r 
 
THE LIBRARY 
 
 OF 
 THE UNIVERSITY 
 
 OF CALIFORNIA 
 
 PRESENTED BY 
 
 PROF. CHARLES A. KOFOID AND 
 MRS. PRUDENCE W. KOFOID 
 
MICROSCOPIC OBJECTS 
 
 FIGURED AND DESCRIBED. 
 
 BY 
 
 JOHN H. MARTIN, 
 
 HONORARY SECRETARY TO THE MAIDSTONE AND MID-KENT 
 NATURAL-HISTORY SOCIETY. 
 
 LONDON: 
 JOHN VAN VOORST, 1 PATERNOSTER ROW. 
 
 MDCCCLXX. 
 
PRINTED BY TAYLOR AND FRANCIS, 
 RED LION COURT, FLEET STREET. 
 
K- 
 
 A13 
 
 TO 
 
 MY VALUED FRIEND 
 
 DB, BOWERBANK, F.R.S., F.L.S., F.E.M.S., &c., 
 
 I DEDICATE THIS WORK. 
 
 J. H. MARTIN. 
 
 M375I7G 
 
PREFACE. 
 
 MICROSCOPY has of late years taken such a hold on cultivated 
 minds, that I believe an apology for sending this work into 
 the world is scarcely needed. 
 
 It commences with some of the primary forms of Vegetable 
 life, and proceeds onwards through the tissues to the woody 
 structures of the Exogens and Endogens, next descending to 
 the Acrogens, and so passing to the extreme limits of vege- 
 table life, as the Desmidiese &c., thence to the lower forms 
 of Animal life, the Infusoria, and on through the Radiata to 
 the Insects, which are drawn and described in their various 
 orders, and the minute organs figured separately. 
 
 In the concluding Plates are represented interesting and 
 characteristic geological structures, with some of the more 
 curious forms and groupings of crystals. 
 
 It has been my aim to represent as faithfully as possible 
 some of the forms of hidden nature ; and I sincerely trust 
 
VI PREFACE. 
 
 that they will be found useful both to the student and to the 
 lovers of natural beauty. My thanks are due to Drs. Griffith, 
 Smyth, Plomley, and other gentlemen for their kindness 
 during the progress of the work. 
 
 JOHN H. MARTIN. 
 
 Week Street, Maidstone, 
 December 1870. 
 
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MICROSCOPIC OBJECTS. 
 
 Fig. 1. The Yeast-plant (Torula cerevisise or T. sacchari), 
 x 240 diameters. 
 
 This drawing of the Yeast-plant may be taken to represent 
 the typical form of a single cell. The cells increase by the 
 process of budding. In some parts of the figure the cells 
 may be seen in the act of throwing out a bud ; while in others 
 they are united into a perfect chain, which corresponds to a 
 more advanced stage of growth. The manner in which this 
 plant causes the conversion of sugar into alcohol is at present 
 imperfectly understood ; but, from some cause, during the 
 growth of the plant, carbonic acid is thrown off, while alcohol 
 remains in the liquid. 
 
 This plant belongs to the Coniomycetous order of Fungi. 
 
 The cells vary from ^ m to -^^ inch in diameter. They 
 are best examined when mounted in liquid. 
 
 Fig. 2. Maple-blight (Uncinula bicornis), x 90. 
 
 This figure represents the well-known blight or mildew 
 which is found on the leaves of the Maple, chiefly in the 
 months of September, October, and the early part of Novem- 
 ber ; the hedges in the country may sometimes be seen quite 
 white with this blight. The fine fibres in the drawing illus- 
 trate the web of the mildew, and the globular bodies the 
 conceptacles, or cases, in which the eight sporangia are stored 
 for future use; each sporangium contains eight spores. 
 This blight belongs to the As corny cetous order of Fungi. 
 
 The diameter of the conceptacles is from ^ to -^ inch. 
 
 This object may be mounted either in the dry state, in 
 balsam, or in liquid. 
 
Fig. 3. 
 
 Fig. 4. 
 
 t.rH. 
 
 London. Join. "Van. Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 2 
 
 Fig. 3. Spores of the Mushroom (Agaricus campestris), 
 
 x200. 
 
 This drawing illustrates the spores, as they are called, of 
 the common Mushroom, drawn immediately after they were 
 shed by the mature plant. Spores agree so far with seeds, 
 that they reproduce the plant. In their natural growth on the 
 gills they are called basidiospores ; these are common to 
 both the Hymenomycetous and Gasteromycetous Fungi. In 
 the Hymenomycetous, of which the Mushroom is an example, 
 they are produced on the surface of the gills (hymenium) , and 
 generally at the four extremities of a branched cell. The 
 spores are at first nearly colourless, but afterwards gradually 
 acquire a brownish tint. In some species of Fungi they 
 remain white. 
 
 The spores are from -^^ to ^oVo inch in length, and from 
 -^1^- to 4 J^. in breadth. They are best viewed when mounted 
 in liquid. 
 
 Fig. 4. Frond of a Confervoid Alga (Chlorococcum 
 vulgare), x 200. 
 
 This drawing illustrates the green dust or powdery layer 
 (Chlorococcum vulgare) so commonly found on old palings, 
 trunks of trees, &c. The minute seed-like bodies, mostly 
 arranged in groups of fours, of which this substance consists, 
 keep on increasing by cell-division; at least, according to 
 our present knowledge, they have not been proved to arrive 
 at a higher state of being in this respect differing from the 
 spores or seed-like bodies of the Mushroom. It is thought 
 by some scientific observers that it is only a lower form of 
 some lichen ; but the present state of knowledge upon this 
 point is rather uncertain. 
 
 The diameter of the groups of spore-like bodies is from ^-^ 
 
 to wVo incn - 
 
 They may be mounted either in the dry state, in balsam, 
 
 or in liquid. 
 
Fig. 5. 
 
 Fig. 6 
 
 Icaioix JchiL Van Voorst MDCCCLXX 
 
 DicV.in.eor. Imp 
 
MICROSCOPIC OBJECTS. 3 
 
 Fig. 5. Cells from the Apple (Pyrus malus), x 100. 
 
 It will be noticed that some of these cells are darker than 
 the others ; these have been treated with sulphuric acid and 
 iodine, which causes the cell- contents or protoplasm to con- 
 tract towards the centre of the cell. Within each cell will 
 be found one or more nuclei, and within these the nucleoli ; 
 it is supposed by some that these are the life-centres of the 
 cell. 
 
 Sulphuric acid and iodine colour the cellulose of the cell- 
 walls blue, and at the same time render the nitrogenous pro- 
 toplasm yellowish brown. Cells are often found with thickened 
 walls (see fig. 18) , and also with pits or dots, from the irregular 
 formation of the cellulose (see figs. 8, 10, 14, &c.). 
 
 The cells are from -^ to T ^ inch in length, and from 
 to -^ inch in breadth. 
 
 They are best mounted in liquid. 
 
 Fig. 6. Transverse Section of the Pine-apple (the fruit of 
 Ananassa sativa) , x 240. 
 
 This section forms an example of the ordinary loose paren- 
 chymatous tissue so commonly met with in various fruits 
 and other cellular growths, such as exists also in most 
 annual plants. It will be found, however, that in the case of 
 fruits the cells are usually large, while in the stems, leaves, 
 &c. of plants the cells are generally small. 
 
 It is best preserved either in the dry state or in liquid. 
 
 B 2 
 
7. 
 
 Fig. %. 
 
 x H Martin aJ 
 
 LoncL-n, Jokn. Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 7. Transverse Section of the Stem of the Water 
 Plantain (Alisma plantago), x 30, Endogen. 
 
 This section of the stem of the Water Plantain has been 
 drawn especially to illustrate the extremely loose form in 
 which the air-passages are often found. They are divided 
 horizontally by membranous partitions, some of which are 
 seen in the figure. These are composed of minute cells, with 
 short processes and intervening air-spaces, somewhat resem- 
 bling the structure met with in the Rush. 
 
 This section is best mounted in liquid. 
 
 Fig. s. Transverse Section of Elder -pith (Sambucus nigra), 
 
 x90. 
 
 This section shows the pitted membrane which forms the 
 cells. The pitted appearance is caused by an irregular for- 
 mation of the secondary deposit. Although the pits may 
 seem to be holes in the membrane, on the application of 
 sulphuric acid and iodine they will be found to be coloured, 
 as well as the surrounding tissues, which would not occur if 
 they were holes. Membrane is sometimes thickened by a 
 dense deposit, so as to have nearly the appearance of bone 
 (see fig. 18 &c.). 
 
 This pith (Elder) is often used by microscopists to clean 
 their object- and eye-glasses. 
 
 It may be mounted dry or in liquid. 
 
Fig. 9. 
 
 Fig. 10. 
 
 JnaH. Maria, ainat. del. 
 
 oo., Imp. 
 
 london John. "Via "Vborat. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 9. Stellate Tissue from Rush (Juncus communis), 
 x 90, Endogen. 
 
 This drawing is from a transverse section of the pith from 
 the stem of the Hush, as seen under the parabolic reflector. 
 It illustrates the stellate parenchyma, or cellular tissue. The 
 form of the component cells is generally that of a six-rayed 
 star, the ends of the rays of one cell being in apposition with 
 those of the surrounding cells. The intervals between the 
 cells, or the intercellular spaces, as they are called, in this 
 case, as in most water-loving plants, contain air; and it is 
 this, together with the loosely formed stellate tissue, that 
 tends to make the Rush so light and elastic. When the 
 pith is mounted in liquid or in Canada balsam, the air is 
 displaced, and the whole appears transparent. 
 
 It is best seen when mounted dry, but may be well viewed 
 in liquid. 
 
 Fig. 10. Longitudinal Section of the Willow (Salix alba), 
 showing dotted ducts in situ, x 240, Exogen. 
 
 This section is the same as fig. 66, only much more mag- 
 nified; it illustrates the dotted ducts. Ducts are regarded 
 as a form of vascular tissue terminating in abrupt or blunt 
 ends, by which characteristic they may be distinguished from 
 liber -cells and vessels, which terminate in tapered ends (see 
 figs. 13, 14, & 17; also Wood Sections); when examined 
 under a high power, say ^, they appear much dotted, whence 
 the name. The tissue of which ducts are composed (unlike 
 true vascular tissue) cannot be unrolled. 
 
 It is best examined in the dry state. 
 
Fig. 11. 
 
 Fig. 
 
 adnat.<lel 
 
 louden. John. Vau. Voorst. MDCCCLXX. 
 
 Dickmeon. Irap. 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 11. Oblique Section of the Root of the Brake Fern 
 (Pteris aquilina), x 90, Acrogen. 
 
 This section shows the scalariform tissue in situ. As will 
 be perceived, it is seated in a mass of cellular tissue, of which 
 the section is chiefly composed. Around the scalariform 
 ducts there is an evident aggregation of smaller cells (see 
 fig. 12 for a further description). 
 
 It is best viewed in the dry state or in balsam. 
 
 Fig. 12. Scalariform Tissue from Brake Fern (Pteris 
 aquilina), x 220. 
 
 Scalariform tissue is found in close bundles ; and imme- 
 diately around these bundles are packed a quantity of wood- 
 cells (see fig. 11). These are again closely packed in paren- 
 chyma or cellular tissue. The name of the tissue is derived 
 from the Latin scala, a ladder, which the ducts greatly 
 resemble. It is chiefly found in the Ferns ; but when met 
 with in the higher plants, it has a tendency to pass into the 
 form of pitted ducts. Scalariform tissue may sometimes be 
 slightly unrolled. 
 
 It shows best when mounted in liquid. 
 
Fig. 13. 
 
 al oat. del 
 
 London, John. Va^t Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 13. Longitudinal Section of the Wood of the Elder 
 (Sambucus nigra), x 120, Exogen. 
 
 This figure illustrates the longitudinal sections of the 
 medullary rays, as seen in situ. They appear as dark, oblong, 
 and pointed groups of cells in the mass of the ligneous or 
 woody tissue. It is these cells which give the rayed appear- 
 ance to transverse sections of the Dicotyledonous woods (see 
 Transverse and Longitudinal Sections of the various woods, 
 figs. 68, 69, &c.). The rays cross the annual circles existing 
 in the wood, and which indicate the age of the Dicotyledonous 
 trees. These cells generally become closer as they advance 
 in age. 
 
 The object is best viewed in the dry state. 
 
 Fig. 14. Longitudinal Section of American Pine (Pinus 
 Strobus), x 120, N. O. Coniferse. 
 
 This section is used to illustrate the so-called glandular 
 tissue, which really consists, however, of pitted cells or 
 vessels. The cells are very numerous in this wood; and the 
 pits will be seen in each cell with a bordered outline, or, as it 
 is in reality, a slight concavity in the surrounding substance. 
 There are pitted ducts, as well as vessels, in other vegetable 
 structures (see fig. 8) . 
 
 The cross lines in this figure represent portions of medul- 
 lary rays. 
 
 The pits or dots on this tissue are often used to test the 
 quality of the object-glass of the microscope. When this is 
 good, they will appear free from colour. 
 
 They are best seen in the dry state. 
 
Fig. 15. 
 
 Fig. 16. 
 
 <\fl 
 
 Louden Jehu. Van. Voorst. MDCCCLXX 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 15. Transverse Section of the Stem of the Garden 
 Rhubarb (Rheum undulatum), x 30. 
 
 This transverse section of the Rhubarb is drawn to show 
 the natural position of the vascular tissue when seated in 
 a mass of cellular tissue. The dark spots illustrate the 
 fibro-vascular, and the lighter formation (which is composed 
 of cells) the cellular tissue. For a description of the vascular 
 tissue, see fig. 16. 
 
 This should be mounted in the dry state. 
 
 Fig. 16. Spiral-vascular Tissue from Garden Rhubarb 
 (Rheum undulatum), x 120. 
 
 Fibro-vascular tissue comprises fibro-vascular bundles, ves- 
 sels, ducts, &c. The drawing shows the spiral -vascular tissue 
 as seen in bundles when taken from the Rhubarb and other 
 plants. This tissue is most important in the growth of young 
 plants, as it then appears to conduct the juices of the plant. 
 Spiral-vascular tissue is characterized by a spiral formation of 
 the secondary deposit ; and forms elongated, acuminated cells 
 or vessels, which generally communicate with each other. The 
 spirals are generally single, but occasionally double &c. (see 
 fig. 17). In some vessels these are replaced by rings, when 
 they are called annular. Spiral tissue was formerly called 
 trachenchymatous, from the supposed resemblance to the air- 
 vessels of insects (see dissections of Insects). Scalariform 
 tissue is a kind of spiral- vascular tissue (see fig. 12). 
 
 This object should be mounted in liquid. 
 
Fig. 
 
 ai tut del 
 
 London JolmVln Voorst MDCCCEXT 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 17. Spiral-fibre Cells from a Cactus, x 120. 
 
 The bundles and vessels of spiral-vascular tissue, in some 
 cases, exhibit the fibre as consisting of two or more spirals, 
 although it is usually single, as in the drawing of the vessels 
 of the Rhubarb (fig. 16). But in the drawing we are now 
 considering, the pointed fibre-cells must be especially noticed. 
 One of them will be seen with the spiral fibre imperfectly 
 formed; from some cause the secondary deposit has not 
 developed a complete spiral, but formed a dotted cell instead. 
 An annular vessel will also be seen on the left-hand side at 
 the bottom of the drawing. 
 
 This object may be mounted dry or in liquid. 
 
 Fig. 18. Section of Vegetable-Ivory Nut (Phytelephas 
 macrocarpa), x 120. 
 
 This section of the Vegetable-Ivory nut is drawn to illus- 
 trate the thickening of the secondary deposit alluded to at 
 page 3 (fig. 5). When a section of this nut is made, and 
 ground down until it is very thin, and then mounted dry or 
 in balsam, it will exhibit bodies something of the shape of a 
 compressed cheese-mite (see Mites) . This peculiar appearance 
 is caused by the irregular thickening of the cellulose of the 
 cell-wall, called secondary deposit (see also fig. 48). 
 
 Cells that are to exist for a long time in any structure 
 always have their cell-wall thickened until it becomes of a 
 bony or horny nature. That this deposit has been gradually 
 formed, may be demonstrated by maceration, or the applica- 
 tion of sulphuric acid, which resolves the thickened cell- wall 
 into different layers. 
 
