 555 excavatus, Uromyces, - - 337 - 548 Excipulaceae, - - 482 - 326 exitiosum, Polydesmus, - - 221, 518 - 297 ,, Sporidesmium, - 221 - 127 Exoasceae, - - - H ,41, 52, 144 - 311 galls, - 25,29 - 417 Exoascus (sec Taphrina), - 147, 152 - 190 Exobasidiaceae, - 423 - 218 Exobasidiuni, - - 7, 13, 423 - 131 galls, - - 21, 25, 28 - 502 exotica, Septoria, - - 478 - 478 expansa, Puccinia, - - 359 - 174 extensa, Taphrina, - - 148 - 341 extensicola, Puccinia, - 351 152, 158 - 310 F - 510 fabae, Uromyces, - - 333 - 368 Fabraea, - 255 - 349 fagi, Phytophthora, - 117 - 138 fagicola, Actinonema, - - 474 - 138 fallaciosa, Physalospora, - 218 - 234 farinosa, Melampsora, - - 368 - 411 farinosum, Oidium, - 173, 499 • 507 Farlowii, Taphrina, - 147, 51, 152, 157 5G4 I. INDEX OF PARASITES. fascicularis, Botrytis, fasciculata, Taphrina, fasciculatiim, Fusicladiuni, Fenestella, Fergussonii, Puccinia, - festucae, Puccinia, ,, Urocystis, ficariae, Cylindrosporium, ,, Peronospoia, ,, Uromyces, - Hci, Uiedo, ficuuiii, Ustilago, - filanientosiim, Peridermium, filicina, Taphrina, - ,, Uredinopsis, tilipendulae, Cj'lindrosporiu: Triijhragmium, ., Urocystis, - tilum, Darluca, fimbriata, Ceratocystis, - ,, Gnomoniella, - ,, Mamiania, fimbriatuni, Sphaeronema, firma, Puccinia, Fischeri, Entyloma, ,, Peridermium, Tilletia, - ,, Ustilago, - Fistulina hepatica, - flaccidum, Cronartium, - flammulae, Cladochytrium, fiava, Taphrina, Florideae, rtosculorum, Ustilago, foeda, Chaetophoma, foedum, Capnodium, foliicola, Hendersonia, - fomentaritis, Polyporus, - Femes (see Polyporus). fragariae, Ascochyta, ,, Sphaerella, fragariastri, Phragmidium, Frankia, fraxini, Actinonema, ,, Aecidium, - ,, Hysterographium, ,, Scolecotrichum, - ,, Septogloeum, ,, Septoria, - - 500 148, 149, 154 oOS 229 359 349 316 489 134 337 420 299 415 148, 149, 154 - 141, 420 m, - 489 - 362 - 319 - 474 - 469 - 223 - 223 - 469 - 351 - 312 - 377, 414 - 310 - 281 - 452 - 382 - 114 148, 150, 154 - 555 - 294, 295 - 181 - 181 - 475 74, 84, 435 473 214 363 101 474 410 232 508 496 478 fructigena, Monilia, fructigenum, Gloeosporium, frustulosum, Stereum, - fuciformis, Isaria, - Fuckeliana, Sclerotinia, fulgens, Synchytrium, fuliginosa, Scleroderris, - fulvum, Cladosporiuni, - ,, Polystigma, ,, Sclerotium, fulvus, Polyporus, - Fumago, fumariae, Caeoma, - fumosus, Polyporus, funerea, Pestalozzia, Fungi, classification of, - Fungi imperfecti, - Fusarium, fusca, Puccinia, fusco-violaceuni, Sistotrema, fuscum, Entyloma, fuscns, Protomyces, Fusicladium, - Fusicoccum abietinum, - fusiforme, Phragmidium, Fusisporium, Fusoma, 184, PAOE 261, 497 - 482 - 430 - 519- - 267 - 109 - 251 - 510 - 190 - 431 447, 448 181, 519 - 419 - 452 - 493 - 105 - 462 , 189, 520 - 356 - 433 - 312 - 141 - 507 - 465 - 362 - 521 - 504 galanthi, Sclerotinia, galanthina, Botrytis, galeopsidis, Erysiphe, ,, Phyllosticta, galii, Melampsora, ,, Puccinia, ganglioniformis, Peronospora, Gasteromycetes, geicola, Depazea, genistae, Didymosphaeria, , , Uromyces, genistalis, Darluca, gentianae, Puccinia, geographicum, Asteroma, geraiiii, Plasmopara, ,, Puccinia, - ,, Ramularia, ,, Uromyces, - ,, Venturia, - Gibbera, 27a 50O 175 465 370 341 131 422 465 218 337 474 341 470 131 359 502 334 218 204 I. INDEX OF TARASITES. 565 Gibberella, - - -. ■ - 184 gibberosa, Puccinia, 346, 354 Gibelliana, Sphaerella, - - 215 Gibellina, - 220 giganteum, Peridermium, - 416 giliae, Aecidium, - - 411 ,, Puccinia, - 355 gilv'um, Lophodermium, - 240 githaginis, Magnusiella, 14 S, 151, 154 gladioli, Urocystis, . 316 glaiicum, Penicilliuni, 3, 180 glechoruatis, Puccinia, - - 361 globosum, Gymnosporangiuni, - 403 ,, Synchytrium, - 113 Gloeosporiuin, - 482 glomerulata, Tilletia, - 310 glomerulosum, Clasterosporiui n, - 511 glumaruni, Puccinia, - 348 Uredo, - - 420 glytyrrhizae, Uromyces, - 337 Gnomonia, 17, 222 Gnomoniella, - - 223 Goeldiana, Ramularia, - - 502 Goeppertiana, Calyptospora, - 370 ,, ^Melampsora, - 370 ,, Ustilago, - 298 gongrogeua, Diplodia, - 472 ,, Pestalozzia, - 494 gossypii, Colletotrichum, - 487 Uredo, - - 420 gossypina, Cercospora, - - 515 Sphaerella, - - - 214 gracile, Helminthosporiuni, - 512 ,, Pliragniidiuni, - - 363 Pythiuni, - - 117 gramiueuni, Helniinthosporiu n, 221, 512 graminicola, Ascochyta, - 473 ,, Sclerospora, - 131 graininicolum, Exobasidium, - 427 graminis, Dilophia, - 222 Dilophospora, - - 479 ,, Erysiphe, - 175 ,, Ophiobolus, - - 222 Phyllachora, - - 229 ,, Puccinia, 75, 341 ,, Scolecotrichum, - 508 graminum, Septoria, - 477 Typhula, - 431 grammica, Ustilago, - 294 grandis, Ustilago, - - . . Graphiola, grisea, Peronospora, griseola, Isariopsis, grossulariae, Aecidium, - ,, Microsphaera, - Phyllosticta, Guariuonii, Microsphaera, Guepini, Pestalozzia, gunnerae, Nostoc, - . - . guttata, Phyllactinia, Gj'mnoasci, Gymnoascus, - - - - 138 Gymnosporangium, 48, 51, 74, 332 PAGE 293 325 134 519 409 176 464 176 494 541 178 137 , 170 , 383 deformations, 18, 43 Halstedii, Plasmopara, - - 131 Harknessii, Peridermium, - 415 Hartigianum, Septogloeuni, - - 495 Hartigii, Melampsora, - - 368 ,, Pestalozzia, S3, 491 ,, Polyporus, - 447 Harveyella mirabilis, - 555 hederae, Septoria, - - 478 hedericola, Sphaerella, - - 215 hedysari-obscuri, Uromyces, - - 338 helianthi, Aecidium, - 340 ,, Puccinia, - 340 Helieobasidium, - 429 helioscopiae, Melampsora, - 370 hellebori, Ramularia, - 502 Helminthosporiuni, 512, 516 helosciadii, Entyloma, - - 312 Helotieae, - . . . - 256 Helvellaceae, - - - . - 275 helvetica, Puccinia, - 353 Hemibasidii, .... - 275 Hemileia, .... 32, 361 Hemipuccinia, - 353 Hendersonia, .... - 474 Hennebergii, Phoma, - 467 hepatica, Fistulina, - 452 hepaticae, Aecidium, - 409 herbarum, Cladosporium, 4, 509 Herpotrichia, - - 61 , 83, 198 herpotrichoides, Leptosphaeria, - 220 hesperidearum, Pleospora, - 221 Hetcropuccinia, - 341 566 I. INDEX OF PARASITES. heterogenea, Puccinia, - - 360 heteroica, Sclerotinia, - 263 Heterosphaeria, - 249 Heterosporiuni, - 515 heterosporium, Fusarium, . 520 heterosporuin, Septospoiiuni, - 51S hieracii, Puccinia, - - 353 himalayensis, Chrysomyxa, - - 379 hippuriJis, Aecidium, - - 33G hirsutum, Sterevun, - 429 hirsutus, Polyporus, - 452 hispidus, Polyporus, - 444 Holboelli, Puccinia, - 359 holostei, Ustilago, - - 297 hordei, Hormodendron, - - 505 „ TiUetia, - - 310 ,, Ustilago, - - 288 Hormodendron, - 505 hottoniae, Doassansia, - - 324 hyacinthi, Bacillus, - 538 Pleospora, - 221 hyalina, Theeaphora, - 324 Hydneae, - 431 Hydnum, - 431 hydrangeae, Septoria, - - 478 hydropiperis, Sphacelotheca, - 302 Hymenomycetes, - - 422 hyoscyami, Peronospora, - 134 hypericorum, Melampsora, - 370 Hyphomycetes, - 496 Hypnochaceae, - 428 Hypnochus, - - 428 Hypocreaceae, - 184 Hypodernia, - - 233 Hypodermieae, - 233 Hypodermella, - 234 hypodytes, Ustilago, - 293 hypogaea, Niptera, - 254 Hypomyces, - - 184 liypophylluni, Cladosporiuni, - 511 Hysteriaceae, - - 232 Hysterineae, - - 232 Hysteriuiii, - 237 Hysterographiuni, - - 232 1, 1 impatientis, Depazea, impressuni, Asteroma, inaequale, Fusonia, infestans, Phytophthoi inflata, Rhizina, inquinans, Bulgaria, ,, Pestalozzia. insidiens, Pestalozzia, insititiae, Taphrina, 147, 15 intermedia, Doassansia, - ,, Ustilago, intermedium, Pythium, - interstitialis, Ovularia, - ,, Puccinia, - inulae, Coleosporium, ipomoeae, Coleosporium, ,, Nectria, , , Puccinia, ipomoearum, Vermicularia, ipomoeae-pandui-anae, Cystopus, iridis, Aecidium, - ,, Cladochytrium, - ,, Puccinia, ,, Uredo, - Irmischiae, Paipalopsis, - Isaria, Isariopsis, . . . . ischaemi, Ustilago, italica, Urocystis, - italicum, Penicillium, PAGE - 465 - 470 - 505 7, 119 - 273 - 253 - 494 - 494 )3, 164 - 324 - 295 - 117 - 500 - 341 - 376 - 377 - 189 - 356 - 471 - 127 - 411 - 114 - 355 - 420 - 322 - 519 - 519 - 292 - 319 - 180 igniarius, Polyporus, - 35, 433, 441 ,, ,, var. pinuum, 447 Jamesianum, Aecidium, - - 411 Jenseni, Ustilago, - - 288 Johansonii, Taphrina, 147, 150, 152, 157 ,, Urocystis, - - 319 juglandinum, Cladosporium, - - 510 juglandis, Marsonia, - 491 ,, Miorostroma, - - 497 junci, Puccinia, - 354 ,, Tolyposporium, - - 305 ., Urocystis, - 319 Uromyces, - 336 juncicolum, Rhytisma, - - 246 juniperi, Clithris, - - 248 ,, Stigmatea, - 211 juniperinum, (iymnosporangium - 391 ,, Lophodermium, - - 240 I. INDEX OF PARASITES. 567 PAGE Kaufmanniana, Peziza, - 265 kentiae, Colletotrichuni,- 488 Kerneri, Sclerotinia, 270 Klebahni, Peridermium, - 376, 414 Kmetiana, Urocystis, 319 knautiae, Peronospora, - 132 Knyanum, Chloroohytrium, - 5o0 Kochii, Strickeria, - - - - 205 Kolaczekii, Ustilago, 292 KoUeri, Ustilago, .... 287 Kociidersiaiia, Ustilago, - 298 Kriegerianum, Cladochytrium, 114 Kruchii, Taphrina,- - 147, loO, 158 Kiihneana, Ustilago, 298 L l-abrella, 480 laburni, Cuciirbitaria, S, 206 ,, Physalospora, - 218 laceianum, Phragmidium, 363 lacerata, Roestelia, 385 Lachnella, .... 272 laoiniata, Thelephora, - 429 lactea, Ovularia, - 500 laotucae, Bremia, - 131 Laestadia, .... 