 This object is best mounted dry ; but it may be mounted 
 in fluid. 
 

Fig. 19, 
 
 Fig. 2,0. 
 
 Bio H Malta., ad aat del 
 
 loud on John. "Van "Tborst. MDCCCLXX. 
 
 Imp 
 
MICROSCOPIC OBJECTS. 10 
 
 Fig. 19. Liber-tissue from Jute (Corchorus capsularis), 
 
 x 200. 
 
 Liber-cells or -tissue constitute a form of prosenchymatous 
 tissue consisting of elongated cells tapering to a point at 
 each end. These are often united into bundles, as in Hemp, 
 Jute, &c. 
 
 When liber-fibres are treated with acids, their individual 
 appearance is considerably altered, although in their ordinary 
 condition they do not appear to differ ; but they may always 
 be distinguished from Cotton and other vegetable hairs by 
 their structure. 
 
 Most liber-cells appear to have rather a dense thickening 
 of the secondary deposit. 
 
 This tissue is best mounted in liquid ; but if required for 
 the polariscope, in Canada balsam. 
 
 Fig. 20. Laticiferous Tissue from the Celandine (Chelidonium 
 majus), x 120. 
 
 This tubular kind of structure pervades the tissues of the 
 Papaveracese, Euphorbiacese, &c., and may generally be distin- 
 guished from the surrounding structures by its peculiar 
 branched appearance, although in some cases it is nearly 
 simple and straight. The canals convey a kind of milky 
 juice, called latex, and they are generally regarded by scien- 
 tific authorities as being in some degree a part of the system 
 of vessels that contribute to the circulation of plants. The 
 canals seem to thicken in their coats by the deposition of the 
 latex. The common Celandine is one of the most handy 
 plants in which to observe this tissue. 
 
 It is best mounted in weak spirit and water. It may be 
 extracted by maceration in water, and subsequent dissection. 
 
Fig. 2,1. 
 
 Fig. 2,2,. 
 
 Jh.a K. Martia vi Hi," . 
 
 London John "Van Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 11 
 
 Fig. 21. Cuticle of an Orchis (Oncidium ?), x 120. 
 
 This cuticle seems to have rather dark stomata, placed in 
 the centre of some of the cells. What appear to be holes, 
 are really papillae on the surface of the cuticle. In this case 
 the cuticle would no doubt absorb the moisture from the 
 atmosphere much more quickly than in the ordinary form of 
 cuticle, with its larger number of stomata and guard-cells. 
 
 The cuticle seems to show best when mounted dry. 
 
 Fig. 22. Cuticle of Chrysanthemum (Chrysanthemum 
 Sinense), x 300. 
 
 Cuticles of plants, of which this may be taken as a type, form 
 a skin consisting of variously shaped cells with stomata, and 
 in some cases hairs scattered at intervals over the surface. 
 This cuticle was taken from the common garden Chrysanthe- 
 mum, and has hairs as well as stomata. Stomata have often 
 four guard-cells (see also fig. 24), but sometimes only two 
 (fig. 23) . Stomata occur chiefly on the undersides of leaves, 
 except in water-plants, in which they are found on the upper 
 surface of the floating leaves. They are sometimes found on 
 the collum of the apophyses of mosses, as in Funaria hygro- 
 metrica &c. The use of the stomata is to admit air to the 
 intercellular spaces of leaves &c. ; and no doubt they are 
 placed on the under surfaces to prevent their being choked 
 up with dust and other foreign matter. 
 
 This object may be mounted in liquid. 
 
 c 2 
 
Fig. 2,3. 
 
 Fig. 
 
 Tno.H Kwca ad uat dd. 
 
 London, John. Van. Voorst. MDCCCLXX. 
 
 L>i3lciixsoxL. I'm 
 
MICROSCOPIC OBJECTS. 12 
 
 Fig. 23. Siliceous Cuticle of Sugar-grass (Holcus 
 saccharatus) , x 120. 
 
 Siliceous cuticles are found chiefly in the Glumacese and 
 Equisetacese. The cells of this cuticle are rather large, and 
 the stomata small the latter having two guard-cells instead 
 of four, as in figs. 22 and 24. 
 
 The cuticle of this grass is easily prepared, the deposit of 
 silex being rather abundant. The best plan is to soak the 
 grass in water for about 24 hours, and then to boil in nitric 
 acid |, water |, for a short time, when the siliceous cuticle 
 will separate ; or it may be boiled in the pure acid. It may 
 then be mounted in liquid, or dried and mounted in balsam 
 for the polariscope ; but glycerine is best. 
 
 Fig. 24. Cuticle of Araucaria (Araucaria imbricata), x 120. 
 
 This cuticle of the Chilian Pine, on testing with the acids, 
 burning, &c., I find is not siliceous as is generally supposed, 
 but appears to consist of a tough cuticle highly imbued with 
 a resinous substance, so as to be inflammable at a burning 
 temperature. The stomata seem to have four " guard-cells," 
 two lower and two upper. In some leathery cuticles, the 
 cells surrounding the guard- cells appear to be elevated above 
 the surrounding surface. 
 
 This object may be prepared by boiling the leaf in nitric 
 acid, and mounting the cuticle so separated in any good 
 liquid. Or it may be dried and mounted in balsam as usual. 
 
Fig. 2,5. 
 
 Fig. 26. 
 
 . 
 
MICROSCOPIC OBJECTS. 13 
 
 Fig. 25. Siliceous Cuticle of Bearded Darnel-grass (Lolium 
 temulentum) , x 240. 
 
 This cuticle is taken from the Bearded Darnel, or Rye- 
 grass. When this grass grows in great quantities, as it does 
 occasionally, it is said to be very injurious to grazing cattle. 
 In the Grasses, Equisetacese, &c. the cuticle is almost always 
 strengthened by a deposit of pure silex, which may be easily 
 tested by burning a wheat-straw, when the original form 
 remains, which would not be the case if the cuticle had not 
 contained silex. Siliceous cuticles may be prepared by boil- 
 ing the stems for a long time in nitric acid ; but if the object 
 to be prepared is weak in silex, the acid must be diluted 
 with one-third part of water ; it may then be well washed in 
 water, and mounted in liquid, or dried and then mounted 
 in balsam in the ordinary manner. 
 
 Fig. 26. Ramenta, or Scales, from a Fern (Nothoclsena 
 Isevis), x60. 
 
 These scales are drawn as shown under polarized light. 
 On the creeping stems of various species of Ferns, or on the 
 leaf-stalks of scaly kinds, bodies may be found, which are 
 in this case called r amenta (Latin ramentum, a shaving). 
 In structure these membranous bodies appear to be closely 
 allied to the scales in fig. 27, the chief difference being 
 the point of attachment and the well-marked network of 
 the cells. The common Scale-Fern (Ceterach qfficinarum) 
 owes its remarkable appearance to these ramenta, or scales. 
 The stipes of the male Fern (Lastrea filix-mas) , and various 
 other British species of Fern, are covered with them. 
 
 They may be mounted dry or in liquid ; but if required for 
 the polariscope, in Canada balsam, or sometimes in glycerine. 
 
Fig. 
 
 Fig. 8. 
 
 Jiio.H.Ivf*rtin. ad nat.dd. 
 
 london JokTx Van. Voorst. MDCCCLXX. 
 
 Dickinson.. Tro/p. 
 
MICROSCOPIC OBJECTS. 14 
 
 Fig. 27. Scales from Elaeagnus (Elseagnus argenteus), x 50. 
 
 Scales of plants, which are chiefly found in those of the 
 natural orders Elseagnacese, Bromeliacese, &c., some of the 
 Rhododendra &c., are closely related in form to stellate hairs 
 (see fig. 29) . Like the hairs, they seem to be attached by 
 the centre to the leaf or stem on which they are growing. 
 By this peculiarity they may be distinguished from the 
 ramenta of Ferns, which are attached by the base (see fig. 26) . 
 Most of the scales of plants polarize highly, and they are 
 often of most beautiful stellate &c. forms. 
 
 These scales are best mounted in balsam for the polari- 
 scope, and in liquid for other examinations. 
 
 Fig. 28. Section of Leaf of Scented Geranium (Pelargonium 
 odoratissimum), showing the perfume-glands, hairs, &c., 
 x!20. 
 
 The strongly scented Geraniums are particularly adapted 
 for the observation of the glandular hairs ; and in this case 
 most particularly so. 
 
 These hairs are of a globular form at their extremities, the 
 globes containing a strong scent, varying in character in the 
 different species of plants from which they are taken. No 
 doubt it has often been perceived that Geranium-leaves &c. 
 yield a strong perfume when crushed ; this is caused by the 
 rupture of the globular scent- glands, or hairs. The other 
 hairs seen in the drawing are ordinary compound hairs, 
 composed of two or more cells. 
 
 This object is best seen when mounted in liquid. 
 
Fig. 9. 
 
 Fig. 30. 
 
 Jh.o.K.Marca.. .i tiat del 
 
 londca.. Jott Tan. Voorst MDCCCLXX. 
 
 Diclcinaoii 
 
MICROSCOPIC OBJECTS. 15 
 
 Fig. 29. Stellate Hairs from the Ivy (Hedera Helix), x 90. 
 
 These hairs are drawn as shown under the parabolic 
 reflector, and illustrate the stellate form of vegetable hairs. 
 The hairs are taken from the stem of the Ivy, on which they 
 may be seen in great abundance. They appear to consist of 
 groups of simple hairs joined at one end, so as to produce an 
 irregular stellate form. These hairs are compound, being 
 composed of three or more simple hairs, supported on a short 
 footstalk. There are many forms of compound hairs (see 
 figs. 28, 30, 31, &c.) . Some hairs, when young and uninjured, 
 are very favourable objects in which to observe the rotation 
 of the protoplasm or cell-contents. 
 
 Vegetable hairs are best seen when mounted in liquid. 
 
 Fig. 30. Hairs from Tobacco-plant (Nicotiana Tabacum), 
 
 x!20. 
 
 This object is drawn as seen under the parabolic reflector. 
 Tobacco is often largely adulterated with Dock, Cabbage, 
 Coltsfoot, &c., most of which plants have simple forms of 
 hair (see fig. 33), and may thus, under the microscope, be 
 distinguished from the true Tobacco-leaf or stalk, which has 
 compound hairs with a knob at the apex. Most of the hairs 
 are of a rather large size. 
 
 The best plan to mount this object is to boil a piece of the 
 stem of the plant in weak nitric acid, say acid 1 part, water 
 3 parts, when the cuticle will be seen to separate, and may 
 then be mounted in glycerine, or, what is better, alcohol and 
 water. 
 
Fig. 31. 
 
 Fig. 82. 
 
 JhaH-Meobu, ad nat del 
 
 london. John. Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 16 
 
 Fig. 31. Branched Hairs of the Great Mullein (Verbascum 
 Thapsus), x60. 
 
 It will be perceived from the drawing that this is another 
 example of compound hairs. In this case they take the form 
 of a hair branched at the joints in an irregular manner. 
 The large number of hairs on the Mullein is rather remark- 
 able, its leaves being quite woolly with them. This plant is 
 very common in some counties, more especially where the 
 soil is of a sandy or chalky character. 
 
 These hairs are best mounted in liquid. 
 
 Fig. 32. Cotton-fibre from Seed (Gossypium herbaceum), 
 
 x240. 
 
 These hairs, or fibres, have been drawn to illustrate the 
 difference between the various kinds of vegetable textile 
 fabrics, but more especially to show the difference between 
 cotton-fibre and the liber-fibre of jute (see fig. 19) the 
 cotton hairs appearing like a long flat band, or ribbon, while 
 the liber-cells, or fibres, of the jute are cylindrical and 
 pointed. To distinguish vegetable from animal fabrics, such 
 as wool, they may be boiled in a test-tube with liquor 
 potassae, when the animal hairs will be dissolved, and the 
 vegetable, such as cotton &c., will remain nearly intact. 
 
 This fibre may be mounted dry or in liquid, and in Canada 
 balsam when wanted for the polariscope. 
 
Fig. 33 
 
 Fig. 84 
 
 JJIO.H. Martin aul uatrlel 
 
 london. JofoxVan.'Vborst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 17 
 
 Fig. 33. Simple Form of Hair from the Cabbage (Brassica 
 oleracea), x 120. 
 
 The simple form of hair is very common on plants, although 
 perhaps not more so than the ordinary straight compound 
 hairs (see fig. 28) . The hairs consisting of only one cell 
 makes it an easy matter to distinguish, under a moderately 
 low power of the microscope, say a ^-inch, the compound 
 hairs with their knobbed cells of the true Tobacco, from the 
 adulterations with cabbage-leaves &c., most of which have 
 only simple forms of hairs. 
 
 These hairs, together with most vegetable hairs, are best 
 when mounted in liquid. 
 
 Fig. 34. Compound Beaded Hair from a Stamen of 
 Tradescantia, x 200. 
 
 This compound hair has been drawn to illustrate another 
 form that hairs sometimes take, viz. the beaded form. They 
 are to be found on the common Groundsel, Sow-thistle, and 
 other plants. In fact, on the Sow-thistle they are sometimes 
 so numerous as to give that plant a hoary or frosted appear- 
 ance. 
 
 For other forms of compound hairs, see figs. 28, 29, 30, 31, 
 &c. Hairs of plants are sometimes developed into the form 
 of stings (see fig. 35). 
 
 These beaded hairs may be mounted dry or in fluid. 
 
Fig. 35 
 
 Fig. 36 
 
 Jn.0. H.Martin, a-1 nat. del 
 
 London., Jolu)_V"aij. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 18 
 
 Fig. 35. Stings from Stinging -nettle (Urtica dioica), x 40. 
 
 Stings of plants may be regarded as 'enlarged forms of 
 hairs, having a bulbous base, in which the acrid or irritating 
 fluid is contained. They are chiefly found in the N. O. Urti- 
 cacese. The mode of action of the sting is as follows : 
 Directly the point of the sting is broken off, a fine tube is 
 left exposed ; and the sting being at the same time slightly 
 pressed upon its bulbous base, the acrid fluid rises through 
 this tube and enters the flesh at the point made by the punc- 
 ture of the sting. 
 
 These stings may be mounted dry or in liquid. 
 
 Fig. 36. Petal of Scarlet Pimpernel (Anagallis arvensis) , 
 
 x200. 
 
 This petal has been drawn to illustrate the spiral- vessels 
 which run up the veins of the petals of many flowers. Another 
 example is shown at fig. 38. Many of the Composite florets 
 show a similar structure well when mounted in fluid or bal- 
 sam ; the florets of Senecio Jacobaa form a case in point. 
 
 Transverse sections may be taken of some of the thicker 
 petals, as they often show the mamilla in its natural position 
 better than in a semiopaque view. 
 
 This petal is best mounted in balsam. 
 
Fig. 37 
 
 Fig. 88 
 
 Jno.H Martin, ai nat.del . 
 
 London. 
 
 MDCCCLXX. 
 
 Bic'kin.soxL, Irap. 
 
MICROSCOPIC OBJECTS. 19 
 
 Fig. 37. Petal of Geranium (Pelargonium), x 150. 
 
 The drawing of this petal is something like fig. 48 in 
 general appearance; but when the two are carefully com- 
 pared, they will be found to be quite different in structure. 
 For instance, the rayed appearance in the cells of the Gera- 
 nium is caused by a multitude of minute folds or wrinkles 
 radiating from a common centre in each cell. But it is 
 mainly the central mamillse that give the fine velvety feel to the 
 petals of many flowers, such as the Geraniums, Pansies, &c. ; 
 while the rayed appearance in the cells of the testa of the 
 Vegetable-Ivory nut is caused by the irregular formation of 
 the secondary deposit. 
 
 This petal is best mounted dry. 
 
 Fig. 38. Petal of a Crimson-flowered Cactus (Epiphyllum) , 
 N. O. Cactacese, x 350. 
 
 The colour- cells of this petal are rather large, and form a 
 wavy kind of structure. The colour of the petal is a deep 
 crimson. The petals seem to contain, amidst their surround- 
 ing tissue, a more than ordinarily large number of spiral- vas- 
 cular cells, which will be seen on referring to the drawing. 
 Many petals contain spiral- vascular cells, which generally run 
 through their entire length (see fig. 36). The best way to 
 mount this petal is simply to soak it in ether for a minute, 
 then to place it in sulphuric acid 1 part, water 2 parts, for a 
 minute or so, until the colour becomes strong, then to wash 
 and dry it, and to mount it in balsam as usual. 
 
Fin. 39 
 
 Fig. 40 
 
 n. Martin, ad. natdel 
 
 London Jolui. "Van "Voorst. MDCCCLXX. 
 
 Dickincon, Ii 
 
MICROSCOPIC OBJECTS. 20 
 
 Fig. 39. Petal of Fritillary (Fritillaria meleagris) , x 120. 
 
 The petal of this flower is rather remarkable for the irre- 
 gular formation of the cells of the cuticle, which will be 
 remarked on looking at the drawing. The flower is named 
 from the Jj&tmfritillus, a dice-box, the coloured markings on 
 the petals slightly resembling the board upon which dice are 
 thrown. 
 
 The petal, or rather the cuticle of the petal, of this flower 
 shows best when mounted dry. 
 
 Fig. 40. Pollen of Convolvulus (Convolvulus sepium), x 200. 
 
 The drawing illustrates the spherical form of pollen, men- 
 tioned at p. 21 (fig. 42). Many of the spherical pollens have 
 spiny processes proceeding from the outer cuticle as the pollen 
 of the Mallow, the Hollyhock, &c. A great many are also 
 furnished with ridges, as in the above drawing. Other ex- 
 amples may be found in the pollens of the Dandelion, Cobaa 
 scandens, &c. 
 
 Before mounting pollens in fluids, they should be placed in 
 a solution of gum or sugar, as this tends to mitigate the 
 endosmotic action. 
 
 In the case of this pollen, it is best when mounted in a 
 dry opaque cell. 
 
Fig. 
 
 Fig. 
 
 ad. oat. del. 
 
 London Jotn Van. Voorst . MD C C CLXX . 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 41. Pollen of Hyacinth (Hyacinthus orientalis), x350. 
 
 This drawing illustrates the elliptical form of pollen, men- 
 tioned below (fig. 42). The granular protoplasm, which, in 
 the case of pollens, is called the fovilla, appears to be of a less 
 dense character than in most of the elliptical pollens, and is 
 therefore not so much affected by endosmosis on the applica- 
 tion of fluids. The skin or cuticle also appears to be tolerably 
 thick. It will therefore be advisable to mount this pollen 
 in fluid. The colour of the pollen is yellow. 
 
 Fig. 42. Pollen of the Evening Primrose (CEnothera 
 biennis), x 120. 
 
 This form of pollen is rather uncommon, the general forms 
 being chiefly spherical, elliptical, &c. In some plants, as in 
 the Orchids, the pollen coheres in waxy masses. The remark- 
 able characters and forms of the ridges, furrows, &c. which 
 appear on most pollens, seem to be caused chiefly by the 
 contractions of the outer skin or cuticle ; these contractions 
 may often be noticed to have disappeared on the application 
 of liquids, such as water &c. Hence it is advisable to mount 
 pollens, when sufficiently transparent, dry, as the best way 
 to retain their natural forms. 
 
Fig. 43. 
 
 Fig. 
 
 J"no.H.]far*m. ad iiat del 
 
 London Jolm Van Voorst. MDCCC1XX. 
 
MICROSCOPIC OBJECTS. 22 
 
 Fig. 43. Pollen from Flower of Strawberry-tree (Arbutus 
 unedo) , x 200. 
 
 Many pollens have a remarkably fine and beautiful appear- 
 ance when viewed under the high powers of the microscope ; 
 by their structure, many Natural Orders of plants, and also 
 the different genera, may be distinguished from each other ; 
 but I doubt whether the species of one genus can always be 
 distinguished from those of another. Pollens have been 
 comparatively little studied, and in this field alone much 
 work may yet be done. 
 
 This pollen, being rather opaque, shows best when mounted 
 in the essential oil of lemon, or any other essential oil. 
 
 Fig. 44. Stamens and Pistil of Dead Nettle (Lamium 
 album), x20. 
 
 Stamens, as it is well known, deposit the pollen from their 
 anthers upon the stigma of the pistil of flowers, which is 
 depicted in this drawing. The pollen then throws out a tube, 
 which enters into the conduc ting-tissue of the pistil, and 
 passes on until it reaches an ovule or undeveloped seed, 
 which it then fertilizes. To investigate this fact, it is neces- 
 sary to cut a matured pistil from a partially withered flower, 
 subject it to moderate pressure, and mount it in fluid or 
 balsam. The stamens and the pistil of the Dead Nettle are 
 best when mounted in a dry opaque cell ; or they may be 
 mounted in balsam, and viewed under the parabolic reflector. 
 
Fig. 45. 
 
 Fig. 46. 
 
 -Pi 1,4-1 
 
 London Jblm. 'Van. Voorst. MDCCCLXX. 
 
 T)i ckinson. 1 
 
MICROSCOPIC OBJECTS. 23 
 
 Fig. 45. Seeds of the Least Toad-flax (Linaria minor), x 20. 
 
 The testa of this seed is much furrowed; and there are 
 many seeds partaking of this character, of which the Poppies, 
 Toad-flaxes, &c. contain some of the best examples. Many 
 seeds have also a number of rayed protuberances rising from 
 their surface, as in the Campions, Catchflies, &c. The testa 
 may be separated from the seed and mounted as a transpa- 
 rent object ; or the seeds may be mounted in a dry opaque 
 cell. But it is best, if possible, to mount them in both ways, 
 as the real structure is then better seen. Many seeds, when 
 viewed opaquely, have a striking resemblance to the eggs of 
 Moths and Butterflies (see Insects' eggs) . 
 
 Fig. 46. Seed of Eccremocarpus (Eccremocarpus scaber), 
 
 x20. 
 
 Winged seeds like the present always present a beautiful 
 structure under the low powers of the microscope. Some of 
 the best forms are Calosanthes Indica, Paulownia imperialis, 
 Lophospermum scandens, Pentstemon, &c. Seeds have two 
 skins or coats, called the testa and tegmen ; the former and 
 outer membrane (testa) is generally greatly thickened and 
 hardened by the formation of the secondary deposit, as in 
 fig. 48. Sometimes the surface is furrowed, as in fig. 45 ; 
 occasionally it is quite smooth ; and it is rarely covered with 
 spiral-fibrous cells, as in Collomia (fig. 47) . 
 
 Eccremocarpus-seeds are best prepared by boiling in nitric 
 acid 1 part, water 2 parts, which quickly changes the colour 
 to a light brown, when the centre of the seed must be taken 
 out, and the skin well washed and mounted in balsam as usual 
 if wanted for the polariscope, or, if not, in fluid. 
 
Fig. 47. 
 
 Fig. 
 
 ..-nil. ad itat del 
 
 Loadon John. Van Voorst. MDCCCLXX. 
 
 I^idcinoon, Irc-p. 
 
MICROSCOPIC OBJECTS. 24 
 
 Fig. 47. Testa of Seed of Collomia (Collomia grandiflora), 
 
 x50. 
 
 The spiral fibres in the cells of the testa of this seed form 
 a good object in which to observe the extreme elasticity of 
 spiral fibre. The best way to show it is to cut a very small 
 and thin slice from the outside of the seed, to place it on a 
 glass slip, and then add a drop of alcohol to it, and cover 
 with thin glass, next adding water in sufficient quantity to 
 fill up the space left between the glasses. If the object is 
 now viewed under an inch or J-inch object-glass, the uncoil- 
 ing of the spiral fibres will be beautifully seen. 
 
 It may be mounted in weak alcohol and water about 
 alcohol 1 part, to water 6 parts. 
 
 Fig. 48. Testa of Vegetable- Ivory Nut (Phytelephas macro- 
 carpa), x 120. 
 
 The structure of the testa of the Vegetable-Ivory nut is not 
 unlike that of the nut itself (see fig. 18), the peculiar rayed 
 appearance being also caused by the formation of the secondary 
 deposit. This kind of tissue is often called sclerogen. The 
 drawing might be mistaken for that of the petal of the 
 Geranium, which it greatly resembles ; but upon closer exa- 
 mination the cell-wall will be seen to possess a different 
 character (see fig. 37). The husk, or, as it is called, the testa, 
 of this nut is of a brownish colour ; it may be prepared by 
 grinding down to an extreme thinness, and then mounting in 
 Canada balsam in the usual manner. 
 
Fig. 49. 
 
 Fig. 50. 
 
 JhaH-Martui, ad. nat del 
 
 John Van Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 25 
 
 Fig. 49. Longitudinal Section of a Seed (Malope grandi- 
 flora), x30. 
 
 This drawing has been made to illustrate the chief parts in 
 the composition of a seed. The outer skin or testa is repre- 
 sented by the dark dotted outer part of the drawing ; the 
 inner skin or tegmen by the lighter part next to the testa ; 
 inside this, represented by the parallel lines with cross mark- 
 ings, is the seed proper, consisting of the young embryo 
 plant, or the life-centre of the seed. The structure and 
 shapes of seeds form a remarkably interesting subject for 
 investigation : for examples of seed-forms, see figs. 45 and 46. 
 The best plan to prepare sections of minute seeds is to imbed 
 them in softened gutta percha, let it harden, arid then to cut 
 sections with a fine scalpel. The sections may be mounted 
 in liquid or in Canada balsam. 
 
 Fig. 50. Section of Seed called "Grains of Paradise" 
 (Amomum Grana-Paradi'si) , x 200. 
 
 The structure of this seed, as shown by the drawing, con- 
 sists of layers of albumen interspersed with the oily or fatty 
 matter, of which the seed contains a large amount. On re- 
 ferring to the drawing, many globules of fat will be seen. 
 
 The albumen varies much as to quantity in the different 
 seeds taken from a pod of this plant. 
 
 The albumen (or, as it is sometimes called, the perisperm) 
 of seeds must not be confounded with the chemical substance 
 albumen, which is found nearly pure in the white of eggs &c. 
 
 Grains of Paradise are much used by publicans and others 
 in the adulteration of beer. 
 
Fig. 51. 
 
 Fig. 52,. 
 
 JhcxEMaztuL, ad nai del 
 
 Loncbn.. John. Van. Voorst . MDCCCIDOC. 
 
MICROSCOPIC OBJECTS. 26 
 
 Fig. 51. Starch from Wheat (Triticum vulgare), x 350. 
 
 Starch may be considered one of the most universal of 
 all the distinct vegetable substances, occurring, as it does, in 
 the form of minute transparent granules in all flowering 
 plants. This may be easily proved by taking a quantity of 
 any herbaceous leaves, stems, &c., bruising them in a mortar 
 until they are beaten into a pulp, then adding more water 
 and straining through flannel; and after the sediment has 
 settled at the bottom of the basin, the presence of the starch 
 may be detected by the application of iodine (see also fig. 53) . 
 
 This drawing represents the starch of Wheat, which may 
 be taken as an example of the lenticular or lens -like form of 
 starch. 
 
 This starch is best mounted in liquid. 
 
 Fig. 52. Starch from the Oat (Avena sativa), x 350. 
 
 The chief peculiarity of this starch is, that the small gra- 
 nules or grains are grouped together in round or oval masses. 
 These masses, when broken, have somewhat the appearance 
 of the Rice-starch represented in fig. 53. By this conglo- 
 merated appearance, the starch of the Oat may be distin- 
 guished from the other common starches found in the differ- 
 ent grains, such as those of wheat, maize, barley, &c. 
 
 The starch may be mounted in liquid. 
 
Fig. 53. 
 
 Fig. 54. 
 
 Jao-KMsutm ai:nal.del 
 
 loadoii John. Van "Voorst. MDCCCCXX. 
 
 Dickinson.. Imp. 
 
MICROSCOPIC OBJECTS. 27 
 
 Fig. 53. Starch from Rice (Oryza sativa), x 450. 
 
 The starch-granules of Rice, like those in the preceding 
 drawing of the Oat-starch, are massed together in a conglo- 
 merate form; but in this instance the granules are more 
 irregular in shape,, and also greatly pointed, which character- 
 istic gives the peculiar gritty feel to Rice-starch. 
 
 The presence of this, or any other kind of starch, may be 
 distinguished in any article adulterated with it, by the iodine 
 test, which is this : On placing a small quantity of mustard 
 (we will say for instance) under the microscope and adding 
 a small drop of the tincture of iodine to it, if starch in any 
 form is present a number of dark blue or black grains will 
 be seen ; these are the starch-granules, which have been so 
 coloured by the iodine. 
 
 Fig. 54. Starch from. Maize (Zea Mays), x 350. 
 
 These granules are taken from the centre of the Indian 
 corn, or Maize as it is generally called. The form is slightly 
 different from that of the granules which are found in the 
 outer part of the grain, which assume more of the hexagonal 
 form, together with a near resemblance to that of cellular 
 tissue, both of which appearances are caused by the pressure 
 of the entire mass upon each individual granule. 
 
 This and all the other starches show their structure best 
 when mounted in liquid. 
 
Fig. 55. 
 
 r. 56. 
 
 Jno.H. Martin., ad aat.dd. 
 
 loadon Jolm. Van. "Vbonrt MDCCCLXX. 
 
 DiclciiiBoii. Imp. 
 
MICROSCOPIC OBJECTS. 28 
 
 Fig. 55. Starch from the Potato (Solanum tuberosum), 
 
 x200. 
 
 This starch is drawn as viewed under the polariscope, and 
 exhibits the black cross which is seen in all large starches 
 when viewed under the polariscope. This makes it easy to 
 distinguish starch from all other substances when it is pre- 
 sent in any adulterated article. 
 
 Potato- starch forms one of the largest of the starch-gra- 
 nules, and is often used in the adulteration of arrowroot &c. 
 The granules, when mounted in fluid, exhibit the rings or 
 concentric layers of growth, as seen in fig. 51 ; but when 
 required for the polariscope, they show best when mounted in 
 balsam, or, what is better, in balsam dissolved in chloroform. 
 
 N.B. No heat must on any account be used in the mount- 
 ing of starches, as it destroys their structure. 
 
 Fig. 56. Starch from the Spanish Chestnut (Castanea 
 vulgaris) , x 350. 
 
 Most starches are found of various sizes, which arises from 
 their being in different stages of growth : the structural centre 
 is called the hilum ; and around this is deposited, in the course 
 of the growth of the granules, a series of concentric rings, 
 increasing in number according to its age (see fig. 51). A 
 great quantity of starch is found in nuts, and also in most 
 roots and seeds, it being the chief source of support to the 
 young plant. Starch is insoluble in cold water; but upon 
 the application of heat, sulphuric acid, &c., it loses its cha- 
 racteristic structure and becomes converted into a soluble 
 substance called dextrine. 
 
. 58. 
 
 adnatdd. DicTcmson, Imp 
 
 london John. "Vim. "Tborst. MDGCCIXX. 
 
MICROSCOPIC OBJECTS. 29 
 
 Fig. 57. Starch from Tapioca (Jatropha Manihot), x 350. 
 
 The granules of this starch are chiefly remarkable for their 
 form, and the cross mark at the hihim being rather larger 
 than in most other starches, the hilum generally forming a 
 small black dot. The shape of these granules is also peculiar, 
 being convex at one end and plane at the other. 
 
 Starches are best preserved dry when required for future 
 examination. 
 
 Fig. 58. Starch from the Carrot (Daucus Carota), x 350. 
 
 This starch has been drawn chiefly to illustrate the form of 
 the granules which are found in most of the flowering plants, 
 viz. the Exogens and Endogens. The form is generally glo- 
 bular, although other forms are occasionally found. The pre- 
 sence of these smaller starches is sometimes rather difficult 
 to determine, the iodine test being in this case superior to 
 the polariscope as a means of discovering them. They are 
 also very difficult to measure, many of them being of such 
 minute size that even the iodine fails to make them distinct 
 enough to measure with the micrometer. 
 
Fig. 59. 
 
 Fig. 60 
 
 Jr.o. K Majtui *A nai del 
 
 London. Jolm Van Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 30 
 
 Fig. 59. Transverse Section of Bauhinia (Bauhinia chinen- 
 sis), x20. N. O. Leguminosae, Exogen. 
 