216 laetuni, Synchytrium, in laevigatas, Polyporus, - 445 laevis, TiUetia, 309 Lagenariuin, CoUetotrichuin, - 486 Lagerheiniii, Leuconostoc, 143 ,, Ustilago, - 299 lamii, Ovularia, 501 lampsanae, Puccinia, 340 ,, Ramularia, - 502 laneola, Myxosporium, - - 486 lapponicus, Uroniyces, - - 337 laricina, Sphaerella, - 211 laricinum, Leptostroma, - - 212 ,, Lophodermiuni, - 240 laricis, Caeoma, - - .S6G, 3t 7,419 „ Heterosporiuni, - - 516 ,, Hypodermella, - 234 Lasiobotrys, .... - 182 lathyri, Thecaphora, - 324 lathyrinum, Dicoccuni, - - 506 Laurencia, Taphrina, 29, 148, 1- 19, 153 laureolae, Sphaerella, - 215 lauri, Exobasidium, ledi, Chrysomyxa, - ,, Exobasidium, - ,, Sclerotinia, leguminosarum, Rhizobiuni, Leimbachii, Urocystis, - leniuae, Chlorochytrium, ,, Cornuella, - ,, Olpidiuin, - lepidii, Aecidium, - lepigoni, Cystopus, - leproides, Oedouiyces, - leproidum, Entylonia, Leptopuccinia, leptosperma, Peronospora, Leptosphaeria, Leptostroma, ... Leptostromaceae, - leptostromiforme, Cryptospori Leptothyrium, Letendraea, - leucanthemi, Aecidium, - ,, Puccinia, - Leucochytrium, leucogonium, Oidium, Leuconostoc, - leucospermum, Aecidium, lichenoides, Nostoc, ligustri, Aecidium, - ,, Caeoma, liliacearum, Puccinia, limbalis, Phyllosticta, limonii, Uromyces,- limonis, Fusarium, - limosae, Puccinia, - limosellae, Doassansia, - linariae, Entyloma,- ,, Peronospora, Lindemuthianum, Colletotric lineolatus, Uroniyces, Liidiartiana, Monilia, lini, Melampsora, - ,, Peronospora, - lolii, TiUetia, - longipes, Taphrina, - longissima, Phoma,- ,, Puccinia, ,, Sphaerella, , , Ustilago, PAGE 31,427 - 378 31, 427 - 263 101 317 549 322 107 410 127 313 313 359 134 220 480 479 489 479 184 351,409 351 112 499 143 409 546 409 419 356 464 334 521 351 324 312 134 hum, - 336 - 261 ■ 369 - 134 - 310 151, 152 - 469 - 354 - 215 - 293 568 1. INDEX OF PAKASITES PAGE lonicerae, Lasiobotrys, - - - 1S2 ,, Miciosphaera,- - - 176 lophanti, Peronospora, - - - lo4 lophiostomoides, Phoma, - - 467 Lophoilermium, .... 235 lucillae, Sphaerella, - - - 476 Ludwigii, Saccharomyces, - 141, 143 lumiuatum, Caoonia, - - - 419 lupini, Uromyces, . - - - 337 lutescens, Taphriiia (Magtuisiella), 148, 149, 154 luzulae, Urocystis, - - - - 316 Ustilago, - - - - 294 lychuicola, Ovularia, - - - 500 lychnidis, Septoria, - - - 478 lycii, Microsphaera, - - - 176 lycopersici, Colletotrichum, - - 487 ,, Fusariuin, - - - 520 ,, Septoria, - - - 477 lycopi, Aecidium, - - - - 411 macrocarpum, Cladosporium, - 510 macropus, Gynmosporaiigium, 391, 402 macrosora, Uredo, - - - - 420 Macrosporium, - - - - 517 macrosporum, Aecidium, - - 411 ,, Hysterium, - - 237 ,, Lophodermium, 34, 237 macrosporus, Protomyces, - 31, 138 maculaeformis, Venturia, - - 218 maculans, Ascochyta, - - - 473 niaculare, Asteroina, - - - 470 maeulatum, Entomosporiutn, - 480 maculifoimis, Laestadia, - - 216 Phyllosticta, - - 464 Magelhaenicum, Aecidium, - - 409 Magnusia, 178 Magnusiana, Puccinia, - - - 349 Magnusiella (see Taphrina), 146, 148, 151 Magnusii, Pjndomyces, - - - 143 ,, Entyloma, - - - 312 ,, Puccinia, - - - 350 major, Ustilago, .... 297 mali, Hendersouia, - - - 475 nialoruni, Sphacropsis, - - - 472 malvacearum, Phoma, - - - 469 ,, Puccinia, - - 359 malvarum, Cercospora, - - - 515 PACE nialvarum, Colletotrichum, 487 malvicola, Ascochyta, - 473 Mamiania, .... 223 mammillata, Puccinia, - 355 Marconii, Dendrophoma, 469 marginalis, Ustilago, 298 marginatus, Polyporus, - 449 Mariae-Wilsoni, Aecidium, 410 maritimus, Uromyces, - 336 Marsonia, .... 490 506 Martianoffiaua, Doassansia, 324 martii, Erysiphe, - 175 Masseela, .... 361 Mastigosporium, 504 maxima, Tuberculina, - 328 maximus, Cryptomyces, 246 maydis, Puccinia, - 353 ,, Ustilago, - 279 megalospora, Sclerotinia, 260 Melampsora, - - - 48, 53 363 Melampsorella, 370 melampyri, Aecidium, - 349 ,, Coleosporium, 376 Melanconideae, 226 Melanconieae, 482 melangeae, Gloeosporium, 483 melanogramma, Schizonella, - 305 Melanomeae, .... 200 Melanospora, - - . . 184 MeUxnotaenium, 313 Melasmia, - . - . 479 Meliola, .... 181 melleus, Agaricus (Armillaria), 455 melophthorum, Scolecotriclium, 508 menthae, Puccinia, 341 menyanthis, Cladochytrium, - 114 mercurialis, Caeoma, - 366, 367 419 ,, 8ynchytrium, 113 Merulius lacrymans, - 40 , 46 442 Mesochytrium, 110 mespili, Entomosporium, 481 ,, Morthiera, 210 ,, Stigmatea, 210 mespilinum, Oidium, 499 metulispora, Ascochyta, - 473 microcephala, Claviceps, 194 microchaeta, Vermicularia, - 471 Micrococcus, - - - 143, 531 535 Micropuccinia, - 356 I. INDEX OF PARASITES. 569 PAOK microsora, Puccinia, 355 microsperma, Passalora, 506 Microsphaera, 176 microsporum, Entyloma, 312 Microstroma, 497 Microtliyrium, 179 millefolii, Puccinia, 3(J1 minimus, Cephaleuros, 553 minor, Taphrina, - 147, 150, 153, 164 ,, Uromyces, - 338 minus, Cylindrosporium, 489 mirabiiis, Taphrina, - 147, 151-153 mirabilissima, Puccinia, - 340 mixta, Melampsora, 368 modestum, Bosti'ichonema, 501 moliniae, Neovossia, 311 ,, Puccinia, 349 Mulleri, Ustilago, - 298 mollis, Polyporus, - 448 Mollisia, . . . . 254 Mollisieae, ... - 253 Monipa, Helicol)asidium, 429 Monilia, .... 261, 497 monilioides, Oidium, - - 17 5,499 monoicum, Aecidium, 410 Monospora, .... 138 monotropae, Urocystis, - 319 niontana, Puccinia, 340 morbosa, Plowrightia, 231 niori, Bacterium, - 534 ,, Cladochytrium, 114 „ Phleospora, - 478 ,, Septogloeum, 496 ,, Sphaerulla, - - . 21 5, 478 moricola, Gibberella, 184 mors-uvae, Sphaerotheca, 173 Morthieri, Mollisia, 254 ,, Puccinia, 359 Mucedineae, .... 497 Mucor, ..... 4, 180 Muelleri, Uredo, - 420 niutila, Dothiora, - 249 Mycoidaceae, 552 Mycoidea, .... 552 Mycoidea, Cephaleuros, - 552 Mycomycetes,- 135 niyosotidis, Aecidium, - 411 „ Peronospora, 134 ,, Synciiytriuni, 111 PAGE myrtillina, Podosphaera, - - 175 Mystrosporium, .... 518 Myxomycetes, - - - 135, 522 Myxosporium, - - - - 486 N Naegelia, 326 Naevia piniperda, .... 238 nana, Taphrina, - 147, 149, 153, 161 napi, Pleospoi-a, .... 221 Napicladium, ..... 516 necans, Ovularia, - . . . 500 necator, Gloeosporium, - - - 483 necatrix, Dematophora, - - - 202 Nectria, 185 Nectriella, 184 Nectroideae, - . - . . 479 neglecta, Ustilago, .... 292 nelans, Ovularia, .... 261 nemoralis, Puccinia, - - - 349 Neovossia, 311 nepalense, Phragmidium, - - 363 neriella, Cercospora, - - - 515 nervisequium, Gloeosporium, - 229, 484 ,, Lophodermium, - 239 nicotianae, Ascochyta, - - - 473 nidus-avis, Gymnosporangium, - 403 Niesslii, Doassansia, - - - 323 ,, Sphaerotheca, - - - 174 nigra, Herpotrichia, - - - 199 nigricans, Claviceps, - - - 195 ,, Polyporus, .... 452 nigricantium, Macrosporium, - - 518 nigro-maculans, Septoria, - - 478 Niptera, 254 nitens, Caeoma, .... 419 nivea, Plasmopara, - - - 128 nobile, Macrosporium, - - - 518 Nostoc, 541, 546 nuda, Ustilago, .... 288 nympliaeae, Entyloma, - - - 313 nymphaeoides, Aecidium, - 351, 410 O obducens, Plasmopara, - - - 131 obliqua, Ovularia, .... 501 oblongata, Puccinia, - - - 354 oblongisporium, Peridermium, 375, 414 obscura, Puccinia, .... 352 570 I. INDEX (»F PARASITES. I'Ai;k PAGE obscurum, Polystignia, - . 190 oxycocci, Exobasidium, . - 426 obtusa, Puccinia, - :ui ,, Sclerotinia, - 259 occulta, Doassansia, - 824 oxyriae, Puccinia, . - 355 ,, Urocystis, - - 81.-) oxystoma, Valsa, - - 224 ochraceum, Polystigma, - 1<)0 Ochrospora, - . - . . 369 P octolooularo, Phragmidium, - - 363 pachydermus, Protoniyces, . - 141 oenotherae, Aecidiuni, - - 411 padi, Asteroma, - 470 ,, Puccinia, - 355 ,, Cylindrosporium, - - 489 officinalis, Polyporus, - 452 ,, Melampsora, - - 370 Oidium, . - . . 144, 175, 499 ,, Sclerotinia, . - 201 oleae, Bacillus, - 532 Paipalopsis, - . . . - 322 oleaginum, Cycloconium, - 506 paliformis, Puccinia, - 354 Oleina, - 138 pallescens, Thecaphora, . - 325 olida, Tilletia, - 310 pallidum, Chlorochytrium, - - 550 oligochaetuin, CoUetotrichum, - 486 pallidus, Uromyces, - 338 olivacea, Ustilago, - - 294 pallor, Ascochyta, - - 473 olivaceuni, Penicilliuni, - - ISO paludosa, Puccinia, - 351 Olpidiaceae, - - - - - 106 paudani, Melanconium, . - 188 Olpidiopsis, - - . . - 107 ,, Nectria, - - 188 Olpidium, .... - 100 panici-frumentacei, Ustilago, - - 292 omnivora, Phytophthora, 71 , S3, 117 ,, -leucophaei, ,, - 291 onobrychidis, Aecidium, - 410 ,, -miliacei, ,, - 289 ,, Diachora, - - 230 pannosa, Sphaerotheca, - 172, 499 Oomyces, .... - 1S4 papillatum, Phragmidium, - 363 Oomycetes, .... - 115 ,, Synchytrium, - 109 Oospoia, .... - 497 parasitica, Botrytis, - 500 Ophiobolus, .... - 222 ,, Mycoidea, - 552 orchidis, Caeoma, - 368, 419 , , Peronospora, . - 133 oreophila, Sclerotinia, - 259 ,, Septoria, - 475 oreoselini, Puccinia, - 353 ,, Tetramyxa, . - 529 orientale, Peridermium, - - 415 , , Trichosphaeria, 10, 196 ornamentals, Aecidium, - 410 parasiticum, Fusoma, - 504 oinithogali, Heterosporium, - - 510 parasiticus, Cephaleuros, - 552 Urocystis, - - 316 paridis, Puccinia, - - 349 ,, Uroniyces, - . 338 Parlatorei, Ustilago, - 298 ,, Ustilago, - 299 parnassiae, Aecidium, - 352 orobanches, Urocystis, - - 319 ,, Uromyces, - - 334 orobi, Uroniyces, - - 333 paspalus-dilatati, Ustilago, - 294 oryzae, Piricularia, - 503 Passalora, - 506 ,, Sclerotium, - 266 pastinacae, Cercosporella, - 503 „ Tilletia, - - 310 Patella, Heterosphaeria,- - 249 ,, Ustilaginoidea, - . 311 Pazschkei, Puccinia, - 359 ossifragi, Entyloina, - 313 Peckiana, Puccinia, 341, 419 ostryae, Taphrina, - 14S 150, 154 Peckii, Aecidium, - - 411 Ovularia, .... 261, 501) ,, P^xobasidium, - 427 oxyacanthae, Phleospora, - 478 ,, Peridermium, - 417 , , Podosphaera, - 174 pedicillata, Thelephora, - - 429 oxybaphi, Peronospora, - - 135 pedicularis, Aecidium, - 351, 410 I. INDEX OF PARASITES. 