 Exogenous are distinguished from endogenous plants by 
 having a bark, concentric annual growths of wood, and a 
 pith in the centre, also for having medullary rays or cells 
 proceeding from the pith to the bark. The bark, wood, pith, 
 &c. will be seen in this drawing ; and for a description of an 
 endogenous stem see fig. 72. Prosenchymatous cells, form- 
 ing woody tissue, are in greater abundance in the Exogens 
 than in the Endogens ; but the former contain less vascular 
 and cellular tissue than the Endogens. 
 
 Wood-sections are best seen when mounted dry, although 
 Canada balsam may often be used with advantage. 
 
 Fig. 60. Longitudinal Section of the Wood of the Cork-Oak 
 Tree (Quercus Suber), x 50. Exogen. 
 
 The ducts of this wood seem to be extremely large, and 
 the prosenchymatous or woody cells rather more closely con- 
 nected than in most woods. The wood of this species of Oak 
 has a thick bark, which is largely used in commerce under 
 the name of cork. This bark is composed of extremely 
 small and at the same time closely packed cells of cellular 
 tissue, which tends to give that fine elastic quality which 
 makes it so useful an article where these qualities are so 
 greatly needed. 
 
Fig. 61, 
 
 Fig. 62,. 
 
 Jno.H.Maibn.. ad -b&t del 
 
 Jolrn. Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 31 
 
 Fig. 61. Transverse Section of the Wood of the Cork-Oak 
 Tree (Quercus Suber), x 120. Exogen. 
 
 The large holes seen in this drawing represent the trans- 
 verse sections of the ducts of this wood; the other parts 
 represent the woody parenchymatous cells, placed amidst the 
 ordinary prosenchymatous tissue of the wood. The large 
 holes give the woods belonging to this genus, which may be 
 represented by this drawing, a distinctive character from those 
 of most of our British woods, their grain generally being 
 much closer (see figs. 68, 69, 70, &c.) . 
 
 Oak is an extremely durable wood, and is, or rather was, 
 largely used in ship-building &c. 
 
 Fig. 62. Longitudinal Section of Honduras Mahogany 
 (Swietenia Mahagoni), x80. Exogen. 
 
 The ducts of this wood seem to be extremely large and 
 very loose in structure. They contain a large quantity of 
 resin, part of which, as left in the duct, may be seen on 
 referring to the drawing. The ordinary prosenchymatous 
 tissue is also of a rather looser structure than is generally 
 found in most other woods. 
 
Mg. 63, 
 
 Fig. 64 
 
 Jao. H.Maztrn. ad nat. dd. . 
 
 London John Van. Voorst MDCCCLXX 
 
MICROSCOPIC OBJECTS. 32 
 
 Fig. 63. Transverse Section of Honduras Mahogany 
 (Swietenia Mahagoni) , x 80. Exogen. 
 
 This section also shows the resin in its natural position 
 in the ducts. The transverse sections of the ducts and the 
 prosenchymatous tissue also exhibit nearly as open an ap- 
 pearance as seen in the longitudinal sections. 
 
 This wood is largely used in commerce. 
 
 Fig. 64. Longitudinal Section of Alder-wood ( Alnus 
 glutinosa), x 200. Exogen. 
 
 The medullary cells are of a very dark and close structure 
 in this wood, which will be seen on referring to the drawing ; 
 the prosenchymatous tissue is also of a close nature ; but to 
 make up for this, and to allow the juices of the tree to circu- 
 late freely, it has rather large ducts. 
 
 The wood is extremely useful, having the property of re- 
 maining nearly intact for many years under water. It is 
 therefore used for piles &c ; it is also used for the produc- 
 tion of charcoal &c. 
 
Fig. 65 
 
 Fig. 66 
 
 JnaH.Martm, al nat.deL. 
 
 Loa&m Join. Van Tcorst. MDCCCLXX. 
 
 Dick.iu.6on. Imp. 
 
MICROSCOPIC OBJECTS. 33 
 
 Fig. 65. Transverse Section of Alder-wood (Alnus 
 glutinosa) , x 200. Exogen. 
 
 The large ducts of this wood were mentioned in the pre- 
 ceding description; their transverse sections are well illus- 
 trated by this drawing. The smaller holes represent the 
 transverse sections of the ordinary prosenchyrnatous tissue; 
 there are also a few parenchymatous cells. The dark lines 
 represent the transverse sections of the medullary cells. 
 
 Fig. 66. Longitudinal Section of the Wood of the Willow 
 (Salix alba), x 120. Exogen. 
 
 This wood also has rather large ducts ; and in this case they 
 are very numerous. The ordinary prosenchymatous tissue is 
 rather closely packed, and the medullary cells are small and 
 few in number. This wood being of such a light, open, yet 
 strong and durable nature, makes it extremely useful where 
 great elasticity and lightness are required, such as in boat- 
 building, cooperage, basket-manufacture, &c. A valuable 
 tonic medicine called Salicine is extracted from the bark of 
 this wood; its properties are nearly allied to those of 
 quinine. 
 
 Fig. 10 represents a more highly magnified section of this 
 wood. 
 
67 
 
 . 68 
 
 Jho.H.Mita. admt del 
 
 London., Jotu. I/an Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 34 
 
 Fig. 67. Transverse Section of the Wood of the Willow 
 (Salixalba), x 120. Exogen. 
 
 The transverse section of this wood shows the very large 
 number of ducts that the wood contains. The smaller holes 
 represent the transverse sections of the ordinary prosenchy- 
 matous cells,, and the dark lines represent the transverse 
 sections of the medullary cells. As was mentioned at fig. 66, 
 this wood is remarkable for its extreme elasticity, the cause 
 of which is evident on referring to the drawing; the ducts 
 being numerous and large, allow for the extra pressure of the 
 prosenchymatous, or woody fibre, when the wood is bent. 
 Both the ducts and the woody fibre are also greatly strength- 
 ened by the small yet strong and frequently occurring medul- 
 lary cells. 
 
 Fig. 68. Longitudinal Section of Norfolk-Island Pine 
 (Araucaria excelsa), x 120. N. O. Coniferse. 
 
 This wood has been chosen chiefly to illustrate that of the 
 N. O. Coniferse, which, unlike most other woods, is destitute 
 of the ducts. The transverse sections of the prosenchymatous 
 cells are generally of an hexagonal form ; while the longitu- 
 dinal sections exhibit, under a moderate power, glands or pits 
 seated in the prosenchymatous or woody cells, as shown in 
 fig. 14. The large holes in the drawing of this wood repre- 
 sent the transverse sections of the medullary cells. 
 
 Many of the cuticles of the leaves of the Coniferse exhibit 
 interesting structures, an instance of which was shown in 
 fig. 24. 
 
Fig. 69< 
 
 Fig. 70 
 
 ad aatdel. 
 
 London Jolm. "Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 35 
 
 Fig. 69. Transverse Section of the Wood of the Norfolk-Island 
 Pine (Araucaria excelsa), x 120. N. O. Coniferse. 
 
 This network, consisting of the transverse sections of the 
 woody tissue, exhibits the hexagonal form which the cells 
 have taken from the even pressure exerted on all sides. The 
 dark lines represent the transverse sections of the medullary 
 cells. 
 
 The members of this natural order are of great service in 
 the arts and manufactures, their woods being largely used in 
 commerce ; and most of the species secrete resin, turpentine, 
 &c. Pinus larix (the Larch) yields Venetian turpentine. 
 The Cedar of Lebanon also belongs to this natural order. 
 
 Fig. 70. Longitudinal Section of the Wood of the English 
 Yew (Taxus baccata), x 120. N. O. Coniferse. 
 
 The texture of this wood is also very close and hard, the 
 prosenchymatous cells being even smaller than those of the 
 Norfolk-Island Pine; the medullary cells are also close in 
 structure, although rather numerous. 
 
 The fine grain and beautiful shading of some parts of this 
 wood make it useful in turnery and fancy woodwork. It is 
 also used for bows. 
 
 Articles made from this wood are exempt from the ravages 
 of insects &c. 
 
 F2 
 
g. 71 
 
 Fig. 72, 
 
 Jhn.H. Martin., ad a . id.. 
 
 london. Jo'hn.'Vm Voorst. MDCCCLXX. 
 
 Dickmeotn., Im 
 
MICROSCOPIC OBJECTS. 36 
 
 Fig. 71. Transverse Section of Malacca Pepper Stem 
 (Piper nigrum), x 40. 
 
 The section of this stem has been taken the better to illus- 
 trate some of the remarks made in the description of fig. 59. 
 Being a section of an exogenous stem, it has the central 
 cellular pith, the medullary rays proceeding from the pith to 
 the bark or outer skin, and also rays of the ordinary prosen- 
 chymatous or woody tissue. The five larger holes are trans- 
 verse sections of the ducts. 
 
 Fig. 72. Transverse Section of the Stem of the Cocoa-nut 
 Palm (Cocos nucifera) , x 20. Endogen. 
 
 Endogenous plants may be distinguished from Exogens by 
 their stems being destitute of medullary cells and concentric 
 layers of annual woody growth, also by their stems being 
 almost composed of cellular tissue although in some plants 
 the vascular tissue is largely represented, as, for instance, in 
 this Palm, the oval parts in the drawing representing the 
 vascular tissue seated in a mass of parenchymatous cells. 
 The large dotted ducts which are generally found in the 
 exogenous woods are also absent. Many Endogens are met 
 with in which the centre of the stem is entirely absent, as in 
 the Grasses &c. 
 
 This section is best seen mounted in fluid. 
 
Fig. 
 
 Fig. 74 
 
 London, Jbfca.TGra.Vi-.Bsr MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 37 
 
 Fig. 73. Transverse Section of the Stem of Sarsaparilla 
 (Smilax Sarsaparilla), x 40. Endogen. 
 
 The drawing illustrates another endogenous stem, as seen 
 in the common Sarsaparilla of commerce. The clusters of 
 large holes represent the bundles of vascular tissue, and the 
 network the parenchymatous or cellular tissue. The Sarsa- 
 parilla plant belongs to the N. O. Smilacese a small Natural 
 Order, but one containing some valuable plants. 
 
 Fig. 74. Transverse Section of Pilea smilacifolia, x 40. 
 Exogen. 
 
 This section of the pith of one of the exogenous plants of 
 the Natural Order Urticacese has been taken to show the 
 transformation of many of the parenchymatous cells, by a 
 process of secondary deposit, into thickened cells having a 
 tendency to form wood, woody fibre, or prosenchymatous 
 cells, as will be seen in observing this and other herbaceous 
 plants. 
 
Fig. 75 
 
 Fig. 76 
 
 ad.-nat.del 
 
 London, JolmVan-Toorst MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 38 
 
 Fig. 75. Transverse Section of the Stem of a Lycopodium 
 (Lycopodium iiisequalifolium) , x 20. Acrogen. 
 
 A section of this club-moss has been figured to illustrate 
 the structure of an acrogenous stem, as differing from the 
 exogenous and endogenous stems shown in figs. 59, 71, 72, 
 73, &c. 
 
 On the outer part of the stem a thin layer of cells, which 
 have been thickened by secondary deposit and dotted, will 
 be seen and inside this formation a loose layer of cellular 
 tissue, surrounding bundles of scalariform tissue. For another 
 example of an acrogenous stem see fig. 11. Lycopodiums 
 appear to be closely allied to some Ferns as regards the 
 position &c. of their seed-vessels. The creeping Selayinella 
 of our Wardian cases belongs to this Natural Order. 
 
 The transverse and other sections of this plant may be 
 mounted in fluid or glycerine jelly. 
 
 Fig. 76. Fructification of a Fern (Polypodium vulgare) , 
 
 x40. 
 
 From the various species of British and foreign Ferns and 
 Mosses some of the most beautiful and instructive objects 
 may be taken by the microscopist and botanist for their 
 cabinets. The present drawing shows the naked sori for 
 which this genus of Ferris is remarkable, as the sori, or groups 
 of seed-vessels as they may be called, of Ferns are generally 
 covered with a cellular membrane or skin of different shapes. 
 Most species have a reniform or kidney-shaped covering, or 
 indusium as it is called (see fig. 77). The masses of sori 
 generally occur on the back of the fertile fronds, although in 
 some cases they are found on the margins, as in the Maiden- 
 hair Fern (Adiantum); and sometimes they are placed alone 
 upon stalks, as in the Osmund a Fern (fig. 79), in which case 
 they form capsules. 
 
 This object is best mounted in a dry opaque cell. 
 
Fig. 77 
 
 
 Fig. 
 
 a.i nat del 
 
 London.. Jolin. "Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 77. Fructification of the Male Fern (Lastrea Filix- 
 Mas), x25. 
 
 In this drawing the reniform indusium or covering for the 
 sori will be well seen. The sporanges situated under the indu- 
 sium have a small stalk, differing in length according to the 
 species of Fern ; by this they are slightly fixed to the surface 
 of the frond. For their shape &c. when much magnified, see 
 fig. 78. 
 
 On the stipes or stalks of the fronds of Ferns beautiful- 
 shaped scales often occur ; for an example see fig. 26. 
 
 Fig. 78. Spores and Spore-cases of the Brake Fern (Pteris 
 aquilina), x 120. 
 
 This object, as seen under the parabolic reflector, exhibits 
 the sporanges or spore-cases in the act of discharging the 
 spores. Around the outer side of the cases a ring will be 
 noticed, which is called the annulus. This, being very 
 elastic, when the sporange arrives at maturity breaks at a 
 part of the circumference, and by its elasticity ruptures the 
 case, and scatters the spores around. 
 
 Some of these, dropping on a smooth damp surface, grow 
 into a kind of minute leaf, called the prothallus. In this 
 prothallus, at an early period of its growth, appear the repro- 
 ductive organs. The frond is then fertilized, and grows until 
 the sori appear, and when these are ripened the frond dies off. 
 Such, in a few words, is the life and growth of Ferns. 
 
 The sporanges and spores are best mounted in balsam. 
 
Fig. 79 
 
 Fig. SO 
 
 JnaH.Maifea ad_nat del 
 
 London. JoiiiVari. Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 40 
 
 Fig. 79. Capsules of the Flowering Fern or King of Ferns 
 (Osmunda regalis) , x 20. 
 
 The spore-cases or capsules of this are entirely different 
 from those of most other Ferns,, being of a subglobose shape 
 and opening vertically. 
 
 The capsules are borne on the fertile fronds in clusters, 
 placed upon stalks. 
 
 Fig. 80. Spores of an Equisetum (Equisetum fluviatile), 
 
 x!20. 
 
 The spores of the Equisetacese are remarkable for their 
 hygrometrical properties, which cause the elaters or curved 
 fibres to curl up when subjected to the influence of moisture. 
 Some of the spores in the drawing will be noticed in the act 
 of curling. In fact they are so sensitive to the least mois- 
 ture, that I doubt not, with observation, this object might 
 be used as a natural barometer. 
 
 The siliceous cuticles of the different species of Equisetum 
 are also good objects, when mounted in balsam, for the pola- 
 riscope. 
 
 The spores are best seen when mounted dry. 
 
. 
 
Fig. 
 
 Fig. 82, 
 
 HA* del 
 
 London. JoLtt Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 41 
 
 Fig. 81. Capsule of a Moss in the act of discharging its 
 Spores (Tortula subulata) , x 20. 
 
 Mosses are divided into two great sections, called Acrocarpi 
 and Pleurocarpi, Acrocarpi signifying that the capsule borne 
 on the fruit-stalk or seta terminates the moss, and Pleuro- 
 carpi that the fruit-stalk springs from the side of the stem 
 of the moss. 
 
 These groups are again divided, according to the structure 
 of the peristome, into Aploperistomi and Diploperistomi. 
 The drawing shows the single peristome (section Aploperi- 
 stomi) in the act of discharging the spores. It is drawn as 
 seen under the parabolic reflector. 
 
 The genus Tortula has been so called from the spirally 
 twisted peristome, which will be 'seen in the drawing ; it is 
 the most common of all the genera of Mosses, and the species 
 are chiefly found on walls, very rarely on banks, trees, &c. 
 
 The object may be mounted in balsam. 
 
 Fig. 82. Capsule and Peristome of a Moss : opaque view 
 (Funaria hygrometrica) , x 20. 
 
 The division Diploperistomi is represented by this drawing, 
 although a better view of the double peristome will be seen 
 in fig. 84. The seta of this Moss has the property of twisting 
 itself upon the application of water, from which property it 
 has gained the specific name of hygrometrica. It is one of 
 our commonest Mosses, being found on the top of nearly all 
 old walls &c. ; it is also very commonly found growing where 
 a fire has lately deposited wood-ashes. A longitudinal sec- 
 tion of the young green capsule of this Moss is a good subject 
 to show the position &c. of the columella (see fig. 83) . 
 
 The ripe capsule, as shown in the drawing, is best mounted 
 in a dry opaque cell. 
 
Fig. S3 
 
 Fig. 
 
 JruHMaitifl. ad nat dd. 
 
 Die It me on. 
 
 London John. Van "Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 42 
 
 Fig. 83. Section of a young Capsule of a Moss, showing 
 Columella fyc. (Funaria hygrometrica), x 50. 
 
 Any quantity of the young green capsules of this Moss may 
 be collected for examination in the months of February and 
 March, as they then show the columella, seen in the centre 
 of the drawing of the young capsule. Around this columella 
 are clustered the spores when the capsule is mature ; at pre- 
 sent the spores are undeveloped. The best plan of mounting 
 this object is as follows : take a young capsule, plunge it into 
 a small quantity of liquid India-rubber, let it dry until a slice 
 can be taken, then slice with a fine scraper in the direction 
 from the seta to the operculum, wash in alcohol, and mount 
 in fluid or glycerine-jelly. 
 
 Fig. 84. Dissections of a Moss, showing the Peristome, Oper- 
 culum, and Annulus (Funaria hygrometrica), x 20. 
 
 These dissections, together with figs. 81, 82, 83, and 85, 
 comprise the chief parts of Mosses as named in a botanical 
 description of any species. The larger piece in the drawing 
 has 16 teeth and 16 cilia (not all visible), which compose 
 the two rows, and are both included under the title of the 
 peristome. The largest round piece is called the operculum, 
 or cap. This in all cases covers the peristome with its 
 delicate teeth, until the spores in the capsule are mature, 
 when it falls off, and in the act often loosens the annulus, 
 the small circle shown in the drawing. If the annulus is 
 not thrown off then, it soon follows the operculum, and no 
 doubt, by its elasticity, aids greatly in scattering the spores 
 around the parent moss ; the hygrometrical properties of 
 many of the setse of Mosses also assist the other organs in 
 this important provision for the increase of the species. 
 
 The objects are best mounted in fluid. 
 
Fig. 85 
 
 Fig. 86 
 
 ad -oat del 
 
 London John. Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 43 
 
 Fig. 85. Reproductive Organs of Moss (Bryum hornum), 
 
 x60. 
 
 The reproductive organs, the antheridia and archegonia, 
 of Mosses answer somewhat in their functions to the stamens 
 and pistil of the flowering plants (see fig. 44) , although of course 
 there is a difference in their mode of action. The antheridia, 
 or male organs, are generally of an oblong-oval shape (see 
 the drawing), and the archegonia, or female organs, flask- 
 shaped ; the latter are developed by successive changes into a 
 capsule borne on a seta or stalk, and containing in its centre 
 a columella surrounded by spores. 
 
 The study of the fructifying organs of Mosses will be found 
 exceedingly interesting ; and in the spring of the year they 
 are not difficult to find, at least to any person having a will 
 to do so. 
 
 They may be mounted in many ways ; but I prefer fluid. 
 
 Fig. 86. Capsule of Two-horned Scale-Moss (Jungermannia 
 bicuspidata) , x30. 
 
 The Jungermannise seem to form the link between the 
 Mosses and the Lichens, although they differ from each in 
 many respects. The chief characteristics of the Junger- 
 mannise are the leaves being bifarious, and often possessing 
 stipule-like bodies called amphigastria (see fig. 87) , and spo- 
 ranges bursting by four valves. They are destitute of a 
 columella, but possess curious bodies, called elaters, mixed 
 with the spores ; these elaters are like two springs joined, in 
 their opposite spiral direction. They will be noticed in the 
 drawing, also the four valves of the capsule or sporange. 
 
 The capsules, elaters, &c. are best mounted in balsam. 
 
Fig. 8 '/ 
 
 Fig. 
 
 JjiaH .Ifn&n., ad nai del 
 
 London. John. Var. Voorst MDCCCLJOC. 
 
 Dickinson., ' 
 
MICROSCOPIC OBJECTS. 44 
 
 Fig. S7.Tubercled Scale-Moss (Frullania dilatata), x20. 
 
 This Scale-moss belongs to the Jungermannise, but, unlike 
 the preceding genus, the capsules are sessile ; that is, seated 
 close to the stem. The capsules are absent in this figure, as 
 it has been drawn chiefly to illustrate the bifarious leaves, and 
 the stipule-like bodies called amphigastria, which bodies, it 
 will be noticed, are placed in rows on each side of the stem. 
 This plant is common on the bark of many trees, although it 
 may not often be noticed by casual observers on account of 
 its being of a brown colour. 
 
 It is best when mounted in fluid or glycerine-jelly. 
 
 Fig. 88. Yellow Wall-Lichen (Parmelia parietina) , x 20. 
 
 This is one of the commonest of our British Lichens, It is 
 found chiefly on walls, palings, &c., and may be known by 
 its yellow colour (although it is often of a greyish tint when 
 growing in the shade) and by its having also large yellow 
 apothecia, or cups, of which magnified views are given in this 
 drawing; the other part is called the thallus. This part, 
 although different in shape, would slightly answer to the young 
 fronds of ferns, it containing within its structure all the re- 
 quisite organs for its further propagation. The organs of 
 fructification are similar to those of the Fungi. 
 
 Although common, they are plants but little studied in 
 fact, even less so than Mosses. Here microscopists will find 
 a good and useful field for their labours of research. 
 
 Most of the Lichens, when required for the determination 
 of their species only, are best mounted in a dry opaque cell ; 
 when their parts are wanted, they are best mounted in fluid 
 or balsam. 
 
Fig. 89 
 
 Fig. 90 
 
 ad nat.del 
 
 London Join. "Via Voorst. MDCCCJ2OC. 
 
MICROSCOPIC OBJECTS. 45 
 
 Fig. 89. Transverse Section of the Apothecia of a Lichen 
 (Parmelia parietina), x 200. 
 
 It will be seen from this drawing that, although unlike in 
 their general outward appearance. Lichens much resemble the 
 Fungi in many of their organs. The frond, or, as it is called 
 in this case, the thallus, is composed of four parts, which the 
 drawing represents, the top consisting of a thin layer of the 
 coloration- cells ; next to this are the sacs or thecae, containing 
 the spores, and next to these are the gonidia or globular 
 bodies. These bodies appear to answer many of the purposes 
 of the buds of the higher flowering plants, and are, perhaps, 
 the most useful in its propagation. Next to these are the 
 filaments, some of which answer the purpose of roots; and 
 amidst the upper layers the gonidia are produced. 
 
 A section of the apothecia should be cut with a fine scalpel, 
 soaked in alcohol for a minute, and then taken out and dried 
 under pressure, and mounted in balsam as usual, but without 
 heat. 
 
 Fig. 90. Transverse Section of a Fungus, so-called Scarlet 
 Cup-Moss (Peziza coccinea), x 100. 
 
 The drawing of this Fungus has been taken to show the 
 difference between the parts and those of a section of a 
 Lichen as represented in the preceding figure. The gonidia 
 are wanting, and the coloration-cells, instead of being only a 
 superficial layer, as in the section of the Parmelia, are mixed 
 with the asci. Beneath these is the mycelium, consisting, in 
 this case, of a number of fine felted filaments, producing a 
 leathery kind of thallus (mycelium) . It will be noticed, from 
 these slight descriptions, that in their organic parts Lichens 
 are not unlike the Fungi. 
 
 Sections may be treated in the same manner, and mounted 
 in balsam, although in many cases I prefer fluid. 
 
Fig. 91 
 
 Fig. 92. 
 
 ad HA* dd. 
 
 London, John. Van Voorst MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 46 
 
 Fig. 91. Bramble-leaf Brand (Aregma bulbosum), x 350. 
 
 This, together with many other objects mentioned in this 
 book, are not at all uncommon, and for that very reason I 
 have taken it ; so that it may be seen that the rarest objects 
 are not always the most beautiful, nor yet even the most 
 instructive. 
 
 The reader has, no doubt, often noticed in the autumn that 
 the leaves of the Bramble are spotted with small black dots ; 
 these dots, when magnified, resolve themselves into a number 
 of oblong spores seated on stalks. These spores appear to 
 be divided into three or more cells, and they may be taken 
 as an example of the general structure of the brands, which, 
 although not so destructive as the Rusts &c., still in some 
 cases do much harm to the farmer's crops. 
 
 The best plan of mounting these brands is to cut a very 
 thin section through the leaf containing the brand, and then 
 to mount it in a shallow cell in the essential oil of lemon. 
 
 Fig. 92. Cluster-cups on the Leaf of the Pilewort (^Ecidium 
 Ranunculacearum) , x 20. 
 
 Cluster- cups are another kind of microscopic Fungi, also 
 common on many of our British plants ; for instance, on the 
 Common Spurge (Euphorbia amygdaloides) of our hedges 
 they will be noticed in large numbers. To make out their 
 structure, the leaves on which they grow may have sections 
 cut through them, and also the cuticle of the leaf may be 
 torn off. The spores are large in most of the species, and 
 when young will be seen seated in the cups, or, as they are 
 called, the peridia. 
 
 These objects, when entire, are best when mounted dry ; 
 but the sections &c. are best mounted in fluid. I prefer oil 
 of lemon. 
 

 Sf v t \ m ,4- 
 
 ^4rtxf 
 
 Fig. 93 
 
 Fig. 94 
 
 London. John. Van. Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 47 
 
 Fig. 93. Mould from a Decayed Leaf of Begonia (Botrytis 
 vera), x 40. 
 
 Another kind of microscopic Fungi are the moulds, of 
 which this species is an example ; they are chiefly found on 
 decaying vegetable substances. 
 
 The disease called the potato-blight is a mould, and be- 
 longs to this genus. Without doubt the spores of many of 
 the moulds enter the stomata of the leaves of plants, and are 
 thus carried with the sap into all its parts; and if there is 
 any inherent weakness which would be favourable to their 
 growth, they increase accordingly. That the spores of Fungi 
 thus enter into the circulation of plants may be shown by 
 mould being found in the interior of apples &c. Moulds and 
 various Fungi may be cultivated in a damp atmosphere, pro- 
 duced by covering damp sand or earth with a bell glass, such 
 as those used by gardeners, the sand being kept constantly 
 moist. 
 
 The different moulds show best when mounted in a deep 
 dry cell. 
 
 Fig. 94. A Species of Confervoid Algce (Spirogyra decimina), 
 
 x!20. 
 
 Of this species of Conferva, collected at Hollingbourne, 
 near Maidstone, the spiral bands are two, crossing each other 
 so as to present the appearance of a repetition of the letter X 
 joined together; and from this characteristic it is that the 
 species is named. The genus also is named Spirogyra from 
 the spiral bands which are always found, generally numbering 
 from one to four, according to the species. Some of the 
 species being rather common, and more particularly their 
 remarkable appearance, have caused them to be well studied. 
 The process of conjugation of the Confervse may be well seen 
 in ripe specimens of this genus. 
 
 It is best mounted in a suitable fluid. 
 
Fig. 95 
 
 .Figr. 96 
 
 adaai del. 
 
 London. 
 
 MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 48 
 
 Fig. 95. A Species of Confervoid Alga (Batrachospermum 
 moniliforme), x 60. 
 
 This species may be considered one of the most beautiful 
 of all the Confervoid Algse. It is found in clear and slow- 
 running streams. The colour is generally green, yellow, or 
 red ; and it may be distinguished by its fine sprays, somewhat 
 resembling one of our common red Seaweeds (PLocamium 
 coccineum). The tufts of chains of the oval spores occur in 
 whorls at intervals in the stem of the plant. 
 
 The object is best mounted in fluid. 
 
 Fig. 96. A Species of Conferva (Prasiola calophylla), x 100. 
 
 The chief character of this rare form of Conferva is that 
 the cells are placed in groups of four, in regular lines with 
 intercellular walls. The increase of the plant appears to be 
 by the solution or destruction of the filaments by the process 
 of decay, when the cells, which seem to be the spores also, 
 are left free, and so by their growth increase the species. 
 The reproduction of this Conferva appears to have been at 
 present little studied. 
 
 The object is best when mounted in fluid. 
 
Fig. 97- 
 
 Fig. 98. 
 
 ad.rjrf.del 
 
 London. John. "Via. "Voorst. MDCCCLXX 
 
MICROSCOPIC OBJECTS. 49 
 
 Fig. 97. A Species of Confervoid Alga (Volvox globator), 
 
 x40. 
 
 It is only within the last few years that this microscopic 
 organism has been thoroughly examined, and found to be 
 one of the Confervoid Algse, before which time it was thought 
 to be an infusorial animalcule. On the examination of fresh 
 specimens (which may often be procured in pools, on open 
 heaths, fields, &c., and which appear to the naked eye as 
 minute globular bodies, moving with a rolling motion) under 
 a low power, say 1 inch, the cause of motion will be seen to 
 consist in a multitude of minute hairs (or cilia, as they are 
 called) with which the bodies are studded; these act as oars. 
 In the interior a number of small green bodies will be seen ; 
 these are the young volvoces, and, on the rupture of the mem- 
 branous sac of the parent plant, escape, grow, and increase. 
 They are preserved with difficulty so as to show the cilia. 
 They appear to keep tolerably well when mounted in a shallow 
 cell in weak alcohol and water. 
 
 Fig. 98. A Diatom in its Natural State on a Conferva 
 (Diatoma vulgare), x 200. 
 
 Diatoms belong to the Confervoid Algse, but are remark- 
 able in consisting of an extremely brittle structure composed 
 of silex. They are found in nearly all places where there is 
 water, either growing on other plants, or forming a dense 
 mass at the bottom. Their colour, being generally of a 
 yellowish brown, makes them very distinguishable when oc- 
 curring at the bottom of ponds &c. The species are very 
 numerous, and they form an order of plants that have been 
 much studied perhaps a little too much so, to the exclusion 
 of other minute and remarkable forms of vegetable and 
 animal life. 
 
 If they are to be preserved in their natural state, they are 
 best mounted in a shallow cell in fluid; but the siliceous 
 valves or frustules are generally cleaned by boiling in nitric 
 acid for a short time, and the species separated by taking 
 advantage of their different specific gravities. They may 
 then be mounted dry or in Canada balsam as usual. 
 
Fig. 99. 
 
 Fig. 100. 
 
 London Jo}m Van Voorst. MDCCCLXX. 
 
 In 
 
MICROSCOPIC OBJECTS. 50 
 
 Fig. 99. A Species of Desmid (Closterium Leibleinii), x 120. 
 
 Desmids also belong to the Confervoid Algse ; they may 
 usually be distinguished from Diatoms, in their natural state, 
 by their green colour. They, as well as Diatoms, occur in 
 large numbers in ponds that have an exposed situation, 
 although they may be found in nearly all standing water. 
 The great variety and beauty of their forms have caused them 
 to be much studied. 
 
 The frustules consist of a cellulose coat or membrane, enclo- 
 sing the cell- contents. Each frustule forms only a single cell, 
 which may be demonstrated by fracturing one end, when all 
 the cell-contents will escape from the frustule, which of course 
 would not be the case if the apparent division in each frustule 
 were real (see fig. 100) . These plants, like the Diatoms, may 
 often be separated from the extraneous matter by the action 
 of light, they always being found to travel towards the lightest 
 part of their habitations. 
 
 They may be mounted in a shallow cell, in camphor-water 
 although it is difficult, if not impossible, to preserve them 
 with their colours &c. uninjured. 
 
 Fig. 100. A Species of Desmid (Micrasterias denticulata) , 
 
 x!70. 
 
 This, like the preceding species of Desmid, is tolerably 
 common. In the centre of the frustule there will be noticed 
 an apparent transverse division, as mentioned at fig. 99 ; but 
 the appearance is delusive, as will be seen on examination. 
 That Desmids have the power of locomotion is apparent to 
 all students of microscopy ; but how they move is at present 
 a mystery. Their reproduction occurs in three or four ways 
 by cell-division (which is the commonest mode), by spores, 
 and by ciliated zoospores. The last mode of reproduction is 
 exceedingly interesting ; it may often be noticed by examina- 
 tion under the miroscope, more especially in the spring and 
 summer months. The Desmid appears to have its cell-con- 
 tents contracted, and within this contraction the really active 
 zoospores will be seen in constant motion. The examination 
 of many species will amply repay the trouble ; for when this 
 mode of reproduction has been seen, the time and trouble 
 have been well spent. 
 