571 PAGE PAOE Pellicularia, - 181 phoenicis, Pestalozzia, - - 494 penicillariae, Tolyposporiuni, 306 Pholiota = Agaricus. penicillata, lloestelia, - 385, ;^89 391 Phoma, - - 465 Peiiieillium, - 3, 4 180 pliomoides, Gloeosjjoriuni, - - 483 pentastemonis, Aecidiiun, 411 Phragmidium, - 362 Peuzigi, Meliola, - 181 phragmitis, Puccinia, - 349 perdix, Thelephora, - J 5, 429 430 Phycomycetes, - 106 perennaus, Ustilago, 288 Phyllachora, - - 229 periclymeni, Aecidiuni, - 349, 409 Phyllactinia, - - 178 ,, Ascocliytu, - 473 Phyllobium dimorphum, - 551 ,, Leptothyriuiii, 479 Phyllosiphon arisari, - 553 Peridermiuni,- 374, 411 Phyllosticta, - - 463 Periphlegmatiuiii, - 551 Physalospora,- - 217 Perispoi-iaceae, 170 Physoderma, - - 114 Perisporieae, - 178 Phytaphysa Treubii, - 554 Perisporium, - 179 phyteumatum, Uromyce 5, - - 338 Peronospoia, - 132 Phytomyxa, - - 101, 524 Peronosporeao, 7, 13 115 Phytophthora, - 117 ,, remedies, 68 piceae, Chrysomyxa, - 380 perplexans, Puccinia, 349 ,, Peridermium, - 417 peisicae, Cercospora, 513 pic.ipes, Polyporus, - - 452 ,, Cercosj)orella, - 503 picridis, Entyloma, - 312 Phyllosticta, - 463 ,, Puccinia, - - 355 persiciiia, Tuberculina, - 327 Piggotia astroidea, - - 230 persistens, Puccinia, 349 Pilacreae, - 421 Persoiiii, Quaternaria, 226 pilificum, Synchytrium, - Ill Pestalozzia, - 491 pimpinellae, Puccinia, - 340 Pestalozzina, - 494 ,, Thecaphora - 325 petasitidis, Coleroa, 195 pinastrella, Phoma, - 468 Petersii, Aecidium, 410 pinastri, Lophodermium - 235 petroselini, Septoria, 476 pinguicolae, Ustilago, - 297 Pezicula (see Derniatea),- 253 piui, Brunchorstia, - 481 Peziza, - - - - 271 ,, Lachnella, - 272 Pezizeae, 253 ,, Peridermium, - 411,415 Phacidiaceae, - 241 ,, Trametes, - 38, 453 phacidioides, Sphaeroneiua, 255 pinicola, Hypoderma, - 234 Pliacidiuin, - 241, 255 ,, Polyporus, - 449 Phaeophila, 551 pinitorquum, Caeoma, - 364 Phaeophyceae, 554 pinophihim, Apiosporiun 1, - 181 Phakospoia, - 361 piperatum, Gloeosporiun 1, - - 483 plialaiidis, Puccinia, 349 Piptocephalis, - 11 phaseoli, Phytophthora, - 122 pirata, Roestelia, - - 391,402 ,, Uromyces, 334 piricola, Septoria, - - 476 phaseolina, Phyllosticta, 464 Piricularia, - - 503 phillyreae, Aecidium, - 410 piriforme, Peridermium, - 414 Uredo, - 420 piriformis, Mucor, - - 180 phlei-pratensis, Puccinia, 348 pirina, Phyllosticta, - 463 Plileospora, 478 pirinum, Fusicladium, - 218, 507 plioenicis, Graphiola, 325 , , Venturia, - 218 I. INDEX OF PARASITES. pirolae, Chrysomyxa, ,, Melampsora, pisana, Anthostomella, pisi, Ascochyta, ,, Cladosporium, ,, Uromyces, pitliya, riionia, pityophila, Cucurbitaria Placosphaeria, plantaginis, Aecidium, ,, Kaimilaria, riasiiiodiophora, Plasmopara, - platani, Fenestella, ,, Fusarium, - Pleolpidiuiii, - Pleonectria, - Pleospora, Pleosporeae, - Pleotrachelus, Plowrightia, - Plowrightii, Periderniium pluinbea, Ustilago, poae, Uromyces, poarum, Puccinia, - podagrariae, Actinonema, ,, Phyllachora, Podiosoma juniperi, Podocapsa, podophylli, Pliyllosticta, Podosphaera, - poleiDonii, Aecidium, polygon!, Peronospora, - ,, Puccinia, ,, Uromyces, polygonorum, Stigniatea, polymorpha, Bulgaria, - polypodii, Sphaerella, - ,, Uredo, - Polyporeae, - - - 5 ,, action on starcli, - ,, remedies, Polyporus, . . . . polyspora, Taphrina, 148, 151 Polystictis, - . . . Polystigma, - - - . Polythrincium, populi, Marsonia, - ,, Septoria, - - 380 - 370 - 22G - 472 - 510 - 334 - 466 - 210 - 471 - 411 - 502 - 524 - 127 - 229 - 184 -. 107 - 184 221,511 - 217 ;, 28, 107 - 230 376, 414 - 336 - 348 - 474 - 229 - 465 - 138 - 465 - 174 - 411 - 135 - 355 - 334 - 211 - 253 - 215 - 420 6, 17, 433 - 34 70,72 - 433 154, 168 - 452 7, 189 - 229 - 491 - 478 populina, Didymosphaeria, - 218, ,, Melampsora, - Poria = Polyporus. porri, Puccinia, portulacae, Cystopus, postuma, Peziza, - potentillae, Coleroa, ,, Magnusiella, , , Marsonia, , , Peronospora, ,, Phragmidium, ,, Taphrina, - praecox. Fusicladium, pratensis, Ramularia, prenanthis, Puccinia, primulae, Puccinia, ,, Uromyces, primulana, Ovularia, primulicola, Phyllosticta, ,, Tuburcinia, princeps, Calosphaeria, - Pringsheimiana, Puccinia, proeminens, Uromyces, - profusa, Aglaospora, profiisum, Septogloeum, proserpinacae, Aecidium, Prosti, Puccinia, - Protobasidiomycetes, Protomyces, - - - - 7, 31 pruinosa, Ramularia, ,, Sphaerotheca, prunastri, Dermatella, - ,, Uncinula, prunellae, Aecidium, , , Asteroma, pruni, Puccinia, ,, Taphrina, - - 147, If prunicola, Didymaria, - ,, Phyllosticta, - pseudocerasus, Kxoascus, pseudocolumnare, Aecidium, Pseudocommis, pseudoigniarius, Polyporus, Pseudolpidium, Pseudopeziza, Pseudophacidieae, - pseudoplatani, Septoria, - Pseudorhytisma, - pseudotuberosa, Ciboria, 249 367 I. INDEX OF PARASITES. 573 pseiulotuberosa, Sclerotinia, psoraleae, Aecidiuni, ptarmicae, Leptothyrium, ,, Schizothyriiiin, pteleae, Aecidium, - pteridis, Cryptomyces, - ,, Fusidium, - ,, Uredinopsis, Puocinia, Pucciniosira, - Pucciniopsis, - pulchella, Ovularia, pulicaris, Gibberella, puli)Osinn, Cladochytiium, pulsatillae, Coleosporium, pulverulenta, Puccinia, - punctata, Melasmia, punctatum, Aecidium, ,, Rhytisina, - ,, Synchytriiini, piinctiforme, Leptostroma, , , Nostoc, punctifoi-mis, Phyllachora, ininctuii), Synchytriuin, - pupurasoens, Taphrina, - purpurea, Claviceps, ,, Puccinia, , , Urocystis, pusilla, Claviceps, - ,, Plasmopara, pustulata, Buiillia, - ,, Melampsora, - putrefacieiis, Sporidesniiuni pychroa, Calonectria, Pycnis, - - - - Pycnochytiiuin, pygmaea, Plasmopara, - pymaea, Ravenelia, Pyrenochaeta, Pyrenomycetes, Pyroctonum, - Pythium, Q quadi-itidum, Aecidium, - Quaternaria, - quercina, Clithris, - , , Colpoma, ,, Rosellinia, 147, 1 7, PAGE PAGE - 270 fiueicinum, Capuodiuin, - - 181 - 410 quercus, Maisonia, - 491 - 242 Uredo, - - 420 - 242 quercus-ilicis, Gnomonia, - 223 - 410 quinqueloculare, Phragmidium, - 363 - 24S - 248 R - 420 Rabenhorstiana, Ustilago, - 291 - 339 raceraosus, Mucor, - - 180 - 404 radiatus, Polyporus, - 452 - 356 radiciperda, Ti'ametes, - - 450 - 500 radicola, Bacterium, - 101 - 184 radicolus, Protomyces, - - 141 - 114 radiosum, Asteroma, - 474 - 377 Ramularia, - 501 - 341 ramulosum, Macrosporium, - 518 - 480 ranunculacearum, Aecidium, - - 409 23, 409 ranunculi, Entyloma, - 312 - 244 Fabraea, - 255 - 112 ,, Stigmatea, - - 210 - 480 Rauwenhoffii, Tilletia, - - 310 - 541 Ravenelia, - 403 - 241 Ravenelii, Peridermium, - 416 - Ill Reessia, . - - - - 107 51, 153 Reiliana, Ustilago, - - 282 29, 191 repandum, Pliacidium, - - 241 - 353 repentis, Melampsora, - - 368 - 319 resedae, Cercospora, - 515 - 195 rhamni, Aecidiuni, - - 346 - 130 rhinanthi, Sclerotium, - - 266 - 322 Rhizina, - - - - - 272 - 370 rhizipes, Taphrina, - 1-^ 7, 151, 152 121, 465 fihizobium, - 101 - 184 Rhizoctonia, - 201, 274 - 226 rhizoides, Sclerotium, - - 266 - 109 rhizophora, Taphrina, 147, If )0, 152, 157 - 130 rhodiolae, Puccinia, - 359 - 403 rhododendri, Apiosporium, - 181 - 470 ,, Chrysomyxa, - 377 - 183 ,, Exobasidium, - 427 - 114 ,, Gloeosporium, - 485 4, 116 ,, Hendersonia, - 475 Sclerotinia, - 262 lUiodomyces, - - 143 - 409 Rhodophyceae, - 555 - 226 Rhytisma, - 71, 242 - 248 rhytismoides, Dyscomycopsis - 245 - 248 ribesia, Scleroderris, - 251 - 200 ribesii, Gaeoma, - 368 571 I. INDEX OF PARASITES. ribicola, Plasinopara, - 131 ribicoluni, Ci-oiiartium, - - 382 ribis, Gloeosporiuni, - 483 ,, Polyporus, - - 452 „ Pucciiiia, - 3r)<) ,, Septoria, ■ 476, 515 robertiani, .Stigmatea, - - 210 robiniae, Dothiorella, - 229 Robinsouiana, Taphrina, 150, 152 rosae, Actinoneina, - 474 ,, Dicoccum, - - 506 ,, Gloeosporium, - 483 ,, Marsonia, - 506 ,, Septoria, - 478 rosae-alpinae, Phragmiclium, - 362 rosaecola, Cercospora, - - 515 rosea, Ovularia, - 501 Rosellinia, - 200 rostratum, Urobasidiuin, - 427 Rostrupia, - 354 Rostrupiana, Taphrina, 147, 1 51, 152, 156 Rostrupii, Peridernuum, - 377 Rousseauaua, Fabraea, - - 255 Rouselliana, Nectria, - 188 rubefaciens, Puccinia, - - 359 rubellum, Aecidium, - 349 rubescens, Ascoidea, - 141 rubi, Exosporium, - - 195 ,, Phragmidium, - 363 ,, Septoria, - 476 ,, -idaei, Phragmidium, - 363 ,, ,, Pyrenochaeta, - 470 ,, -miniatum, Phi'agmidiun 1, - 363 rubigo-vera, Pueciuia, - - 347 rubra, Endosphaera, - 551 rubrociiictum, Synchytrium, - - 112 rubrum, Polystigma, - 189 rufibasis, Ramularia, - 502 rufomaculans, Ramularia, - 502 rumicis, Uromyces, - 337 ,, Venturia, - - 218 rumicis-scutati, Puccinia, - 355 ruscicola, Phyllosticta, - - 465 S sabinae, Gymnosporangium, - 74, 395 sacchari, Trichosphaeria, - 198 ,, Ustilago, - - 284 ,, -ciliaris, Ustilago, - - 284 sacchariuum, Cyliiidrosporium, Saccharomyces, Sadebeckianum, Pythium, Sadebeckii, Taphi-ina, 148, 150, sagittariae, Doassaiisia, - salicina, Melampsora, ,, Melasmia, - salicinum, Capnodium, - ,, Didymosporium, ,, Rhytisma, salicinus, Polyporus, salicis, Uncinula, - salicis-capreae, Melampsora, salicorniae, Uromyces, - sambuci, Aecidium, , , Phyllosticta, - sanguineum, Synchytrium, sanguinoleuta, Plioma, - sanguisorbae, Phragmidium, saniculae, Puccinia, saponariae, Soro&porium, Saprolegniaceae, sarcinaeformae, Macrosporium sarcinula, Macrosporium, saxifragae, Caeoma, ,, Puccinia, scabies, Oospora, scabiosae, Ascochyta, ,, Ustilago, scelerata, Ovularia,- Schachtii, Peronospora, - Schiedermayeri, Hydnum, Schinzia, Schinzianum, Exobasidium, Schizomycetes, Schizonella, - Schizospora, - Schizothyrium, Schleideni, Peronospora, Schneideri, Puccinia, Schoeleriana, Puccinia, • Schroederi, Puccinia, Schroeteri, Uromyces, - Schroeteria, - Schroeteriaster, Schweinfurthiana, Ustilago, Schweinfurthii, Aecidium, Schweinitzii, Polyporus,- „ Ustilago, - PAGE - 489 8, 143 - 117 154, 168 32 I. INDEX OF PARASITES. 575 PAOE scillae, Puccinia, - 359 scillamm, Uromyces, - 338 scirpi, Puccinia, - 352 Scleroderris, - - 250 Sclerospora, - - 131 Sclerotiuia, - 3, 7, 16, 29, 256 sclerotiorum, Peziza, - 263 ,, Sclerotinia, - 2,4,263 Sclerotium, - 266, 431, 500 Scolecotrichum, - 508 scorzonerae, Ustilago, - - 290 Scotiiiosphaera parailoxa, - 550 Scribnerianuin, ClaJosporium, - 511 scrophulariae, Uromyces, - 338 scutellatus, Uromyces, - - 336 Scytonema, - 541 secales, Bacillus, - - 535 secalis, Tilletia, - 310 ,, Ustilago, - 289 sedi, Endophyllum, - 404 ,, Puccinia, - 359 ,, Septoria, - 478 Selinia, - - - - - 184 seminum, Ustilago, - 297 sempervivi, Eudophyllum, - 13, 404 senecionis, Coleosporium, - 374 , , Ovulaiia, - 500 ,, Puccinia, - 356 sentina, .Sphaerella, - 216 separata, Tilletia, - - 310 septentrionalis, Puccinia, - 352 Septocylindrium, - - 505 Septogloeum, - - 495 Septoria, - 475 Septosporium, - 518 serotiiuim, Entyloma, - 312 sesleriae, Puccinia, - - 349 Tilletia, - - 310 sessilis, Puccinia, - - 349 setariae, Ustilago, - - 291 ,, Ustilaginoidea, - - 311 setosum, Ceratophorum, - - 511 setulosa, Claviceps,- - 195 Sherardiana, Puccinia, - - 360 sii latifolii, Aecidium, - - - 336 silenes, Puccinia, - - 340 ,, Uromyces, - - - 334 simplex, Puccinia, • - 347 simulans, Olpidium, - 107 singularis, Puccinia, Sistotrema, sistotremoides, Polyporus, Slime-fungi, - smilacis, Aecidium, - smyrnii, Puccinia, - solani, Alternaria, - ,, Hypnochus, - ,, Macrosporium, ,, Phoma, ,, Rhizoctonia, ,, Schinzia (Entorrhiza), soldanellae, Puccinia, solidaginis, Uromyces, - Sommerfeltii, Aecidium, - sonchi, Coleosporium, ,, Puccinia, Soraueri, Peridermium, - Soraueriana, Pestalozzina, sorbi, Cucurbitaria, ,, Melampsora,- ,, Phoma, - sordida, Peronospoi'a, sorghi. Bacillus, ,, Cintractia, - ,, ilndothlaspis, ,, Fusicladium, ,, Puccinia, - ,, Uredo, ,, Ustilago, - Sorosphaera, - sorosporioides, Urocystis, Sorosporium, - sparsa, Melampsora, ,, Peronospora, sparsus, Uromyces, - speciosum, Gymnosporangium ,, Phragmidium spergulae, Puccinia, Sphaceloma, - Sphacelotheca, Sphaerella, Sphaerelloideae, Sphaeriaceae, - Sphaerioideae, sphaerogena, Ustilago, sphaeroidea, Dothidea, ,, Ovularia, sphaeroides, Dothiora, I'AOK 358 433 448 522 411 356 517 428 517 468 134 534 302 302 508 353 420 284 530 317 325 370 133 337 403 362 361 467 302 211 210 184, 195 463 291 230 501 218, 249 576 I. INDEX OF PARASITES. Sphaeroneina, - Sphaerophragmiuni, Sphaeropsideae, Sphaeropsis, - sphaeropsoidea, Phyllosticta, Sphaerostilbe, - Sphaerotheca, - sphagni, Tilletia, - spinaciae, CoUetotrichuni spinificis, Ustilago, - spinulosus, Cystopus, spiralis, Uncinula, - spissa, Didymaria, - splendens, Aecidium, Sporidesmium, Sporodesniium, spuineus, Polyporus, spurium, Sphaeroneina, squamosus, Polyporus, squarrosus, Agaricus, stachydis, Puccinia, ,, Septoria, Stagonospora, - Stahlii, Peridermium, stellariae, Syuchytrium, Stemphyliuni, - Stereum,- stictica, Pestalozzia, stictoides, Leptosphaeria, Stigmatea, Stilbeae, - - - stulonifer, Mucor, - Stomatochytrium, - straniinis, Puccinia, Straussii, Venturia, Streblonemopsis irritans striaeformis, Puccinia, striatus, Uromyces,- Strickeria, striiformis, Tilletia, strobi, Peridermium, ,, Phoma, strobicola, Hypoderma, strobilinum, Aecidium, struthiopteris, Uredinopsis, Stysanus, suaveolens, Puccinia, ,, Trametes, suljcorticium, Piiraginidium 371 TACK 4()9 3(U 463 472 464 184 171 310 487 299 127 176 501 - 410 221, 511 517 452 253 443 462 356 478 475 414 111 182 429 494 221 210 519 180 550 347 218 555 347 336 204 310 382, 415 468 233 407 420 519 353 455 362 PAGE subiiiclusa, Cintractia, - - 302 ,, Ustilago, - 301 subtecta, Leptosphaeria, - . 221 subtilis, Coleroa, - - 195 succisae, Synchytrium, - - 110 ,, Ustilago, - - 296 sutfocata, Pestalozzia, - 494 suffulta, Phyllactinia, - 178 sulcigena, Hypodermella, - 234 sulphureus, Polyporus, - 6,437 sylvatica, Puccinia, - 351 symmetricum, Rhytisma, - 246 symphyti, Uredo, - - 420 symploci, Exobasidium, - 427 synantherearum, Coleosporium, - 377 Syncephalis, - - - - 11,28 Synchytriaceae, - 107 Synchytrium, - 108 syringae, Ovularia, - 501 T tabaci, Oidium, - 499 ,, Phyllosticta, 464 tabifica, Phyllosticta (Sphaerella), 464 taleola, Aglaospora, 226 ,, Diaporthe, - - 226 tanaceti, Puccinia, - ■ 355 Taphria = Taphrina, 146 Taphrina, - - .-7, 29, 146, 148 Taphrinopsis, - - - - 148 taraxaci, Puccinia, 353 Synchytrium, - - 22, 108 taxi, Capnodium, - 181 ,, Phoma, ... - 468 ,, Sphaerella, 215 tenuistipes, Puccinia, 351 Tepperianus, Uromyces, 338 terebinthi, Uromyces, - 337 teres, Helminthosporium, 512 Tetramyxa, .... 529 thalictri, Aecidium, 349 Entyloma, 312 Puccinia, 358 Thecaphora, .... 324 Thecopsora, .... 370 thelebola, Aglaospora, - 226 ,, Melanconium, 226 Thelephora, .... 429 thesiL Puccinia, 341 I. INDEX OF PARASITES. 571 P;'.OE PAGE Thielavia, - 182 trigonellae, Uromyces, - - 337 Thielaviopsis, - 183 Triphragraiuni, . 361 thlaspeos, Puccinia, - 361 tritici, Leptosphaeria, - - 221 TiUetia, 310 „ Tilletia, - 306 tiliae, Actinonema, - 474 ,, Ustilago, - 288 ,, Phyllosticta, 464 troUii, Puccinia, - 356 Tilletia, .... 46,68 30(; tropaeoli, Pleospora, - 221 Tilletieae, 275 Tuberaceae, - - 183 Tolyposporium, 305 Tubercularieae, - 520 Tomentelleae, 423 tuberculatum, Phragmidium, - 362 tonnentillae, Phragmidium 363 tuberculatus, Uromyces, - 337 tortilis, Erysiphe, - 175 Tuberculina, . - 327 Torula, - - . - - 143 181 tuberosa, Sclerotinia, - 266 Toscjuinetii, Taphrina, 147, 150, 153 166 tuberum, Cladosporium, - 511 toxicodendri, Marsonia, - 491 Tubeufianuni, Cylindrosporium, - 488 Trabutiana, Ustilago, . 299 Tuburcinia, - 319 Trachyspora, - 337 Tuckeri, Erysiphe, - 176 tragopogonis, Cystopus, . 127 ,, Oidium, - 177, 499 ,, Puccinia, . 356 Tulasnei, I'amularia, - 214 ,, Ustilago, - . 296 Sphaerella, - - 509 Trailii, Puccinia, - 349 ,, Uncinula, - 178 ,, Thccaphora, 324 , , Ustilago, - 284 Trametes, - 450 453 tulipae, Puccinia, - - 359 Trematosphaeria circinans, 201 ,, Sclerotium, - 500 Treniellinae, - . 421 ,, Ustilago, - - 299 tremelloides, Gymnosporangium, - 389 turcicum, Helminthosporium, - 512 tremulae, Ascocliyta, - 473 turgida, Taphrina, 147, K 0, 152, 159 ,, Fusicladiuni, - 508 tussilaginis, Coleosporium, - 376 , , Melampsora, - - 364 367 typharum, Heterosporium, - 516 ,, Napicladium, - 218 typhina, Epichloe, - - 191 Trentepohlia endophytica, 551 Typhula, - 431 Treubii, Ustilago, - - 30 299 ,, Phytaphysa, 554 u trichella, Verinicularia, - . 471 Ulci, Urocystis, - 316 trichophora, Ustilago, - . 291 ,, Ustilago, . 299 Trichospliaeria, - 61 195 uliginosa, Puccinia, . 351 Trichosphaerieae, - 195 ulmariae, Ramularia, - 502 Trichospora, . 403 , , Stysanus, - 519 tridactyla, Podosphaera, . 174 ,, Triphragmium, - 361 trientalis, Tuburcinia, - 319 ulmarius, Polyporus, . 452 trifolii, Olpidium, - - 107 ulmi, Apiosporium, - 181 „ Phacidiuni, 255 ,, Aster om a. - 470 „ Phyllachora, . 229 „ Dothidella, - - 230 ,, Polythrincium, - 229 ,, Phleospora, - - 478 ,, Pseudopeziza, - 255 ,, Phyllachora, - - 496 ,, Synchytrium, - 107 109 ,, Pleospora, - 221 Uromyces, 333 ,, Septogloeum, - 496 trifoliorum, Peronospora, - 132 ,, Taphrina, - - 14 8, 149, 154 ,, Sclerotinia, - 265 ulmicolum, Ceratopliorum, . 512 2o 578 I. INDEX OK I'AKASITES. uinbcUiferanim, p]rysiphe, ,, Magniisiella, 148 umbilici, Puccinia, umbonatuiu, Rhytisma, Uncinula, undulata, Rliizina, - Ungeri, Didymaria, Ungerianum, Kntyloma, uniseptatuni, Dicoccum, Uredineae, - - 7, 13 ,, hetei'oecism, Uredinopsis, - Uredo-forins, - Ui'iuila, Sclorotinia, Urobasidiuin, - Urocystis, Uromyces, Urophlyctis, - Uropyxis, urticae, Peronospora, ,, Ramiilaria, ,, Rhytisma, - ,, Septorig, - , Ustilagineae, 7, 13, 16, 5l, ,, infection, ,, remedies, Ustilaginoidea, Ustilago, utriculosa, Ustilago, iivicola, PJioma, vaccinii, Exobasidium, - ,, Gibbera, - ,, Melampsora, ,, Sclerotinia, ,, Synchytrium, - vagans, Fumago, - Vaillantii, Ustilago, valantiae, Puccinia, Valerianae, Puccinia, ,, Uromyces, Valsa, - - . . Valseae, - - - . valsispora, Dendrophoma, vanillae, Calospora, ,, Gloeosporium, - vaporarius, Polyporus, - variabile, Heterosporium, 28, 47. - 175 1,11, 154 3G1 246 176 272 501 312 506 48, 328 45, 51 141, 420 420 256 427 314 333 113 361 135 502 246 478 47, 275 52,54 65 311 276 298 21G 423 204 370 256 109 181 299 301 356 334 224 223 469 485 485 442 516 variabilis, Ramularia, varius, Exoascus, - vasinfectum, Fusarium, vastatrix, Hemileia, venetum, Gloeosporium, Venturia, veratri, Puccinia, - ,, Uromyces, Vermicularia, vermiculariaeformis, Venturia, vernalis, Endomyces, ,, Melampsora, veronicae, Ovularia, ,, Puccinia, ,, Sorosphaera, ,, Stysanus, veronicarum, Puccinia, verruculosum, Entyloma, Vialae, Uredo, viburni, Plasmopara, ,, Ramularia, viciae, Ascochyta, - ,, Peronospora, ,, Phyllosticta, vincae, Puccinia, - vinosa, Ustilago, - violacea, Rhizoctonia, ,, Ustilago, - \'iolaceum, Phragmidium violae, Cercospora, - ,, Gloeosporium, ,, Peronospora, ,, Phyllosticta, ,, Puccinia, ,, Urocystis, - - 16, 21 virgaureae, Puccinia, virginica, Taphrina, - 148 virgultorum, Dothidea, viride, Chlorochytrium viridis, Cyliudrosporium vitellinae, Melampsora viticola, Cercospora, ,, Plasmopara, viticolum, Cladochytrium ,, Cladosporium, vitigena, Leptosjjhaeria, vitis, Aureobasidium, ,, Plasmodiophora, - ,, Sphaerella, - 340 31, 317 359 150, 154 230 550 489 368 513 128 114 510 221 428 528 215 I. INDEX OF PARASITES. 579 vitis, Uredo, - Volkensii, Ravenelia, Volutella, Vrieseana, Ustilago, Vuijkii, Ustilago, - vulgaris, Botrytis, - ,, Phyllosticta, vulpinae, Piiccinia, W \Varburgiana, EpichloiJ, - Warmingii, Exobasidiiim, Westendorpii, Thecaphora, Willkonimii, Dasyscypha, - 420 Willkommii, Pezlza^ - 403 Wiuteriana, Puccinia, - 520 Wittrockii, Eiitodernia - 299 - 294 X - 500 xauthoxyli, Aecidiiim, - 464 Xenodochus, - - 351 xylostei, Anthostoina, Z zonata. Tilletia. 