Fig. 101. 
 
 Fig. 102,. 
 
 . ad. jut. dd 
 
 London. Jofcn Van. Voorst. 
 
MICROSCOPIC OBJECTS. 51 
 
 Fig. 101. An Infusorial Animalcule (Amoeba diffluens), 
 
 x200. 
 
 The best description of the Amceba would be, (( a simple 
 mass of organic animal matter ; " for in fact, as to shape, it 
 cannot be described, being constantly changing. By old authors 
 it was well called " Proteus." It may be found in nearly all 
 water that has a quantity of decaying matter, such as leaves, 
 in it ; but the best, and a certain place in which to find it, is 
 in the slimy and frothy scum which appears on many ponds 
 in the spring and summer. The form of the animal when it 
 is at rest, which is rarely the case, is globular. It may be 
 considered one of the lowest forms of animal life. 
 
 It may be mounted; but objects like this are always best 
 seen when alive. They, together with many other kinds of 
 animalcules, may be kept in suitable glass jars. 
 
 Fig. 102. Foraminif era from Chalk, x 100. 
 
 This chalk, taken from Detling, near Maidstone, is tole- 
 rably rich in fossil Foraminifera (Rotalinae, Textularise, 
 Globigerinse, &c.) intermixed with a large number of the re- 
 markable disk-like bodies called crystalloids. 
 
 A deposit, nearly like chalk in its constituents, is now being 
 deposited in the bed of the Atlantic. The method of prepa- 
 ration is, to take a small piece of chalk and scrape it fine, or, 
 what is better, a small quantity of the natural powder found 
 at the base of the chalk-cliffs ; put this into a 6- or 8-ounce 
 phial and fill with water ; keep on adding fresh water as long 
 as it comes away of a milky tint ; the deposit will then be 
 found to consist of minute shells &c. The waste water is 
 best removed with a glass siphon. To mount the Foramini- 
 fera, a small quantity should be soaked in turpentine for a 
 short time, and then mounted in balsam as usual. If any air- 
 bubbles occur, they will disappear in the course of a few days. 
 
 H2 
 
Fia. 103. 
 
 Fig. 104. 
 
 JnaH.Mwtm.. ii an del 
 
 London John Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 52 
 
 Fig. 103. Foraminif era from the Adriatic Sea, x 40. 
 
 The Foraminifera in this drawing are much smaller than 
 those taken from the Levant end of the Mediterranean Sea, 
 which may possibly be accounted for by the action of the 
 storms in that region ; for if the shells were larger no doubt 
 they would be deposited in greater abundance. The Fora- 
 minifera are thought by many authors to belong to a family 
 of which the Amoeba (fig. 101) may be taken as an example. 
 The soft body of the Foraminifera may be separated from its 
 shell by the action of dilute muriatic acid say, one drop of 
 acid to a teaspoonful of water. 
 
 The best way of separating the shells from the surrounding 
 sand &c. is to float them in water, when the sand sinks and 
 the shells are left on the surface. 
 
 They may then be mounted in the way recommended under 
 fig. 102; or they may be put up in a dry opaque cell. 
 
 Fig. 104. Foraminifera from the Levant, x 20. 
 
 These species of Foraminifera are much larger than those 
 in fig. 103, which may possibly be accounted for as remarked 
 in the preceding description. In the shells of the Foramini- 
 fera, Polycystina, &c. numerous small holes will be noticed ; 
 it is from these holes that the family has been named (Latin, 
 foramen, a hole). The holes will be especially noticed in 
 the shells of the Polycystina represented in fig. 105, and in 
 all the common species of the Foraminifera of the chalk for- 
 mation &c. 
 
 Many forms of the recent Foraminifera may be obtained 
 from dredgings at most of our sea-coast towns ; but the more 
 beautiful forms are generally obtained from deeper water than 
 is found in our English Channel. 
 
Fig. 105. 
 
 J?ig. 106. 
 
 Jr.,.r,H.Maitin.. ad nat del. 
 
 London,. John. Van Voorst. MDCCCIXJC. 
 
MICROSCOPIC OBJECTS. 53 
 
 Fig. 105. Polycystina : Fossil Shells from Barbadoes, x 100. 
 
 These beautiful shells are closely related in their classifi- 
 cation to the Foraminifera, being grouped with them under 
 the head of Rhizopoda, which may be described as consisting 
 of organic structureless bodies, as in Amoeba. But in the 
 Foraminifera, Polycystina, &c. these bodies are confined in 
 a certain degree within their shell, although they send out, 
 through the small holes in the shells, retractile processes, 
 which answer in their functions to the legs of insects &c., 
 being organs of locomotion. The species are mostly fossil, 
 and are chiefly found in the West-Indian Islands &c. The 
 remarkable beauties of these forms might well be taken 
 advantage of, as patterns for jewellery and other manufac- 
 tured articles. They, like the Foraminifera, may be mounted 
 in balsam, or in a dry opaque cell &c. However they be 
 mounted, they will well repay the trouble bestowed on them. 
 
 Fig. 106. Section of Sponge (Spongia usitatissima), x 120. 
 
 On examining this drawing of the horny fibres of the 
 Common Sponge, the reason of their retaining so much water 
 will be evident. The fibres will be noticed to be of a very 
 elastic structure, which, by compression, discharge the water, 
 and on their reflex action absorb it. By the capillary action 
 of the numerous fibres they also retain the water until the 
 sponge is pressed. Sponges, in their living state, are covered 
 with an amorphous jelly-like substance similar to that of the 
 Amoeba (fig. 101) j and if this substance be examined under 
 the microscope, its motions will be found nearly identical. 
 Sponges are mostly marine animals; but there are a few 
 freshwater species to be found in England. 
 
 No doubt sponges live by absorbing their prey, in the same 
 manner as the Amoeba. Sections are best mounted in fluid. 
 
Fig. 107. 
 
 Fig. 10 S. 
 
 Jr.o.KMMtm., *d uai del 
 
 London... Join. Van. Voorst MDCCdXT 
 
MICROSCOPIC OBJECTS. 54 
 
 Fig. 107. Spicula and Gemmules of Sponge (GeodiaBarreta), 
 
 x200. 
 
 Most sponges contain siliceous bodies called spicula (see 
 drawing) . They are of various forms ; but the most general 
 are acicular or needle-shaped, and stellate or star-shaped. 
 Most of the siliceous sponges also contain reproductive bodies 
 called gemmules ; they are the round masses in the drawing. 
 
 Sponges also increase by ordinary ova, as in the case of 
 other animals. To separate the spicula, gemmules, &c. of 
 the siliceous sponges from the surrounding extraneous mass, 
 they must be boiled for a short time in nitric or sulphuric 
 acid and well washed in warm and cold water, then dried, 
 soaked in turpentine, and mounted in Canada balsam, as 
 usual ; or they may be mounted dry. 
 
 Fig. 108. Spicula of Gorgonise : mixed Species, x 100. 
 
 The spicula of the Gorgonia, or, as they are popularly 
 called, Sea-fans, are beautiful objects when seen under the 
 parabolic reflector, from which this drawing is taken. The 
 spicula are found imbedded in the body of the animal. There 
 are many species, three or four of which are British. 
 
 The method of preparation is to boil the animal, or a por- 
 tion of it, in diluted potassa fusa until the mass breaks up by 
 tiie action of the fluid on the horny matter, when the deposit 
 may be removed and re-boiled for a short time in some fresh 
 potassa ; then well wash in warm and cold water, dry, soak in 
 turpentine, and mount in balsam. They may also be mounted 
 in a dry opaque cell. 
 
Fig. 109. 
 
 Fig. 110. 
 
 London. John. "Via Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 55 
 
 Fig. 109. A Zoophyte (Laomedea gelatinosa), x 20. 
 
 This is one of our commonest Zoophytes,, the specimen from 
 which the drawing was made having been collected at Hastings. 
 The zoophyte is found at low tide in the rock-pools opposite 
 Eversfield Place, and at many other places along the seaside. 
 The animal will be distinguished by its plumose appearance 
 when growing on the marine Algae, or on stones, which 
 form its favourite habitat. The description of the species is, 
 " Polypidom rooted, erect, jointed at regular intervals ; joints 
 ringed ; cells alternate, on short peduncles, campanulate ; 
 vesicles axillary, &c." The zoophyte is best when killed 
 immediately by immersion in alcohol, and then mounted in 
 alcohol and water, or in camphor-water. 
 
 Fig. 110. A Zoophyte (Plumularia setacea), x 20. 
 
 This Zoophyte, like the preceding species, is commonly 
 found on our coasts, more especially the south and south-east 
 coasts. It will often be found growing in great abundance, 
 even more so than the last species, on the underside of rocks 
 &c., and is nearly always found near, if not growing with, 
 Laomedea gelatinosa. The description of the animal is, 
 " Stem a single tube, pinnate ; pinnse alternate, one at each 
 joint ; cells very remote, campanulate ; vesicles elliptical." 
 The animal may be killed by immersion in alcohol, as men- 
 tioned with respect to Laomedea. It may also be mounted in 
 the same manner. 
 
Fig. 111. 
 
 Fig. 112. 
 
 JhaH.MaititL. ad. uat. del 
 
 Londxm. Join. Von. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 56 
 
 Fig. Ill . Spines of a Starfish (Ophiocoma rosula) , x 20. 
 
 Skeletons of any of our Starfishes may be prepared in the 
 same manner as the spines of this species have been treated 
 that is, by soaking in very dilute potassa fusa until the bony 
 structure is cleaned ; but if the fluid is made too strong, the 
 skeleton separates and becomes useless. If the spines only 
 are wanted, the alkali may be used much stronger. Although 
 common, even the ordinary Starfish (Asterias rubens) is wor- 
 thy of microscopical examination. Mixed with the spines 
 are a number of peculiarly shaped bodies called pedicellarise. 
 These are supposed to be the organs of locomotion. 
 
 The spines, pedicellarise, &c. are generally best mounted 
 dry. 
 
 Fig. .112. Spines of Spatangus, x 20. 
 
 These spines, drawn as seen under the parabolic reflector, 
 are taken from the Spatangus, a genus of Echinidse, belonging 
 to the Class Echinodermata, which comprises the Starfishes 
 &c. They show best when mounted in balsam and seen under 
 a low power, although they may be mounted in a dry opaque 
 cell and viewed under condensed reflected light. 
 
Fig. US 
 
 Fig. 11 M-. 
 
 Jno.H.Maiba. ad nat del 
 
 London. John. Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 57 
 
 Fig. 113. Transverse Section of an Echinus-spine 
 (Echinothrix petersii) , x 40. 
 
 The genus Echinus, from which the class Echinodermata 
 derives its name, has many structural beauties, both super- 
 ficial and otherwise. The spines in nearly all the species 
 furnish most beautiful objects when cut in a transverse man- 
 ner with a fine saw, then ground exceedingly thin with a file, 
 and finished on a stone. If they are wanted for the polari- 
 scope, the grinding may be coarser, and they may then be 
 mounted in balsam. The pedicellarise, sections of the shell, 
 &c. also make fine objects. 
 
 The internal structures of these animals are not less inter- 
 esting. 
 
 Fig. 114. ENTOZOON. Head of a Parasite from the Rabbit 
 (Cysticercus pisiformis) , x 30. 
 
 The parasite from which the drawing has been made 
 chiefly inhabits the alimentary canal but is sometimes met 
 with in other parts, as in the liver, where it has been found 
 in the cyst state. Another of the species (Cysticercus tenui- 
 collis] is occasionally met with in the human body. The 
 parasite is something of the shape of a bird's egg, with a 
 neck which may be elongated at pleasure ; the four projec- 
 tions in the drawing are the sucking- disks. This species 
 may be taken as an example of the internal parasites called 
 Entozoa. 
 
 Most of the species show best when mounted in balsam 
 after due preparation. 
 
JFig. 115. 
 
 Fiq. 116. 
 
 ai nat del . 
 
 London 
 
 MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 58 
 
 Fig. 115 . ENTOZOON. Trichina spiralis, from Human Muscle, 
 
 x50. 
 
 This Entozoon is particularly interesting, from the fact 
 that its presence in large numbers in pork renders the meat 
 diseased, and has produced in those who ate it an epidemic 
 called trichinosis. 
 
 On the examination of the muscle in which the parasite 
 has taken up its abode, small specks will be seen (even with 
 the naked eye) ; and on placing the part under a moderate 
 power of the microscope, the worm will be seen coiled up in 
 its oval or circular orange- coloured cyst. The worms on 
 issuing from this cyst follow the course of the voluntary 
 muscles. Some of the worms die ; but even those that are 
 left often number 50,000 to a single ounce of flesh. 
 
 The parasite is best when mounted in balsam. 
 
 Fig. 116. A Wheel- animalcule (Squamella oblonga), x 100. 
 
 The Rotatoria, or Wheel-animalcules, form a very inter- 
 esting class to all students of nature. Their chief character- 
 istics are rotatory or wheel-like organs, from which the genus 
 Rotifera and class Rotatoria derive their names. Tail-like 
 processes are present in most of the species, similar in shape 
 to the same appendage in the Cyclops (see fig. 119) ; and a 
 gizzard just below the mouth is to be seen in constant 
 motion, grinding &c., in nearly all the larger species. The 
 other parts of the alimentary canal, such as the stomach &c., 
 are short. The Rotatoria are found nearly everywhere where 
 the water is not putrid; they are very tenacious of life. 
 The most common species is Rotifer vulgaris ; this species 
 shows the ciliated wheels well. The Rotatoria are best seen 
 when examined in their natural state ; the above drawing is 
 taken directly from the living animal. 
 
 They may be mounted in alcohol and water if great care is 
 taken ; but they are difficult to keep well. 
 

Fig. 117. 
 
 Fig. 
 
 ad nat.del. 
 
 London, John. Vx Vborst MDCCCLXX. 
 
 Dickinson.. ! 
 
MICROSCOPIC OBJECTS. 59 
 
 Fig. 117. A Wheel- animalcule (Noteus quadricornis) , 
 xlOO. 
 
 This animalcule 1 found in large quantities in a large glass 
 jar that I use for the propagation of various species of minute 
 animal life. The description of the species is as follows : 
 " Carapace suborbicular, depressed., scabrous, areolate, with 
 four spines in front and two behind." This, like the preceding- 
 drawing, has been taken from the living animal. It is still 
 more difficult to mount, being rather smaller, than Squamella 
 oblonga but it is quite possible to make some good mounts 
 if a dozen or more can be put in the same cell. 
 
 They are best mounted in alcohol and water. 
 
 Fig. US. Palate of Limpet (Patella vulgata), x 40. 
 
 The palates of the Mollusca form a large series of beautiful 
 and interesting objects, of which the drawing may be taken 
 as a type. They may be easily examined in the whelk, peri- 
 winkle, snail, slug, the water- snails, such as Limnceus, Pla- 
 norbis, &c. The tongues are long ribbon-like bodies, having 
 on their surface beautiful horny (chitine) teeth, which are 
 placed upon them in various patterns, according to the 
 species. From the examination of the tongue, the family &c. 
 may often be determined. The tongue or palate is generally 
 found coiled up at the back of the head ; but this is not a 
 constant characteristic, as it is often found elsewhere in many 
 of the species. After taking it out, it must be boiled some 
 time in diluted potassa fusa, then well washed in warm water, 
 and dried under pressure ; and if wanted for the polariscope 
 or parabolic reflector, it must be soaked in turpentine and 
 mounted in balsam as usual. The above drawing is made 
 from it as seen under the parabolic reflector. 
 
Fiq. 119. 
 
 Fig, 12,0. 
 
 Jiio. H.Mitua. *d tuU del 
 
 London, Jokn. Van. Voorst. WDCCCLXX. 
 
MICROSCOPIC OBJECTS. 60 
 
 Fig. 119. Cyclops vulgaris, x 40. 
 
 This animal is also drawn from life, as seen amongst a mass 
 of Conferva. It belongs to the Entomostraca, a division of 
 the large class Crustacea. The characteristics of the species 
 are : " Foot-jaws large and strong, branched ; eye single, 
 frontal; inferior antennse simple; external ovaries two." It 
 is variable in colour. They are extremely common, so that 
 scarcely any standing water can be seen without them. They 
 vary much in size. 
 
 They may be mounted in diluted acetic acid, or in alcohol 
 and water (a shallow cell must be used) . 
 
 Fig. 120. Asparagus-Beetle (Crioceris asparagi), 
 Order Coleoptera, x 6. 
 
 This, together with the next drawing, has been taken to 
 illustrate the large order of Coleoptera or Beetles. The larvae 
 of this genus (Crioceris) are very destructive. The British 
 species, which represents the genus, lives on the asparagus. 
 The colour of the insect is tawny,, with large black bands or 
 bars on the elytra. This species, together with many of our 
 beetles, is too horny to be mounted in a transparent manner, 
 as is usual with many insects. The only way is to kill the 
 insect in boiling water, and immediately fix the legs &c. in 
 position, on white gummed paper, then cover with a cell, and, 
 after the beetle has become thoroughly dry and set, seal it as 
 nearly air-tight as possible. 
 
.Fig. 12,1. 
 
 Fig. 12,2,. 
 
 Jh.o.H.Marcia a 
 
 lor-don. Joka"Vim."tfc>orst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 61 
 
 Fig. 121. Water-weed Beetle (Helophorus gramilaris), x 12. 
 
 This little beetle may often be noticed darting about 
 amongst the weeds in ponds, and may also often be found in 
 the standing water of old water-butts, more especially if the 
 butt has been left in an exposed and sunny spot. The follow- 
 ing is a description of the order Coleoptera : ' ' Wings four ; 
 anterior (elytra) hard, coriaceous, or horny, covering the 
 posterior, which are membranous and transversely folded ; 
 mouth formed for manducation, furnished with mandibles, 
 maxillae, and palpi : metamorphosis complete." 
 
 This beetle may be mounted in a transparent manner. 
 Soak the insect in a moderately strong solution of potassa 
 fusa until it is transparent, then well wash in warm water, 
 and dry under pressure between glass slips ; soak in pure tur- 
 pentine, and mount in balsam as usual. 
 
 Fig. 122. Spiracle of Great Water-Beetle (Dytiscus mar- 
 ginalis) , x 40. 
 
 Spiracles are the breathing-pores of insects, of which this 
 drawing is an example. They supply them with the air 
 necessary for the purification of the blood, which in the case 
 of most animals passes through the mouth, but in insects it 
 is carried through tubes called tracheae, which are joined to 
 the spiracles. The spiracles of the various orders of insects 
 differ but slightly in their general form, being principally oval 
 or circular ; at their orifices hairs are generally placed to pre- 
 vent foreign substances, such as dust &c., from entering into 
 the minute ramifications of the tracheae. Spiracles are mostly 
 found on the abdomen, and also on the thorax of insects ; in 
 the Greater Water-Beetle they are found under the wings. 
 
 The mode of preparation is to soak the skin containing the 
 spiracle for a short time in diluted potassa fusa, wash in warm 
 water, dry under pressure, soak in turpentine, and mount in 
 Canada balsam. 
 
Fig. 12,8 
 
 Fig. 
 
 Jiio H.Majhn ai nat del 
 
 Londoa. Join. "Van. Vborat. 
 
MICROSCOPIC OBJECTS. 62 
 
 Fig. 123. Antenna of Cockchafer (Melolontha vulgaris), 
 
 x8. 
 
 The antennae of insects vary much as to shape, although 
 the general form is setaceous that is, having the joints 
 gradually diminishing in size from the part that joins the 
 head to the apex. Another form is the lamellate, so called 
 from a number of lamellae or plates joined at their bases ; 
 this form of antennae is chiefly found in the division Lamel- 
 licornes of the order Coleoptera, or Beetles, of which the 
 Cockchafer is an example. Most of the antennae require but 
 little preparation ; to soak them in pure turpentine for two 
 or three days and then mount in balsam is all they require 
 if tolerably transparent. When thickened they must be 
 rendered transparent by the action of the diluted potassa. 
 
 Fig. 124. Leg, with stickers, of the Greater Heater-Beetle 
 (Dytiscus marginalis), x 8. 
 
 The remarkable expansion of part of the leg of this Water- 
 Beetle into a shield, or, as it is called, a patella, will be noticed 
 in the drawing. This peculiarity is only found in the male 
 insect. The tarsus, or foot, is covered with minute suckers 
 or disks, convex in their structure, and often seated on short 
 stalks; there are also generally to be found two or more 
 larger suckers or disks. 
 
 This object may be mounted in an opaque cell; or it may 
 be treated with potassa, washed, dried, and mounted in balsam 
 as usual. 
 
Fig. 125. 
 
 Fig. 126. 
 
 -.o H.MaAa. ad nat del 
 
 London. John. Van. Voorst. 
 
MICROSCOPIC OBJECTS. 63 
 
 Fig. 125. House-Cricket (Acheta domestica), natural size. 
 Order Orthoptera. 
 
 The order Orthoptera contains some of the most interesting 
 insects in regard to their structural characteristics. Among 
 the most remarkable may be mentioned the Mantis, Cock- 
 roaches, Earwigs, Locusts, Crickets, &c. The description of 
 the general structure of this order is as follows : " Wings 
 four, the upper coriaceous, veiny ; the inferior membranous, 
 longitudinally plaited like a fan j mouth serving for mandu- 
 cation, with strong mandibles; maxillse furnished with a 
 cylindrical helmet : metamorphosis incomplete." 
 
 The House-Cricket is one of the best insects for an amateur 
 to dissect, as the organs are tolerably large, and at the same 
 time interesting. Small specimens may be mounted in bal- 
 sam after the usual treatment for insects. 
 
 Fig. 126. Eye of Locust (Acrydium migratorium), x 80. 
 
 The eyes of insects vary much in size, and also in the 
 number of facets composing a single eye. Some of the 
 largest are to be found in the Libellulae (Dragonflies) ; but, 
 from the size of the facets, the eye of the Locust may be con- 
 sidered one of the first. Insects see differently from us, 
 as each of the facets answers to the single eye of a higher 
 animal ; therefore the objects are reflected to them in much 
 larger numbers, and no doubt this acute impression that their 
 brain receives causes that extreme quickness of sight for 
 which most insects are remarkable (see the various insect- 
 eyes). Many of the eyes are best mounted dry, after being 
 well washed, &c. ; others are best when mounted in fluid ; 
 and scarcely any show well in balsam, as it makes them too 
 transparent. 
 
Fig. 
 
 Fig. 
 
 /no.K.Mutrn. act naf del 
 
 loadon. Joon. Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 64 
 
 Fig. 127. Gizzard of House-Cricket (Acheta domestica), 
 
 x20. 
 
 The variety of gizzards and gastric teeth to be found in 
 insects, more especially in the orders Orthoptera and Coleo- 
 ptera, is to a certain extent unlimited ; a field is open here 
 for wide research, especially in foreign insects. The beauty 
 of these structures will always make them attractive objects 
 to microscopists. The dissection of a gizzard taken from the 
 House-Cricket will lead the way for further inquiry and re- 
 search. 
 
 The mode of preparation is to separate the gizzard from 
 the alimentary canal, cut it open with a fine pair of scissors, 
 boil it in a weak solution of potassa fusa until clean, wash in 
 warm water, and mount in a cell containing acetic acid. 
 
 Fig. 128. Noise-apparatus of House- Cricket (Acheta 
 domestica) , x 20. 
 
 The well-known song of the Cricket perhaps requires a 
 slight explanation. The upper coriaceous wings of this insect 
 possess near their inner margin a short, horny, and rasp-like 
 apparatus, one to each wing. By the rapid motion given to 
 the wings by the strong voluntary muscles, on the rasp- like 
 bodies touching each other they produce a sound not unlike 
 the chirping of some young birds ; the sound is also greatly 
 assisted by the membranous substance stretched over the 
 surface of the wings. The drawing represents the rasp-like 
 bodies in the act of producing the sound. The wings must 
 be well washed, dried under pressure, soaked in turpentine, 
 and mounted in balsam. 
 
Fig. 130. 
 
 &d nal del 
 
 London., John. Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 65 
 
 Fig. 129. Tongue of the House-Cricket (Acheta domestica), 
 
 x 15. 
 
 The tongues of the various insects differ according to the 
 work that they have to perform, as may be seen by examin- 
 ing the descriptions and figures of the various tongues. The 
 common House-Cricket, living chiefly on suction, has a tongue 
 that is well adapted to the purpose, being composed of a 
 quantity of minute tubes, which all join at last into two large 
 ones, which conduct the juices into the alimentary canal. 
 The Crickets are also furnished with strong mandibles. 
 
 The tongue may be dried under pressure, and mounted in 
 balsam ; or it may be mounted in a shallow cell with acetic 
 acid. The last mode of preparation shows the tubes of the 
 tongue best. 
 
 Fig. 130. Water- Scorpion (Nepa cirierea), natural size. 
 Order Hemiptera, Division Heteroptera. 
 
 The insects of this division of the order are chiefly remark- 
 able for having the elytra half membranous and half coria- 
 ceous. The beak also projects from the upper part of the 
 head (see drawing) ; and this beak is characteristic of the 
 order. 
 
 The insect is tolerably common in most ponds. The 
 appendage at the extremity of the insect is used for the inspi- 
 ration of air, and, no doubt, also as an ovipositor. The name 
 Water- Scorpion has been well applied; for its rapacity is very 
 great, as may be found by personal observation. 
 
 The insect, though very thick and coriaceous, may, by long 
 maceration in the potassa, be rendered sufficiently soft and 
 pliable to be pressed between two slips of glass, then well 
 washed, dried under pressure, soaked in turpentine, and 
 mounted in balsam as usual. 
 
Fig. 1S1. 
 
 Fig. 132,. 
 
 London,. JdraVaxi Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 66 
 
 Fig. 131. Hop- Aphis (Aphis humuli), x 20. Order Hemi- 
 ptera, Division Homoptera. 
 
 The insects of this division of the order Hemiptera are 
 chiefly distinguished by having their beak growing from the 
 lower part of the head also by not having the elytra half 
 coriaceous and half membranous as in the Heteroptera, but 
 all of membranous consistency. The Hop-Aphis is one of the 
 most troublesome insects to farmers ; and if it were not for the 
 larva of the Coccinella and other insects living entirely upon 
 them, they would be more so. The sweet fluid which these 
 insects secrete, called honey-dew, is much liked by ants ; this 
 fluid exudes from the two tube-like processes called " paps/' 
 situated at the back. On the ants pressing these "paps" 
 gently, they are able to procure this fluid, of which they are 
 extremely fond. These insects are best mounted in acetic 
 acid, in a shallow cell, sealed with liquid india-rubber or 
 dissolved gutta percha. 
 
 Fig. 132. Wing-case (Elytron) of Water-boatman (Notoiiecta 
 glauca), x 5. 
 
 The elytron of this insect has been taken to illustrate the 
 partially membranous and coriaceous elytra of the division 
 Heteroptera of the order Hemiptera, as mentioned at fig. 130. 
 On referring to the drawing, the membranous may be distin- 
 guished from the coriaceous or leathery parts, the membranous 
 being nearly transparent, and the coriaceous having a more 
 opaque appearance. 
 
 This, together with most of the transparent elytra of the 
 various insects, requires scarcely any preparation, simply 
 soaking in hot water, and drying under strong pressure, then 
 placing it in turpentine for a few minutes, and mounting in 
 balsam. 
 
iq. IBS. 
 
 Jno H.]<i"nrtiii. 
 
 London, Jofcn.VaiL Vborsr. WDCCCIXX. 
 
MICROSCOPIC OBJECTS. 67 
 
 Fig. 133. Rostrum and Lancets of the Bug (Cimex lectu- 
 larius) , x 40. , 
 
 This is another example of the beak for which the order 
 is noted; only, in this case, it is furnished with lancets. 
 These lancets are about -^ less than the lancets of the Flea (see 
 fig. 162). These insects seem to draw the blood, not by suc- 
 tion, as the Leech, but by moving the three thread-like setae 
 or lancets against each other ; this causes the blood to flow 
 up the rostrum or beak with a kind of capillary motion. The 
 eggs of this Bug make a good object where mounted opaque, 
 
 To mount the insect it must be soaked in diluted potassa 
 fusa for at least twelve hours, then press out the contents of 
 the body, place it in the potassa for two hours more, well 
 wash in warm water, dry under strong pressure, soak in tur- 
 pentine, and mount in balsam. 
 
 Fig. 134. Saws of Froghopper (Cercopis spurn aria), x 40. 
 
 Of all our common British insects, perhaps this is one of 
 the least-known. Most persons have seen the frothy appear- 
 ance on branches and leaves in the early summer months, 
 and also know that it is commonly called Cuckoo-spit ; and 
 that is nearly all they know about it. Few persons have 
 examined this little insect with its various natural apparatus 
 for the several functions it has to perform, and without which 
 the species would soon be extinct. The mature insect is fur- 
 nished with extremely fine saws (see drawing), with which it 
 cuts a slit in generally the last annual shoot, and deposits an 
 egg. The larva, on leaving the egg, immediately covers itself 
 with a froth, in this way : fixing its beak (which organ is cha- 
 racteristic of the order) into the cellular tissue of the'plant on 
 which it is situated, it sucks up sufficient of the sap to cover 
 itself, and then pours out a secretion from the organs placed 
 at the end of its body ; this secretion is the froth. The insect 
 is thus protected, and passes through its stages, until it arrives 
 at the perfect state. The larva may be mounted in acetic 
 acid, or dried and in balsam. The mature insect is best 
 mounted in balsam. 
 
 K2 
 
Fig. 135. 
 
 Fig.. 136. 
 
 H Malta. &i not dd.. 
 
 John. "Van. "Voorst. WDCCCLXX. 
 
MICROSCOPIC OBJECTS. 68 
 
 Fig. 135. Larva of the Ant-lion (Myrmeleon formicarius) , 
 x 4. Order Neuroptera. 
 
 The chief characteristics of the order are: that the perfect 
 insects have four large membranous wings, of which the 
 Dragonfly is an example ; and that the larvae are nearly all 
 furnished with very strong mandibles, in the case of some of 
 the Dragonflies called the mask (see fig. 136). Most of the 
 larvae of this order live in water ; but the larva of the Ant-lion, 
 with others, forms an exception. With its strong legs and 
 mandibles it makes for itself a funnel of loose sand or soil, 
 at the bottom of which it lies concealed, waiting for its prey. 
 This larva is also furnished with very strong mandibles. 
 
 It is best mounted in balsam. The perfect insect very 
 much resembles the small blue Dragonfly (Agrion puella) 
 that is so very commonly met with at the margins of our 
 rivers and ponds. 
 
 Fig. 136. Head of Larva of the Long-bodied Dragonfly 
 (Agrion virgo), x 12. 
 
 The larvse of the Dragonflies are furnished with a kind of 
 moveable mask, which is armed with very strong pincers. 
 This mask is concealed under the head of the insect, and 
 when called into action it is darted forward to nearly the 
 entire length of the body. After its prey has been caught, 
 it is brought by this peculiar apparatus into the reach of the 
 mouth. The respiration of the larvae of the Dragonflies is 
 also remarkable ; they take in a certain amount of water, 
 and, after the oxygen has been exhausted, discharge the same 
 suddenly (by this mechanism the larva is also propelled in 
 the water) . 
 
 The larvae may be mounted in a cell in strong acetic acid, 
 or dried and mounted in balsam. 
 
Fig. 187- 
 
 Fig. 158. 
 
 ad -n&i del 
 
 London, Jclm. Van Voorst. MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 69 
 
 Fig. 137. Eye of Dragonfly (Libellula depressa), x 200. 
 
 The eye of the Dragonfly is well adapted for the work 
 which it has to perform, which is to perceive quickly any 
 insect in its rapid flight through the air. On examining a 
 Dragonfly the eyes will be found to comprise nearly all the 
 head ; they are also extremely prominent. The structure of 
 the eye is the same as in other insects (see fig. 126 &c.) ; but 
 the lenses are rather larger than those of the Diptera, Lepido- 
 ptera, &c. 
 