191 Zopfia, - 427 Zopfiella, 325 I Zopfii, Puccinia 271 Zygomycetes, - PAGE 6, 20, 271 - 349 - 551 410 363 226 310 179 17S 341 114 11. GENERAL INDEX OF HOST-PLANTS, COMMON NAMES, Etc. PA(!K PAGE A Rhytisma, - 242, 244 Abies, Aecidium, 404, 409 Septogloeum, 495 Agariciis, 457, 461 Septoria, 478 Apiosporiuni, 181 Taphrina, 151-154, 168 Caeoma, 418 Uncinula, - 177, 178 Calyptospora, 372 AcMllea, Cystopus, - 127 Lophodermium, 239 Leptothyrium, 242 Nectria, - 185 Protomyces, - 141 Perideniiimn, 417 Puccinia, 361 Pestalozzia, - 493 Scliizothyriuiii, 242 Phonia, - 465 Synchytriuin, 113 Polyporus, 439, 442, 448, Aconitum, Puccinia, - 356 449 450 Urocystis, 316 Rhizina, 274 Acorus, Scleiotinia, - 270 Septocylindrium, - 505 Tramotes, 453 Actaea, Aecidiuni, 409 Trichosphacria, 196 Urocystis, 316 Abietineae, INIycorhiza 96 Adenostyles, Aecidiuni 348 Acacia, Aecidiuni, 410 Coleosporiuni, 377 Pavenelia, - 403 Niptera, - 254 Uromyces, 338 Puccinia, - 348 , 359 Acer, Cercospora, - 513 Uromyces, 337 Cylindrosporium, - 489 Adhesion-discs = appre 3- Dermatea, 253 soria. Dyscomycopsis, - 245 Adonis, Urocystis, - 317 Leptothyrium, - 479 Adoxa, Puccinia, 341 , 359 Melasmia, 24-2 ,480 Synchytriuin, 112 Nccti-ia, - - 185 Ustilago, 299 Oidium, - 499 Aecidium, Tuherculina , 327 Pestalozzia, - - 493 Aegopodium, Pezicula, - 253 Actinonema, - 474 Plileospora, - - 478 Caeoma, - 419 Phyllosticta, - 463 Phyllachora, - 229 Polyporus, 435 ,444 ,452 Protomyces, - 138 PAGE Puccinia, - - 359 Aesculus, Aecidium, - 410 Diplodia, - - 472 Nectria,- - - 185 Phyllosticta, - - 464 Polyporus, - - 444 Septoria, - - 478 Slime-flux, - - 143 Taphrina, - 151, 153 Aethusa, Puccinia, - 353 Agaricus, Endomyces, 141 Agave, Cladosporiuni, 509 Agrimonia, ]Melanipsora,370 Uredo, - - - 420 Agropyrum (see also Triticum ) Puccinia, - 345, 349 Ustilago, - - 293 Agrostemma, Taphrina, - 151, 154 Agrostis, Puccinia, 345-349 Tilletia, - - - 310 Ailantbus, Cercospora, 515 Aira, Entyloma, - 313 Puccinia, - - 345 Ustilago, - - 294 Ajuga, Phyllobium, - 551 Albizzia, Uromyces, - 338 Alchemilla, Bostrichonema, - 501 Coleroa, - - - 195 Uromyces, - - 337 Alder, black = Alnus glutinosa. II. GENERAL INDEX. 581 Alder, wlute=Alnus incaiia. Aletris, Physalospora, "J IS Algae, Chlorocystis, - 550 Entoderm a, - - 551 Entonema, - - 555 Harveyella, - - 555 Olpidium, - - 107 Periphlegmatiuni, - 551 Phaeophila, - - 551 Pythiuni, - - 117 Strebloueniopsis, - 555 ,, blue-green, - - 541 ,, pathogenic, 539, 547 Alisma, Cladochytriuni, 114 Doassansia, - - .323 Pseudopeziza,- - "255 Allium, Aecidium, - 349 Bacteriosis, - - 539 Caeoma, - - 367, 419 Cladocliytrium, - 114 Macrosporium, - 518 Peronospora, - - 132 Puccinia, - .341, 355 Rhizoctonia, - - • 202 Sclerotinia, - - 266 Urocystis, - - 316 Uromyces, - 337, 33S Vermicularia, - 471 Almond (see Amygdalus) Alnus, Corticium, - 452 Fraukia, - - 101 Leptothyrium, - 479 Microsphaera, - 176 Mycodouiatia, - 99 Mycorhiza, - - 99 Ovularia, - - 501 Passalora, - - 500 Polyporus, 433, 439, 452 Sclerotinia - - 262 Stigmatea, - - 211 Taphrina, 150, 157, 158, lOfJ, 168 Valsa, - - - 224 Alopecurus, Pestaluzzina, - - 495 Puccinia, 345, 340, 349 Tilletia, - - - 310 Alpine-rose (see Kho- dodeudron) PAGE Alsineae, Puccinia, - 301 Althaea, Cercospora, - 515 CoUetotrichum, - 487 Phoma, - - - 469 Phyllosticta, - - 464 Puccinia, - - 360 Amarantaceae, Cystopus, - - 127 Amelanchier, Fusicladium, - - 507 Gymnosporangium, 385, 391, 401, 402, 403 Oidium, - - - 499 Podosphaera, - - 173 I'vocstelia, 385, 391, 402 Ampelopsis, Cercospora, 515 AmpMcarpaea, Synchytrium, - 109 Amygdalus (see also Prunus) Ascospora, - - 211 Cercospora, - - 513 Gloeasporium, - 483 Polystigma, - - 189 Taphrina, 150, 153, 165 Anbury, - - - 524 Anchusa, Aecidium, - .347 Andromeda, Coleroa, 195 Exobasidium, 426, 427 Rhytisma, - - 246 Stigmatea, - - 211 Andropogon, Claviceps, 195 Puccinia, - 345, 354 Tilletia,- - - 310 Ustilago, - - 292 Androsace, Peronospora, - - 134 Anemone, Aecidium, 23, 409 Coleosporium, - 377 Protomyces, - - 141 Puccinia, 356, 358, 300 Sclerotinia, - - 200 Septoria, - - 478 Synchytrium,- - 112 Urocystis, - - 316 Anethum, Puccinia, - 353 Heterosphaeria, - 249 Angelica, Fusicladium, 508 Puccinia, - - 340 PAGE Anthoceros, Nostoc, - 546 Anthoxanthum, Puccinia, - 345, 354 Tilletia, - - - 310 Anthracnose, Blackberry, - - 483 Cotton, - - - 487 Privet, - - - 485 Raspberry, - - 483 Vine, - - - 467 Anthriscus, Plasmopara, 128 Puccinia, - - 340 Anthyllis, Uromyces, 337 Apium, Cercospora, - 514 Entyloma, - - 312 Macrosporium, - 518 Phyllosticta, - - 464 Puccinia, - 353, 355 Septoria, - - 477 Apocynum, Aecidium, 411 Septogloeum, - - 496 Apple (see Pyrus Mains) -blight, - - - 531 -rot, - - - 482 powdery mildew, - 174 Appressoria, - - 9 Apricot (see Prunus) Aquilegia, Aecidium, - .349, 409 Arabis, Aecidium, - 410 Puccinia, - 359, 361 Ustilago, - - 297 Aralia, Tripliragmium, 362 Arctium, Aecidium, - 351 Arctostaphylos, Exobasidium,- - 427 Melampsora, - - 370 Arisarum, Phyllosiphon,553 Aristida, Ustilago, - 294 AristolocMa, Puccinia, 341 Armeria, Uromyces, - 334 Armoracia, Ascochyta, 473 Alternaria, - - 518 Cercospora, - - 514 Cystopus, - - 126 Ovularia, - - 500 Septoria, - - 477 Arnica, Entyloma, - 312 Arnoseris, Entyloma,- 312 582 ir. OENKRAL INDEX. PAGE PAGK Aronia, Pliyllosticta, - 465 (iymnosporangium. 391 Atropliy, - - 22, 26 Roestelia, 392 Aubernage, - 202 ,534 Arrhenatherum, Autoecism, 45 Exobasidiuni. 427 Avena, Cladosporium, 509 Puccinia, 345 Erysiphe, 175 Tilletia, - 310 Fusarium, 512 Urocystis, 316 Fusicladium, - 508 Ustilago, 288 Helminthosporium, 512 Arrowroot (see Maranta) Phoma, - 467 Artemisia, Peronospora ,134 Puccinia, 345, 346 ,348 I'lucinia, 361 Scolecotriclium, 508 Artichoke (see C'ynara) Septoria, 477 „ Jerusalem (see Uromyces, 336 Helianthus] Ustilago, - 284 287 Arum, Aecidium, 349 410 Azolla, Anabaena, 545 Caeoma, - 419 Ustilago, 299 B Arundinaria, Ustilago, 293 Bacterial diseases or Arundinella, Ustilago, 294 Bacteriosis, - 530 Asarum, Puccinia, 32 359 Bacteroids, 102 Asclepias, Aecidium, - 411 Bambusa, Neovossia, 311 Asli (see Fraxinus ex- Puccinia, 354 celsior) Barbarea, Aecidium, 409 Ash-canker, 533 Barberry (see Berberis Asparagus, Cercospora 514 Barley (see Hordeum) Puccinia, 341 Bartsia, Coleosporium, 376 Rhizoctonia, - 202 Batatas, Ceratocystis, 469 Aspen (see Populus Cladosporium, 511 tremula) Cystopus, 127 Asperula, Phacidium, 241 Nectria, 189 Puccinia, - 341 353 Phyllosticta, - 464 Aspidistra, Ascochyta, 473 Rhizoctonia, - 202 Aspidium ^ „ Asplenium/^^*^^^^"^^) (see also Ipomoea) Bean (see Vicia) Aster, Aecidium, 3oI, 411 ,, Kidney (see Phaseolus) Basidiophora, 127 Beech (see Fagus) Puccinia, 361 Beet-root and Sugar Beet Astragalus, Didymaria 501 (see Beta) Miciosphaeia, 176 Beet, heart rot, - 464 Polystigma, - 190 „ -scab, - 497 537 Thecaphora, - 324 Bellidiastrum, Uromyces, 337 Aecidium, 351 Astrantia, Fabraea, - 255 Entyloma, 312 Puccinia, 359 Puccinia, 359 Athamantha, Puccinia, 340 Bellis, Aecidium, 352 Atragene, Puccinia, - 358 Berberis, Aecidium, 341 409 Urocystis, 316 Didymosphaeria, - 218 Atriplex,Cladochytrium ,114 Melasmia, 479 PAOE Microsphaera, - 176 Puccinia, - - 340 Beta, Bacteria, - - 537 Cercospora, - - 514 Entyloma, - - 313 Oospora, - - 497 Peronospora, - 132 Phonui, - - 468 Phyllosticta, - - 464 Pythium, - - 116 Rhizoctonia, - - 202 Sclerotinia, - - 264 Sporidesmium, - 221 Uromyces, - - 334 Betonica, Puccinia, - 359 Ustilago, - - 298 Betula, Cladosporium, 511 Doth idea, - - 230 Dothidella, - - 230 Hormomyia, - - 262 Melampsora, - 366, 367 Microsphaera, - 176 Myxosporium, - 486 Phyllactinia, - - 178 Polyporus, 446, 449-452 Sclerotinia, - - 261 Slime-flux, - - 143 Taphrina, 149-154, 159-161, 167 Twig-galls, - - 532 Uncinula, - - 178 Bilberry (see Vaccinium Myrtillus) Birch (see Betula alba, etc.) Bitter-rot,- - - 482 Black-knot, - - 231 ,, -rot, Vine, 216, 484 ,, -rust, - 341, 419 ,, -shank, - - 469 Bladder-plums, - - 155 Blanc des Racines, - 202 Blight, a common name for diseases Boragineae, Erysiphe, 175 Puccinia, - 347, 348 Borage, Entyloma, - 312 Bordeaux mixture, 69, 172 Bouillie-Bordclaise, - 69 Bouteloua, Ustilago, 299 II. GENERAL INDEX. 583 PAGE PAGE PAGE Brachypodium, Cacalia, Coleosporiuni, 377 Tilletia, 310 PiKuinia. - 346, 304 Uromyces, 337 Tolyposporiuin, 306 TilK'tia, 310 Cactus, Phytophthora, lis Ustilago, - 27 294 Uroiiiyces, 336 Caeoma, Tuberculina, 327 Carlina, I'uccinia, 353 Bramble (see Paibus) Calamagrostis, Carnation (see Diantlius) Brand, Vine, 4S4 Puccinia, 346 bacteriosis, - 532 Brands (see Ustilagineae) Sclerotium, - 266 fairy ring spot. 516 Brassica, Ascochyta, 473 Tilletia, 310 rosette, - 522 Altei-naria, 518 Ustilago, 293 rust. 336 Ccrcospora, - rAA Calathea, Cephalenros 553 spot. 477 Cystopus, 126 Calcium oxalate and fungi, Carpinus, Dennatea, 253 Macrosporiuni, 518 35 Fusicladium, - 508 Olpidium, 107 Calendula, Entylonia, 312 Cnomoniella, - 223 Peronospora, - 133 Caltha, Fabraea, 255 Mamiania, 223 Plasniodiophora, 524 Pseudopeziza, 255 Melampsora, - 370 Pleospora, 221 Puccinia, 341 Pezicula, 253 Sclerotinia, - 264 Camellia, Cephaleuros, 552 Phyllactinia, - 178 Spliaerella, 215 Coryneum, 491 Polyporus, - 447 452 Sporidesmium, 221 Meliola, 1S2 Slime-flux, 143 Briza, Puccinia, 345 Pestalozzia, - 494 Taphiina, 150-154 , 162 Tillctia, 310 Vermicularia, 471 Carrot (see Daucus) Bromus, Exobasidiun 1, 427 Campanula, Carthamus, Puccinia, 355 Puccinia, - 34 5, 347 Coleosporiuni, 377 Carum, Cladocliytrium 114 Spliaerella, - 215 Marsonia, 491 Puccinia, 356 Tilletia, 310 Puccinia, 359 Carya, Fusicladium, - 508 Urocystis, 316 Cankers (see under Hosts) Ramularia, - 502 Ustilago, - 29 2, 293 Nectria, Aecidium, etc. Cassandra, Brown -rot, 497 Cannabis, Exobasidiuin, 427 Brown -rust. 347 Dendrophoma, 469 Castanea, Diplodina, - 474 Briinissure, - 1 ] 4, 528 Peziza, - 265 Pestalozzia, - 494 Brusone, Pvice, - - 266 Septoria, 477 Phyllosticta, - 464 Brussoiie, Vine, - 484 Caper = Capparis spinosa Polyporus, 4.39 Bryzopyrum, Puccini a, 345 Cercospora, - 515 Septoria, 478 Buckwheat (seeFagop yrum) Cystopus, 126 Slime-flux, 143 Buils, premature, - 20 Capsella, Cystopus, - 126 Urocystis, 319 Bulb-lxicteriosis, - 538 Peronospora, - 133 Castration of flowers, 27 Bunt (see Tilletia) Plasniodiophora, - 524 Catalpa, Macrospo- Butomus, Capsicum, rium, - 518 Chulochytrium, - 113 (Jloeosporium, 483 Ceanothus, Aecidium, 411 Doassansia, - - 323 Caragana, Uromyces, 3.37 Cedar-apples, - 402 Buxus, Lacstadia, . 217 Carduus, Cedrus, Periderinium, 417 Leptostronia, - - 480 Puccinia, .340, 35.1 , 359 Celery (see Apium) Nectria, - 188 Thecaphora, - 324 Cell-contents and fung i, 31 Phonia, - - 468 Ustilago, 296 Cell -sap and fungi, - 33 Phyllosticta, - - 464 Carex, Cintractia, 302 Cell-walls and fungi, 36 Puccinia, - 361 Leptostroma, 480 Cellulose-destroying fungi, Phyllachora, - 229 .35, 38 c Puccinia, 349-3.") , 355 Celtis, Ramularia, 502 Cabbage (see Brassic 1) Schizonella, - 305 , Taphrina, - 149, 153 584 II. GKNEUAL INDEX. I'AOE l'A(!E PAGE Cenchrus, Cherry, Bird (see 1 'runus Dicoccum, 506 ToIypDsporium, 30() Padus) Clover (see Trifolium) Centaurea, Chervil (see Anthriscus) Clover-rust, 333 Aucidium, - 351 , 409 Chestnut, horse see Club-root, - 524 Piiccinia, - 340 , 353 Aesculus) Cochlearia, Centranthus, Puccinia 356 Chestnut, sweet see Alternaria, 518 Cephalantlius, Castanea) Cystopus, 126 Aocidiiun, 411 Chives (see Allium) Ovularia, 500 Cerastium, Aecidium, 410 Chlora, Phyllobium, - 551 Coffea, CJercospora, - 515 Fabraea, 2r,-, Cldoranthy, 33, 90 Hemileia, 361 Isariop.sis, 520 Chloris, Ustilago, - 299 Pellicularia, - 181 Melampsorella, 370 Clilorcjsis, - - 32 Ramularia, 502 Peronospura, - 134 Chrysanthemum, Coix, Ustilago, - 294 Sorosporium, - 325 Aecidium, 351, 409 Colchicum, Urocystis, 316 Ustilago, 297 Oidium, - - 499 Uromyces, 338 Cerato'pliyllum, Septoria, - 478 Colutea, Uromyces, - 337 C'lilorDchytrium, - 550 Chrysosplenium, Comarum, Doassansia, 324 Cereals (under Avena, Hor- Entyloma, - 312 Compositae, Aecidium 409 deuin, Secale,Triticinn) Puccinia, - 361 Bremia, - 132 Cereal-rust, - S 2, 84 Cichorium, Cystopus, 127 Chaerophyllum, Puccinia, 353, 355 Erysiphe, 175 Aetinonema, - 474 Sclerotinia, - - 264 Peronospora, - 134 Caeoma, 419 Cicuta, Puccinia, - 355 Plasmopara, - 131 Protomyces, - 138 Cineraria, Aecidium, 352 Protomyces, - 141 Puccinia, - 340 359 Bremia, - 132 Puccinia, 353 Chamaecyparis, Circaea, Aecidium , - 409 Sphaerotheca, 173 Gyninosporangium, Melampsora, - - 370 Synch ytrium, 109 401 , 402 Puccinia, - 361 Conifers, Agaricus, - 457 Pestalozzia, - 494 Cirsium, Aecidiun , 351 Botrytis, 268 Chamerops, Cystopus, 127 Diplodia, 472 Anthostomella, 226 Pliyllosticta, - 464 Fusoma, 504 fUaphiola, - 325 326 Puccinia, 35 3, 361 Pestalozzia, - 494 Chamomilla, Cystopus, 127 Synchytrium,- 109 Phytophtliora, 117 Ciianipignon blanc, - 202 Citron (see Citrus me iica) Polyporus, - 450 452 Chara, Entophysa, - 548 Citrus, Capnodium, 182 Rhizina, - 273 Cheirantlius, Cladosporium, 509 Conium, Puccinia, 353 Cercospora, - 515 Colletotriclium, 487 Conopodium, Aecidium ,409 Cystopus, 126 Dendrophoma, 469 Puccinia, 355 Peronospora, - 133 Fusarium, 521 Conservation of Host, 21 Chelidonum, Caeoma, 419 Fusisporium, - 521 Convallaria, Chenopodiaceae, Meliola, - 181 Aecidium, - 340 410 Peronospora, - 132 Penicillium, - 180 Dendrophoma, 469 Plionia, - 469 Pestalozzia, - 494 Heterosporium, 516 Chenopodium, Pleospora, 221 Convolvulaceae, ('lailocliytrium. 114 Spliaerella, - 215 Cystopus, 127 Phyllosticta, - 465 Sporidesmium, 221 Convolvulus, Puccinia, 341 Uromyces, 337 Claytonia, Peronospoi a, 134 Thecaphora, - 324 Cherry (see Pruiius avium Clematis, Copper salts as Fungi- and Prunus Cerasus) Aecidium, 34 9,409 cides, 06, 69, 122,171 ,467 II. genj:ral index. 585 PAGE PAOE PACE CoraJliorTiiza,,Mycorhiza, 97 Erysiphe, - 175 499 Phyllosticta, - 463 Cork (see Wound-cork) Hypnochus, - 428 Physalospora, 218 Cornus, Cryptomyces, 248 Macrosporium, 518 Uromyces, - 337 338 Erysiphe, 17.J Peronospora, - 134 Phyllosticta, - 464 Pythium, 117 D Septoria, 478 Scolecotrichuni, 508 Dactylis, Entyloma, - 312 Corydalis, Aecidiuni,- 410 Cucurbita, Bacteria, - 536 Epichloe, 191 Caeoma, 419 Colletotrichum, 4S6 Puccinia, - 345 346 Entyloina, 312 Peronospora, - 134 Sclerotium, - 266 Peronospora, - 134 Cucurbitaceae, Phonia, 469 Tilletia, - 310 Corylus, (Jnoinoniella, 224 Sclerotinia, - 265 Uromyces, 336 AJtiniiaiiia, 224 Spliaerotheca, 173 Dahlia, Sclerotinia, - 264 Phyllactinia, - 178 Cupressus, Agaricus, 457 Dammara,Peridermium,417 Polyporus, - 439 444 tiymnosporangium. 403 Damping-otf, 116 Septogloeum, - 496 Pestalozzia, - 494 Dandelion (see Taraxacum) Cotoneaster, Cupuliferae, Daphne, Sphaerella, - 215 Sclerotinia, - 201 Mycorhiza, - 93, 94 Datura, Cercospora, - 515 Cotton (see Gossypium Cycads, Anabaena, - 544 Daucus, Heterosphaeria ,249 ,, freiiching, 522 Cladosporium, 509 Phoma, - 468 Cotton-woods (see Populus) Cyclamen, Plasmopara, - 128 Coucli grass (see Triticum) Colletotrichum, 488 Polydesmus, - 221 cowberry 1 (^.^Vaccinium) Cranberry J Septoria, Thiclavia, 478 183 Protomyces, - Rhizoctonia, - 138 202 Crataegus, Asteroma, 470 Cydonia, Bacteria, - 531 Sclerotinia, 264 Fusidadiuin, - 507 Cercospora, - 515 Sporidesmiuni, 221 (iyniiiosporangiuni. Entomosporium, 480 Desmodium, 385, 391, 397, 401-403 Gymnosporangium, 385, Microsphaera, 176 Pestalozzia, - 494 391,401 403 Ramularia, - 502 Phleospora, - 478 Hendersonia, - 475 Dentaria, Puccinia, - 359 Podosphaera, - 174 Ovularia, 500 Dianthus, Ascochyta, 473 Polyporus, 450 Phoma, - 468 Bacteriosis, - 532 Koestelia, 3S5, 397 402 Roestelia, 391 Botrytis, 500 Septoria, 476 Spliaeropsis, - 472 Fusarium, 522 Tapluina, 150, lo3 106 Taphrina, 150, 154 168 Heterosporium, 516 Crepis, I'uccinia, 353 Cynanclium, Macrosporium, 518 .Syncliytriuin, 109 Croiiartiuni, - 381 Puccinia, 361 Cress (see Lepidiuni) Cynara, rvamularia, - 502 Septoria, 477 ,, ■water(seeNasturtiuin) Cynodon, Pliyllachora, •229 Sorosporium, - 325 Croton, Aecidium, 410 Tilletia, - 310 Urocystis, 319 Crowberry (see Empetrum) Ustilago, 294 Uromyces, 334, 336 337 Cruciferae, Cystopus, 124 Cynoglossum, Ustilago, 297 Erysiphe, 175 Peronospora, - 134 Volutella, 520 Peronospora, - 133 Cyperus, Schiuzia, - 326 Dicentra, Aecidium, - 410 Plasmodiopliora, 524 Cytisus, Ceratophorum ,511 Peronospora, - 134 Pythiuni, 116 Cucurbitaria, - 206 Digitalis, Ascochyta, 473 Cucumber (see Cucuniis) Darluca, 474 Ramularia, - 502 Cucumis, Bacteria, - 536 Diplodia, 209 Digitaria (see Panicum ) Cladosporium, 510 Microspliaera, 176 Dill (see Anethum) CoUetotriclium, 486 Peronospora, - 133 Diplachne, Ustilago, - 293 586 II. GENERAL INDEX. Dipsacus, Peronospora, Disposition : Chap. V. Doniatia, - 9:i, 99, Doronicum, T'uccinia, Don). ling of Flowers, Douglas Fir (see Pseiulo tsuga) Draba, AecitHuni, Puccinia, Dracaena, Ustilago, - Dry-rot = Morulius. Dryas, Didymosphaeria, Synchytriiun, Durra (see Sorghum) Septoria, PAGE - 478 Sphaerotheca, - 174 Uretlo, - - 420 Ventm-ia, - 218 Kpipliytes, - 8, 10 Ean celeste, . . Q[ Echeveria, Endophyllum, - 40-J Echinocystis, Peronospora, - - 1,34 Echinospermum. Peronospora, - 134 Ectotrophicmycorhiza, 94 Egg-plant (see Solannm Melougena) Elder (see Sambucus) Eleagnaceae, Mycorhiza, 99 Elm (see Ulnms) Elodea,C'hlorochytrium, 550 Elymus, Puccinia, 345, 348, 354 Ustilago, - . 293 Empetraceae, Mycorhiza, 98 Empetrum, Caeoina, - 380 Chrysoniyxa, - - 380 Melasmia, - . 479 Podosphaera, - - 175 Rhytisnia, - . 24(j Sclerotinia, - . 260 Endophytes, - - 8 11 Endotrophie, Mycorhiza, 93 Enzymes, - . 35^ 37 Epacrideae, Mycorhiza, 98 phedra, Peridermium, 417 Epilobium, Melampsora, - - 370 Plasmopara, - - 131 Puccinia, - - 341 Ramularia, - . 502 Epipogon, Mycorhiza, 97 Equisetum, Pythium, 116 ErantMs, Aecidium, 409 Urocystis, - . 316 Ergot (see Claviceps) Ergotism, symptoms, 193 Erica, Hypoderma, - 234 Leptosphaeria, - 221 Venturia, - - 218 Ericaceae, Exobasidium, 423, 427 Mycorhiza, - - 98 (see also Vaccininm) Erigeron, Aecidium, - 411 Basidiophora, - 127 Entyloma, - - 312 Eriksson on Cereal-rusts, 82, 332, 345 Eriophorum, Leptostroma, - - 480 Puccinia, - 352, 3.54 Eryngium, Entyloma, 312 Puccinia, - - 340 Erythraea, Phyllobinm, 551 Eucalyptus, Didymosphaeria, - 218 Pestalozzia, - - 494 Ustilago, - - 299 Euonymus.Caeoma, 368, 419 Corcospora, - - 515 Microsphaera, - 176 Venturia, - - 218 Euphorbia, Aecidium, - 24, 410 Endophyllum, - 403 Fusicladium, - - 508 Leptostroma, - - 480 Melampsora, - - 370 Peronospora, - - 135 Ravenelia, - - 403 Uromyces, 334, 336, 337 Euphrasia, Colcosporium, - 376 Tuburcinia, - - 321 Exoasceae, parasitic, 144 PAGE F Fagopyrum, Phytophthora, - II7 Eamularia, - - 502 Fagus, Actinonema. - 474 Agaricus, - . 461 Hydnuni, - . 432 Myxosporium, - 486 Nectria, - - 186 Pestalozzia, - . 493 Phyllactinia, - - 178 Phytophthora, - II7 Polyporus, 435, 444, 450 452 Qiuiternaria, - - 226 Slime-flux, - 143, 144 Fennel, Rhizoctonia, - 202 Ferments, - 2, 16, 35, 37 Ferns, Cryptomyces, 248 Sphaerella, - - 215 Taphrina, 29, 149, 153 Uredinopsis, - 141, 420 Urobasidinm, - 427 Festuca, Isaria, - - 519 Puccinia, 345-349, 354 Tilletia, 310 Urocystis, 316 Ustilago, 288 Ficus, Cercospora, 515 Uredo, - 420 Ustilago, 299 "Finger and Toe," - 524 Fir, silver (see Abies) Flax (see Linum) Flower-hypertrophy, 26 Flowering, premature 20 Flux of Trees, - 142 Fly -wood, - 430 Forests, close and mixed, 80 Fragaria, Ascochyta, 473 Peronospora, - 134 Ramularia, 214 Sphaerella, - 214 Synchytrium, 111 Thecaphora, - 325 Fraxinus, Actinonema, 474 Aecidium, 410 Ascochyta, - 473 Bacteria, 533 II. GENERAL INDEX. 587 PAGE Cercospora, - - 515 Cylindrosporium, - 489 Hysterographium, 233 Pestalozzia, - - 493 Phyllactinia, - - 178 Polyporus, 439, 444, 445, 452 Scolecotricluini, - 508 Septogloeum, - 496 Septoria, - - 478 Fiitillaria, Uromyces, 338 Fruit-rot, - 58, 115, 179 Fungi, pathogenic, - 104 ,, classification, - 105 ,, heteroecious, 45, 74, 331 „ in fodder, 85, 30G ,, sexuality, 104, 135 Fungicides, - - 68 Fungus-digesting plants, 92, 97 ,, -galls, 15, 25, .32, 33, 40, 300 ,, -roots, - - 93 „ -traps, - 92, 97 Gagea, Puccinia, 356 Synchytrium, 111 Uromyces, 338 Ustilago, 299 Galanthus, Botrytis, - 500 C'aconia, 368 Sclerotinia, 270 Galega, Uromyces, - 337 Galeopsis, Phyllosticta 465 Galium, Melampsora, 370 Melunotaenium, 314 Phacidium, - 241 Puccinia, 341,359 361 Synchytrium, 113 Gaultheria, Synciiytriuni, 109 Genista, Didymosphaeria, - 218 Ehizobiuni, - 101 Uromyces, .337 Gentiana, Botrytis, - 268 Cronartium, - 381 Heterosphaeria, - 249 Mycorhiza, - - 97 Puccinia, - - 341 Sclerotinia, - - 268 Geraniaceae, Sphaerotheca, - 173 Geranium, Botrytis, - 269 Coleroa, - - 195 Plasmopara, - 130, 131 Puccinia, - - 359 Ramularia, - - 502 Stigmatea, - - 210 Synchytrium, - 109 Tuburcinia, - - 322 Uromyces, - - 334 Venturia, - - 218 Geum, Depazea, - 465 Peronospora, - - 134 Gilia, Aecidium, - 411 Puccinia, - - 355 Gladiolus, Urocystis, - 316 Glaux, Aecidium, - 336 Glechoma, Puccinia, - 361 Itaiiiularia, - - 502 Gleditschia, Cercospora, 515 Glyceria, Cladochytrium, - 114 Claviceps, - - 194 Ustilago, - 293, 294 Glycyrhiza, Uromyces, 337 Gnaphalium, Entyloma, 312 Golden-rust, - - 348 Goodyera, IMycorhiza, 97 Gooseberry (see Kibes) -mildew, - - 173 Gossypium, Cercospora, 515 Colletotriclmin, - 487 Fusarium, - - 522 Macrosporium, - 518 Ramularia, - - 502 Sphaerella, - - 214 Uredo, - - - 420 Gourd (see Cucurbita) Grain-smuts, - 65, 221 (see also Ustilagineae) Gramineae, Ascochyta, 473 Claviceps, - - 191 Dilophia, - - 222 Dilophospora, - 479 PACE p]pichloe, - - 191 Erysiphe, - - 175 Exobasidium, - 427 Fusarium, - - 520 Isaria, - - - 519 Mastigosporium, - 504 Oidium, - 175, 499 Ophiobolus, - - 222 Phyllachora, - - 229 Puccinia, - 341-349 Scolecotrichum, - 508 Septoria, - - 477 Ustilago, - 2SS, 306 Grape (see Vitis) Grape-fruit (see Citrus) Grasses (see Gramineae) Grass-mildew, - - 175 Gumming, 211,491,538 Gunnera, Nostoc, - 541 H Habitat-races, - - 3,32 Hail-wounds, - 61, 78 Hallimasch, - - 455 Hartig's, P., chief works, 37 Haustoria, - 8, 10, 12 Hawthorn (see Crataegus) Hazel (see Corylus) Heart-wood, antiseptic, 5, 76 Hedera, Ascochyta, - 473 Bacteria, - - 533 Cladosporium, - 510 Septoria, - - 478 Sphaerella, - - 215 Vermicularia, - 471 Hedysarum, Uromyces, 338 Heleocharis, Claviceps, 195 Helianthus, Plasmopara, 131 Puccinia, - - 340 Ramularia, - - 502 Sclerotinia, - - 264 Heliclirysuni, Entyloma, 312 Helleborus, Ramularia, 502 Urocystis, - - 316 Helosciadium (see Apium) Entyloma, - - 312 Hemi-parasite, - 3, 4, 6 Hemi-saprophyte, - 3, 4 Hemp (see Cannabis) 588 II. GENERAL INDEX. PAGE I PAGE I'ACIE Heinp-canker, - 265 Clithris, 248 Hepaticae, Nostoc, - 547 Iberis, Plasmodiophora 524 Dothidea, 230 Scliizophyceae, 546 Ilex, Diplodia, - 472 Gymnosporangium, 384, Heracleum, Impatiens, Depazea, 465 389, .391, 395, 401 -403 Hutcro-sphaeria, 249 Plasmopara, - 131 Hendersonia, - 475 Protinnyces, - 18S Puccinia, 356 Hei-potrichia, - 199 Puccinia, 840 Imperata, Ustilago, - 299 Lophodermium, 240 Taplirina, - l.")l 154 Indian Corn (see Zea) Pestalozzia, - 494 Heteroecisin, - 4,) :m Individuation, - 87 Pleospora, 511 Hieracium, Kntyloina, 312 Infection methods, 53, 56 Polyporus, 450 Puccinia, 353 Insect diseases, - 8 115 Stigmatea, 211 Hippuris, Uroinyces, 336 Inula, Coleosporium, 376 K Holcus, Puccinia, Tillctia, Hollyhock (see Althaea Holosapropliytes, 346 310 ) 3 Ipomoea, Coleosporium Puccinia, Vermicularia, Iris, Aecidium, - ,377 356 471 411 Kalmia, Synchytrium, Knautia, Ascochyta, Peronospora, - 28 Ustilago, 109 473 132 294 Holosteum, Ustilago, 297 Cladochytrium, 114 Koeleria, Puccinia, 354 Homogyne, Puccinia, 359 Helminthosporium, 512 Kohlhernie, or Krouf. 524 Honey-dew, - I SI 193 Puccinia, 3oo Honey-fungus, - 455 Schinzia, 326 L Honeysuckle (see Loni- Uredo, - 420 Labiatae, Erysiphe , - 175 cera) Isopyrum, Puccinia, . 341 Hop (see Hunuilus) Synchytrium, 112 Laburnum (see Cytisus ) Hop-mildew, 173 Ivy (see Hedera) Lactuca, Botrytis, 500 Hordeum, Erysiphe, 175 Ivy-canker, 533 Bremia, - 132 Helniintliosporium, Puccinia, 340 221 512 J Septoria, 477 Horniodendron, 505 Jasione, Puccinia, 359 Lamium, Ovularia, 501 Pliouia, - 467 Jausch, 484 Lampsana, Puccinia, - 340 Puccinia, - 345 348 Jensen's method, 66 Ramularia, - 502 Tilletia, 310 Juglans, Botrytis, 180 Larch (see Larix) Ustilago, 288 Cladosporium, 510 -canker, - 271 Hornbeam (sue Carpinus) Entorrhiza, - 326 Larix, Agaricus, 457 Horse-radish (see Armor- Marsonia, 491 Caeoma, - 366, 367 419 acia) Microstroma, - 497 Dasycypha, - 271 Hottonia, Doassunsia, 324 Penicillium, - 180 Heterosporium, 516 Hot-water sterilization , 66 Septoria, 478 Hypodermella, 234 Humulus, Capnodiuni, 181 Juncus, Puccinia, 354 Leptostroma, - 212 Oidium, 499 Rhytisma, 246 Lophodermium, 240 Sphaeiotheca, 173 Schinzia, 326 Nectria, 188 Hyacinth (see ^cilla) Tolyposporiuni, 305 Peziza, - 20 271 Hydrangea, Scptoria, 478 Urocystis, 319 Polyporus, 439 4.52 Hypericum, Uromyces, 336 Sphaerella, - 211 Melanipsora, - 370 Ustilago, 294 Tramctes, 453 Hypnum, Jungermanniaceae, Lathyrus, Diachora, - 230 Scotinosphaeria, 550 Ticiitei)ohlia, 551 Dicoccum, 506 Hypochoeris, Juniperus, Agaricus, 357 Peronospora, - 1.32 Hamularia, 502 Botrytis, 270 Thecaphora, - 324 Hypopitys, Mycorhiza, 93 Clasterosporium, - 511 Uromyces, 333 , 334 II. GENERAL INDEX. 589 PAOE PAGE PAGE Laurus, Peronospora, - 134 M Exobiisidium, 31 , 427 Liriodendron, Magnolia, Pestalozzia, 494 Leaf- cast, - 236 Gercospora, - 515 Mahonia, Aecidium, - 341 Ledum, Chrysoniyxa, 379 Gylindrosporium, - 489 Maize (see Zea) E.xoljasidium, Sclerotinia, 427 263 Leptosphaeria, Lithospermum, Synchytrium, Lollum, Fusarium, 221 111 Majanthemum, Aecidium, 349 Leguminosae, 520 MalacMum, Ustilago, 297 Eiysiphe, 175 Ovularia, 500 Maladie digitoire. 524 Mycodomatia, 101 524 Puccinia, - 345 346 jNIal-di-gomma, - 521 Mycorhiza, 99 Thecaphora, - 325 Mallow (see Malva) Ravenelia, 403 Tilletia, - 310 Mai nero, - - 202 534 Lemna, Ustilago, 288 Malva, Ascochyta, - 473 Chlorochytrium, 549 550 Lonicera, Aecidium, 349, 409 Gercospora, - 515 Chlorosphaera, 548 Anthostoma, - 226 Phoma, - 469 Cornuella, 322 Ascochyta, 473 Puccinia, - 359 360 Eiidocloiiium, 551 Didyuiosphaeria, - 218 Mandarin (see Citrus) Olpidium, 107 Lasiobotrys, - 182 Mangel Wurzel (see Be a) Pythium, 117 Leptothyrium, 479 Mangold (see P.eta) Scotinosphaera, 550 Microsphaera, 170 Manure and Fungi, 07 279 Lemon {ace Citnxs) Nectria, - 185 ,, Plasmodiophora, 528 Lepidium, Aecidiuni, 410 Phyllosticta, - 464 Maple (see Acer) Cystopus, 126 Venturia, 218 Maranta, P^pichloe, - 191 Peronospora, - 133 Lophanthus, Matthiola, Lettuce (see Lactuca) Peronospora, - 134 Plasmodiophora, - 524 Libocedrus, Lotus, Ovularia, 501 Medicago, Gymiiosporangium, 401 Uromyces, 330 Peronospora, - 133 Lichen-symbiosis, 86 Lucerne (see Medicago; Pseudopeziza, 255 Lignification of cell-walls, 37 Lupinus, Gercospora, 515 Rhizoctonia, - 201 Lignin-destroying fung 1, 38 Cryptosporium, 489 Sclerotinia, - 265 Ligustrum, Aecidium, 409 Erysiphe, 175 Tilletia, - 310 Caeoma, 419 Pythium, 117 Uromyces, 336 Gercospora, - 515 Thielavia, 182 Medlar (see Mespilus and Gloeosporium, 485 Uromyces, 337 Amelancliier) Lilac (see Syriiiga) Luzula, Phyllachora, - 229 Melampyrum, Aecidium ,349 Lilium, Aecidium, 349 410 Puccinia, - 352 354 Coleosporium, 376 Botrytis, 268 Urocystis, 316 MeUca, Puccinia, 346 Peronospora, - 135 Ustilago, 294 Melon (see Gucumis) Sclerotinia, - 268 Lychnis, Ovularia, 500 ,, water (see Gucumis) Uromyces, 338 Puccinia, 340 Mentha, Gladochytrium 114 Lima bean (see Phaseolus) Septoria, 478 Endosphaera, 551 Lime ov Linden (see Til la) Sorosporium, - 325 Puccinia, 341 Limnanthemum, Uromyces, 337 Menyanthes, Aecidium, - 352 410 Ustilago, - 27 297 Gladochytrium, 114 Stomatochytrium, - 550 Lycium, Microsphaera, 176 Mercurialis, Limosella, Doassausia, 324 Lycopodium, Pythium, 116 Caeoma, - - 367 419 Linaria, Entyloma, - 312 Lycopus, Aecidium, - 411 Gercospora, - 515 Melanotaenium, 314 Lysimachia, Aecidium, 351 Synchytrium, 113 Peronospora, - 134 Phyllobium, - 551 Mespilus, Linum, Melanipsora, - 369 Synchytrium, 111 Fusicladium, - 508 590 II. GENERAL INDEX. PAdK PAGE PAGE Mespilus, Uromyces, 338 Oat (see Avena) Gyiunosporangium, Ustilago, 299 Oenotliera, Aecidium, 411 391 397 Mycocecidia, 25 Peronospora, - 134 Mucor, - 180 Mycodomatia, - 93, 99 Puceinia, 355 Oidium, - 499 Mycorliiza, - 3 2,93 Synchytrium,- 109 Ovularia, - -261 m) Myosotis, Aecidiuin, - 411 Olea, Cercospora, 515 Peuicillium, - 180 Entyloma, 312 Cycloconium, - 506 Podosphaera, - 174 Peronospora, - 134 Polyporus, 447 Meuni, Tiiphragmium, 3(5-2 Synchytrium, 111 113 Twig-galls, - 532 Mignonette (see Reseda) Myosurus, Peronospora ,134 Oleaceae, Mildew, powdery (see Ery- Myrica, Pvamularia, - 502 Hysterographium, - 232 sipheae) Frankia, 101 Oleander (see Nerium) ,, false (see Pel ono- Myricaceae, Olive (see Olea) sporeae) Mycodomatia, 99 Rogna or Loupe, - 532 Milium, Pueciiiia, 34.-. Myricaria, Onion (see Allium) Tilletia, - 310 Didymosphaeria, - 218 Onion-rust, - 341 355 Millardet's vines, 82 Myrrliis, Puceinia, - 340 Onobrychis, Diachora, 230 Millet (see Panieum and Thielavia, 183 Sorghum) N Uromyces, 337 Mint (see Mentha) Narcissus, Puceinia, - 359 Orange (see Citrus) Mistletoe, - - IS, 64 Nardus, Claviceps, 194 foot-rot, - 521 Molinia, Claviceps, - 194 Narthecium, Entyloma 313 mal-di-gomma, 521 Fusarium, 520 Nasturtium, Cystopus, 126 sooty mould, - 182 Neovossia, 311 Nebbia nera. 484 OrcMdeae, Aecidium, 349 Puceinia, 349 Needle-cast, 211, 236 481 Caeoma,- - 368 419 Monotropa, Neottia, Mycorhiza, - 97 Gloeosporium, 485 Mycorhiza, - 8 7, 93 Nepeta (see Glechoma) Mycorhiza, - 97, 99 Urocystis, 319 Nephrodium (see Ferns ) Ornithogalum, Monoxeny, 45 Nerium, Capnodium, - .181 Heterosporium, 516 Morbe bianco, - 202 Cercospora, - 515 Puceinia, 356 Morus, Bacteria, 534 Nicotiana, Ascochyta, 473 Urocystis, 316 Cercospora, 515 Bacteria, 535 Uromyces, 338 Cladochytrium, 114 Erysiphe, 175 Ustilago, 299 Diplodia, 472 Oidium, - 499 Orobanche, Urocystis, 319 Gibberella, - 184 Peronospora, - 134 Oryza, Piricularia, 503 Helicobasidium, 429 Phyllosticta, - 464 Sclerotium, - 266 Nectria, - 185 Nucleus-parasites. 32 Tilletia, - 310 Piileospora, - 478 Nuile, - - - 508 Ustilaginoidea, 311 Polyporus, 445 Nuphar, Aecidium, 352 410 Ostrya, Taphrina, 150, 154 Septogloeum, - 49() Nutricism, - 88, 92 Oxalis, Sphaerella, - 215 Sphaerella, - 215 478 Nyctaginaceae, Oxyria, Puceinia, 355 Mountain Ash (see Pyrus Peronospora, - 135 Ustilago, 298 [.Sorl)iis] Aucuparia) Nymphaea, Mucilage flux, - 142 Aecidium, - 352, 410 P Mulberry (see Morus) Entyloma, 313 Paeonia, Cronartium, 382 Mulg-edium, Puceinia, 340 Palms, Colletotrichum, 488 Muniniitication of fruits, 29 (jraiihiola. 325 Musa, Physalosijora, - 218 Oak (see Quercus) Pcstalozzia, - 494 Muscari, Urocystis, - 316 Oak-root fungus. 200 Thelephora, - 429 II, GENERAL INDEX. 591 PAGE Pandanus, Cephaleuros, 553 Nectria,- - - 188 Panicum, Pythium, - 116 Tolyposporium, - 306 Ustilago, 289, 291, 293 Papaver, Entyloma, - 312 1\ roiiospora, - - 133 Papilionaceae,Erysiphe, 175 Peronospora, - - 132 Parasites, - - 1-3, 7, 14 classification, - - 3 mode of life, - - 7 Paris, Aecidium, 349, 410 Mycorhiza, - - 32 Tuljurcinia, - - 321 Urocystis, - - 316 Parnassia, Aecidium, 352 Uromyces, - - 334 Parsley (see Petroselinum) Parsnip (see Pastinaca) Partridge-wood, - 431 Paspalus, Ustilago, - 294 Pastinaca, Cercospora, 514 CVrcosporella, - 503 Heterosphaeria, - 249 Pea (see Pisum) Pea-rust, - - - 334 Peach (see Persica) -curl, - - - 165 frosty mildew, - 503 -rot, - - - 497 Pear (see Pyrus communis) -blight, - - - 531 Pedicularis, Aecidium, - 351, 410 Penicillaria, 'iVjlyposporiuni, - 306 Pennisetum, Neovossia, 311 Pentstemon, Aecidium, 411 Peplis, Kiulosi)haera, 551 Peridermium, Tuberculina, - - 327 Persica (see also Prunus) Cercospora, - - 513 Cercosporella, - 503 Cladosporium, - 510 Clasterosporiuni, - 511 Gloeosporium, - 482 Monilia, - - 497 Phyllosticta, - 463 Picea, Aecidium, 377, Puccinia, 355 379, 407, 416 Sphaerotheca, 172 Agaricus, - 457 Taphrina, 150, 153 , 165 Barclayella, - - 373 Petasites, Aecidium, - 348 Chrysomyxa, - 379, 380 Coleosporium, - 377 Herpotrichia, - - 199 Coleroa, - 195 Lophodermium 237, 240 Petroselinum, Mycorhiza, - 95 Heterosphaeria, 249 Naevia, - - 238 Plasmopara, - 128 Nectria, - - 188 Puccinia, 353 Peridermium, 416, 417 Septoria, - 477 Pestalozzia, - - 493 Petunia, Polyporus, 440-450 Phytophtliora, - 122 Septoria, - 475 Sclerotinia, - 264 Trametes, - 453 Peucedanum, Trichosphaeria, - 197 Puccinia, 353 ,359 Picris, p]utyloma. - 312 Taphrina, 151 , 154 Puccinia, - 355 Phalaris, Pilea, Phytaphysa , - 554 Cladocliytrium, - 114 Pimpinella, Puccinia, 346 , 349 Puccinia, 340, 356 Sclerotium, - 266 Thecaphora, - - 325 Ustilago, 294 Pine (see Pinus) Phaseolus, Ascoch^ •ta, 473 ,, Cembrau (see Pinus Bacteria, 539 Cembra) Cercospora, - - 515 ,, Mountain (see Pinus CoUetotrichum, - 486 montana) Isariopsis, 520 „ Scots (see Pinus Phyllosticta, - 464 sylvestris) Phytophthora, 122 , , Weymoutli (see Finns Sclerotinia, 264 Strobus) Uromyces, 334 Pine-twister, - 364 Phegopteris (see Ferns Pinguicula, Ustilago,- 297 Phillyrea, Aecidium, - 410 Pinus, Agaricus, - 457 Uredo, - 420 Brunchorstia,- - 481 PMeum, J^pichloe, 191 Caeoma,- - 364 Puccinia, 345 348 Cenangium, - 251, 481 Phlox, Aecidium, 411 Cladosporium, - 509 Puccinia, - 355 Cucurbitaria, - - 210 Phoenix (see Palms ) Elaphoniyces, - 183 Phragmites, Claviceps, 194 Gymnosporangium, 396 Helminthosporium, 516 Lophodermium, - 240 Napicladium,- 516 Melanipsora, - - 364 Puccinia, - 349 Mycorhiza, - - 96 Ustilago, 293 Peridermium, - 376, Phyllanthus, Kavenelia 403 382 ,411-416 Phyteuma, Phoma, - 466, 468 Coleosporium, 377 Polyporus, 449, 450 Uromyces, - 338 Rhizina,- - 273 592 ir. (JENERAI. INDEX. - 210 - 188 382, 415 - 199 - 234 - 364 - 411 - 457 - 364 - 234 - 234 - 272 - 235 - 364 374, 376, Pinus, Sistotrema, - 433 Trametes, - - 453 Twig-galls, - 532, 533 drying up of twigs, 481 Pinus Cembra, Cucurbitaria, - Nectria, - Peridennium,- Pinus montana, Herpotrichia, - Hypoderinella, Melam psora, - Pcri8S, 293 - 356 Tropaeolum, Pleospora, 221 Tsuga, Perideriniuni, 417 Trichosphaeria, - 197 Tulipa, Botiytis, - 500 Puccinia, - - 359 Sclerotium, - - 5U0 Ustilago, - - 299 Turnip (see Brassica) Turritis (see also Arabis) Urocystis, - - 319 Tussilago, Asteroma, 470 Colcosporium, - 376 Puccinia (Aecidium), 348 Raiiiularia, - - 502 Twig-galls, - - 532 Tyloses, ... 76 Typha, Heterosporium, 516 Ustilago, - - 293 U Ulmaceae, Taphrina, - Ulmus, Apiosporiuni, Asteroma, Ceratophorum, Cladosporiuni, Dothidella, - Nectria, - Pestalozzia, - Phleospora, - Phyllachora, - Piggotia, Pleospora, Polyporus, 435, 444, Septogloeum, - Slime-Hux, Taphrina, - 149, Uucinula, Umbelliferae, Erysiphe Heterosphaeria, Phoma, - Protomyces, - Puccinia, - 353, Umbilicus, Puccinia, - Uredineae, Darluca, - Tuberculina, - Uromyces, Darluca, - Urtica, Aecidium, Ramularia, 149 181 470 512 511 230 185 494 478 496 230 221 445, 4.52 496 143 154 178 , 175 249 469 138 359 361 474 327 474 349 502 Khytisma, - - 246 Septoria, - - 478 Thecaphora, - - 325 Urticaceae, Peronospora, 1 35 V Vaccinium, Calyptospora, - 370 Exobasidium,- 423, 426 Gibbera, - - 204 Melampsora, - - 370 Podosphaera, - - 1 75 Sclerotinia, 256-260, 263 Synchytriuni,- - 109 Valeriana, Puccinia, - 356 Uromyces, - - 334 Vanilla, Gloeosporium, 485 Veratrum, Heterosphaeria, - 249 Puccinia, - - 355 Uromyces, - - 337 Verbascum, Phoma, - 469 Ramularia, - - 502 Uromyces, - - 338 Veronica, Ovularia, - 501 Peronospora, - - 134 Puccinia, - - 361 Schroeteria, - - 328 Septoria, - - 478 Sorosphaera, - - 530 Stysanus, - - 519 Vetch-rust, - - 333 Viburnum, Actinonema, 474 I'ercospora, - - 515 Microsi:)haera, - 176 Plasmopara, - - 131 Ramularia, - - 502 Vicia, Ascochyta, - 473 Cercospora, - - 515 Erysiphe, - - 175 Peronospora, - - 132 Phyllosticta, - - 464 Uromyces, 333, 334, 336 Vinca, Puccinia, - 356 Vine (see Vitis) bird's eye rot, - 467 black rot, - 216, 484 false mildew, - 129 598 II. (JENERAL INDEX. Vine, mildew, - 17( root-fungus, - - 20'. vine-epidemics, SI, 84 white rot, - - 471 Vines, American hybrid, 81 Vingerziekte, - - 524 Viola, Aecidium, - 410 Cercospora, - - 515 Gloeosporium, - 485 Ovularia, - - 500 Peronospora, - - 134 Phyllosticta, - - 464 Pucciuia, - 840, 859 Synchytrium,- 112, 118 Urocystis, 16,21, 81,817 Violet-rust, - - 840 Viscaria (see Lychnis) Vitis, Ascochyta, - 478 Aureobasidium, - 428 Bacteria, - - 534 Botrytis, - 180, 267 Cercospora, - - 518 Cladochytrium, - 114 Cladosporium, - 510 Colletotrichum, - 488 Coniothyrium, - 471 Dematophora, - 202 Gloeosporium, 482, 484 Laestadia, - • 216 Leptosphaeria, - 221 Oidium, - - 177, 499 Penicillium, • - 180 PAfiK Phoma, - - 216, 467 Plasmodiophora, 528, 529 Plasmopara, - 81, 128 Pseudocommis, - 529 Sclerotinia, - - 267 Septosporium, - 519 Sphaccloma, - - 467 Sphaerella, - - 215 Uncinula, - - 176 Uredo, - - - 420 W Wallflower (see Cheiran thus) Walnut (see Juglans) Weinstockfaule, - 202 Weymouth Pine (see Pinus Strobus) Wheat (see Triticum) White-rot of timber (due to Polyporeae) Willow (see Salix) Witches' Broom, due to Aecidium, 18, 24, 72, 88, 404, 410 Caeoma, - - - 418 Exoasceae, 19, 24,52, 145, 158, etc. Piavenelia, - - 408 Wood-destroying fungi, 5, 34, 86, 62, 72 (see also Polyporeae, Agaricus, Nectria, etc.) Wound-cork, - 42, 76 ,, -duramen, - 76 ,, -infection, - 75 ,, -parasites, 5, 17, 72, 75, 142 (see also Polyporeae, Nectria, etc.) ,, -treatment, - 75 Wounds from animals, 78 X Xanthoxylum, Aecidium, - - 410 Yeast (see Sacchai omyces) Yew (see Taxus) Z Zea, Bacteria, - 535 Helininthosporium, 512 Pucciuia, 353 Pythium, 116 TiUetia, - 310 Uredo, - 420 Ustilago, 279, 281 282 ZlTiTiia, Sclerotinia 264 Zizania, Ustilago, 294 Zizyphus, Cephaleuros, 553 Zoocecidia, 25 jj. C. StoU Colfcl*