 After separating the eye, it must be macerated for a short 
 time in the diluted potassa, well washed, and dried under 
 pressure ; it may then be mounted dry, or in a shallow cell 
 with acetic acid, or any other good preservative fluid. 
 
 Fig. 138. Meadow- blue Butterfly (Polyommatus Alexis), 
 natural size. Order Lepidoptera. 
 
 This Butterfly has been taken to illustrate the order. The 
 chief difference between the Moths and the Butterflies lies in 
 the antennae of the former terminating in a point, those of 
 the latter in a clavate or club-shaped end. The position of 
 the scales on the wing-membrane is nearly the same in both 
 divisions of the order (see fig. 142). Both Moths and Butter- 
 flies furnish a large series of instructive objects. One of the 
 most characteristic structures of the order is the proboscis 
 (see fig. 141). Many of the eggs are also most beautiful 
 objects (see figs. 143, 144). The scales as situated in situ 
 on the wings are generally best when mounted in a dry opaque 
 cell. 
 
Fig, 139. 
 
 Fig. 140. 
 
 ad nat.del 
 
 London. John. "Van "Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 139. Spiracle of Larva of the Death? s-Head Hawk- 
 Moth ( Acherontia atropos) , x 20. 
 
 The spiracle of the larva of this moth (which is generally 
 found on the potato-plant) may be taken as the general type 
 of the spiracles of most of the larvae of the Moths and Butter- 
 flies. On dissecting any larva, a number of minute tubes, 
 greatly resembling the spiral vascular tissue of plants (see 
 fig. 16), will be found leading to each spiracle or breathing- 
 pore; these tubes or tracheae are figured in the following 
 drawing. 
 
 The spiracles, when cut away from the side of any larva, 
 must be soaked for a short time in diluted potassa fusa as 
 usual, then well washed, dried under pressure, soaked in tur- 
 pentine, and mounted in balsam ; or they may be mounted 
 in a shallow cell in acetic acid. 
 
 Fig. 140. Tracheae of Silkworm (the larva o/Bombyx mori), 
 
 x40. 
 
 Tracheae of all insects resemble each other in structure, 
 although differing greatly in size. They are best seen when 
 taken from any of the larvae of the large Moths or Butterflies. 
 They consist of tubes greatly resembling the spiral vascular 
 tissue of plants (see fig. 1 6), and, like the components of this 
 tissue, they may be uncoiled. These tubes lead to the air- 
 pores, or, as they are called, the spiracles (see figs. 122, 139, 
 154, &c.) of insects, and serve to conduct the air to all the 
 central parts of the body. 
 
 The tracheae show best when mounted in fluid, although 
 they may be dried and mounted in balsam. 
 
Fig. 
 
 Fig. 
 
 TnuE Malta, ad a&rdel 
 
 London, John. "Van. Voorst. MDCCCIXX 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 141. Proboscis of Humming -Bird Hawk-Moth (Macro- 
 glossa stellatarum) , x 20. 
 
 The antlia, or, as it is commonly called, the proboscis, of 
 the Lepidoptera is an organ most beautifully adapted for its 
 purpose, which is to convey the honey of flowers to the mouth 
 of the insect. It is composed of two maxillse containing a 
 great number of strong muscular bands. These maxillse 
 when separate are convex on the outer and concave on the 
 inner side ; so when they are joined together they form a tube 
 (see drawing) ; inside this tube are often found a number of 
 tracheae communicating with the head, and in some species 
 the tip of the proboscis is furnished with a number of papillse. 
 
 The antlia may be mounted in a cell with strong acetic 
 acid ; or placed in diluted potassa fusa for two hours, well 
 washed, dried under pressure, and mounted in balsam. 
 
 Fig. 142. Scales of the Six-spot Burnet-Moth, in situ 
 (Zygsena filipendulse) , x 100. 
 
 All Moths and Butterflies, and a few other insects, are fur- 
 nished with a large number of minute epidermal bodies called 
 scales ; and it is these scales that give the gorgeous colouring 
 to the wings of the various species. The scales vary much 
 in size, shape, and colour ; they are inserted into the mem- 
 brane of the wing by the short stalks which fit into the cups 
 or holes placed in the membrane (see drawing) . These flat 
 scales are generally ranged in rows, and overtop each other 
 in the same way as the scales of a fish. 
 
 To show the scales well, it is best to mount the wing in an 
 opaque cell ; or if wanted to show their attachments in situ, 
 the wing must be rubbed and then mounted in a dry trans- 
 parent cell, which is best made of cardboard. 
 
Fig. 143. 
 
 Fig. 144. 
 
 London.. 
 
 MDCCCLXX 
 
MICROSCOPIC OBJECTS. 72 
 
 Fig. 143. Eggs of small Copper Butterfly (Chrysophanus 
 Phheas), x30. 
 
 The eggs of many insects,, more especially those belonging 
 to the order Lepidoptera, greatly resemble many of the 
 smaller seeds in their superficial microscopic appearance (see 
 fig. 45) . Most of them are very distinctive in their markings, 
 and the exact species may almost always be ascertained from 
 their examination. But there is still a large field for micro- 
 scopic investigations, as the eggs of many insects have never 
 been examined at all. 
 
 They are rather difficult to mount well. The simplest plan 
 is to wait until the small caterpillar emerges from the eggs ; 
 or their vitality may be destroyed by the application of a red- 
 hot needle, but care must be taken to only just prick the 
 egg ; they may then be mounted in a dry opaque cell. 
 
 Fig. 144. Eggs of Willow- beauty Moth (Boarmia 
 rhomboidaria), x40. 
 
 The Moth from which these eggs were taken, is found 
 nearly everywhere, but more especially on plum and birch 
 trees. The eggs of many of the Moths are quite as beautiful 
 as the eggs of the Butterflies ; but scarcely any of them have 
 ever been mounted, drawn, or described. 
 
 These eggs may be mounted in the same manner as those 
 previously described. 
 
Fig. 145. 
 
 Fig. 146. 
 
 Jn.aH.MaitJn. &d n&t.del 
 
 London., John Van. Voorst. MDCCCLXX. 
 
 Im-p. 
 
MICROSCOPIC OBJECTS. 73 
 
 Fig. 145. The Common Wasp (Vespa vulgaris), natural size. 
 Order Hymenoptera. 
 
 The order Hymenoptera includes most of the architectural 
 (or nest-building) insects, which are also noted for their great 
 intelligence. The chief structural characteristics of the order 
 are : " Wings four, when at rest lying horizontally upon the 
 body, membranous; posterior ones smaller, and with fewer 
 veins, and generally having a single row of hooks; maxillae 
 elongate, generally slender, sheathing the labium ; mandibles 
 two ; abdomen of the females almost always terminated by a 
 borer or a sting : metamorphosis complete." On referring 
 to fig. 147, the row of hooks mentioned in this description 
 will be seen in their natural position, as placed when the 
 wings are united. Bees, Wasps, Ants, Grail-insects, Sawflies, 
 Ichneumons, &c. all belong to this order. 
 
 Wasps &c. may be mounted whole after prolonged mace- 
 ration in tolerably strong solution of potassa fusa, well wash- 
 ing, drying under strong pressure, and then mounting in 
 balsam. 
 
 Fig. 146. Tongue of Sand- Bee (Andrsena melitta), x 20. 
 
 This tongue has been taken to illustrate the general struc- 
 ture of the tongues of the Bees and Wasps. It is as well 
 adapted for suction as the proboscis or tongue of the Blow-Fly 
 (see fig. 151), though of a different form ; and it is also sup- 
 posed to be the chief instrument which the Bee uses in the 
 manufacture of her marvellous hexagonal cells. The Bee 
 having sucked up sufficient honey from the flowers with this 
 organ, returns the same to the mouth, whence the honey is 
 conveyed into the first stomach; part of it passes into the 
 abdomen, and is manufactured into wax; the rest, on the 
 arrival of the Bee at the hive, is deposited in a cell. The 
 appendages of this organ, viz. the maxillae and the labial palpi, 
 also greatly assist the tongue in performing these marvellous 
 duties. 
 
 The ligula, or tongue, on being separated from the insect, 
 must be soaked for a short time in diluted potassa fusa, well 
 washed, dried under strong pressure, placed in turpentine 
 until transparent, and mounted in balsam. 
 
Fig. 147- 
 
 Fig. 148. 
 
 Jno.H-Maabn. ad nat del 
 
 Londoa John. Tan Voorst . MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 74 
 
 Fig. 147. Parts of the Wings of the Common Wasp, showing 
 the natural position of the Hooks ( Vespa vulgaris) , x 100. 
 
 The drawing represents the single row of hooks,, when seen 
 in their natural position that is, when the posterior or 
 smaller wing is hooked on to the larger, so as to appear to a 
 superficial observer as one wing (see the natural insect, also 
 the drawing of the same). This peculiarity is one of the 
 structural characteristics of the order. 
 
 The wings are easily mounted, the best plan being to well 
 wash them in warm water, place in their natural positions, 
 dry under strong pressure between two slips of glass, soak in 
 turpentine until transparent, and mount in balsam. 
 
 Fig. 148. Leg of the Neuter or Working Hive-Bee (Apis 
 mellifica), x 10. 
 
 Another fine structural organ or, rather, instrument of this 
 order is the leg (see drawing). On noticing this, it will be 
 seen that the first joint of the tarsus, or foot, is closely 
 covered with a multitude of small stiff hairs; these form a 
 kind of brush, with which the Bee brushes the pollen-dust 
 from the anthers and stamens of flowers (see fig. 44) into the 
 cavity made to receive the same. This basket, or cavity, is 
 placed outside the brush, or first joint of the tarsus, and the 
 joint of the leg called the tibia ; the hinge which connects 
 these two joints is marvellously strong, and also very flexible. 
 It is a well-known fact that Bees never gather the pollen, but 
 from one species, or at the most, from allied species of plants 
 at each journey. The reason of this is, that pollens differ 
 greatly in size (see figs. 40, 41, &c.), and by the laws of 
 cohesion, particles of matter of various sizes cohere with 
 much more difficulty than particles all of one size ; the Bee, 
 therefore, only gathers the pollen of one kind of plant on 
 each separate journey. With this pollen the Bee makes her 
 Bee-bread, with which to feed the larvae. 
 
 The leg may be mounted as a transparent or opaque object ; 
 the mode of treatment is as usual. 
 
Fig. 149. 
 
 Fig. 150. 
 
 Jiio.H.Majtm. ad uat.dd. 
 
 Join. "Via "Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 75 
 
 Fig. 149. Sting of Hive- Bee (Apis mellifica), x 20. 
 
 The sting may be considered as a modified form of ovi- 
 positor (see figs. 125, 130). It consists of a sheath, divided 
 on the underside through its entire length; from this slit 
 the setae, or lancets, are protruded at will ; these lancets are 
 furnished at the extremity with fine teeth ; the entire appa- 
 ratus is supplied with very strong muscles, and both the 
 sheath and the setae can be withdrawn or protruded from the 
 abdomen at pleasure. At the base of the sheath are two 
 poison- glands, which poison, by the action of the setae, is 
 deposited in the wound made by them. The chief use of the 
 sheath appears to be to protect the fine points of the setae, or 
 lancets, from injury. 
 
 After separating the sting from the insect, it must be sof- 
 tened by placing it in the diluted potassa fusa for a few hours, 
 after which it must be well washed, and the lancets drawn 
 out from the sheath with the point of a fine needle; they 
 must then be placed in a natural position, dried under pres- 
 sure, and mounted in balsam. 
 
 Fig. 150. A Small Fly (Thrips physapus), x 20. 
 Order Thysanoptera. 
 
 This extremely small Fly, being only about -^ inch in 
 length, has been taken to illustrate the order. The chief 
 structural peculiarities are : "Wings four, alike, long, narrow, 
 membranous, neither folded nor reticulated, with long cilia ; 
 mouth with two setiform mandibles, two triangular palpige- 
 rous maxillae, and a palpigerous labium ; tarsi 2-jointed, 
 vesicular at tip." The Thrips may generally be found in the 
 flowers of the small Bindweed or Convolvulus (Convolvulus 
 arvensis] ; and in sultry summer weather scarcely a Convol- 
 vulus can be found without them. 
 
 Most flies are not at all difficult to mount ; they must be 
 macerated in the liquid potassa, according to size, from three 
 or four hours to three or four days, then pressed gently be- 
 tween slips of glass, so as to force out the contents of the 
 abdomen &c., then replace the insect in the potassa for a 
 short time, well wash in warm water, dry under pressure, 
 soak in turpentine until transparent, and mount in balsam as 
 usual. 
 
151. 
 
 Fia. 
 
 Jhc-EMaito.. ad.natdeL 
 
 London... John. "Van "Voorst . MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 76 
 
 Fig. 151. Tongue of Blow -Fly (Musca vomitoria), x 20. 
 
 One of the most marvellously constructed instruments 
 with which insects are furnished is the proboscis, or tongue, 
 of the Blow-Fly, to thoroughly describe which would take 
 many pages. The broad part at the top of the drawing 
 represents the two lobes of the ligula; these lobes contain 
 a number of minute tubes, kept partially open by rings ; and 
 through these fine channels the fluid sugar is thoroughly 
 filtered before it enters the mouth. A duct, which serves to 
 convey a fluid with which to soften sugar and other sub- 
 stances, also runs into the tongue. Both of these necessary 
 parts are kept in action by the muscularity of the pharynx, 
 which part is at the bottom of the drawing. The contraction 
 of this sends the salivary fluid to the food to moisten it, and 
 the dilatation of the same forms a suctorial power, with which 
 the liquid food is conveyed into the mouth. 
 
 The proboscis must be dilated by pressing the thorax of the 
 Fly, then cut off with a fine pair of scissors (the Fly having 
 been previously killed in alcohol), next placed gently in its 
 natural position, squeezed flat, dried under pressure, soaked 
 in turpentine until transparent, and mounted in balsam ; or 
 it may be mounted, without preparation, in glycerine. 
 
 Fig. 152. Lancets of the Female Mosquito (Culex mosquito), 
 
 xlO. 
 
 Another form of tongue is found in the Gnats, of which 
 this drawing may be taken as a type. It consists of a labrum 
 or tongue, which is the largest part (see drawing) ; another 
 part, slightly smaller, called the labium, forms a kind of 
 sheath for the mandibles and maxillae, which in this case 
 are generally called the setae or lancets; they are four in 
 number ; three of them have been separated from the labium, 
 or sheath, so as to show their structure, two of them being 
 furnished with fine teeth, while the other two terminate in a 
 fine sharp point. In addition to the irritation caused by the 
 action of these setse, a drop of poison is instilled by them into 
 the wound, so as to render the blood more liquid for the 
 suctorial action of the labium. The other parts represented 
 in the drawing are the long pilose antennae, and the two short 
 and thick bodies called the maxillary palpi; the eyes are also 
 shown. 
 
 These objects simply require to be placed in their natural 
 position, dried under strong pressure, and mounted in balsam 
 as usual. 
 
Figi, 153. 
 
 Fig. 154. 
 
 ad.nat.del 
 
 London- Job. Van. Soarst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 77 
 
 Fig. 153. Spiracle of Blow -Fly (Musca vomitoria), x 40. 
 
 Other forms of spiracles are drawn in figs. 122, 139, &c. ; 
 the form is generally oval. To prepare this spiracle for 
 mounting, the thorax of the Fly must first be macerated in a 
 strong solution of potassa for two days, then cut open and 
 well washed. A spiracle may then be cut away, and mounted 
 separately ; or the entire thorax with its four spiracles may be 
 dried under pressure between two glass slips, soaked in tur- 
 pentine until transparent, and mounted in balsam. 
 
 Fig. 154. Spiracle of the Breeze-Fly of the Horse ((Estrus 
 equi) , x 20. 
 
 Another peculiar form of spiracle is drawn here ; it rather 
 represents a number of small spiracles massed into one. In 
 the centre of each ring which passes round the worm-like 
 bodies will be seen a small hole ; through these fine holes the 
 air passes into the tracheae ; and by the contraction of these 
 worm-like bodies no doubt the holes are closed at will. The 
 Breeze-Fly of the sheep ((Estrus ovis) has quite a differently 
 shaped spiracle, although the characteristics of the structure 
 are the same, viz. a number of minute holes closed at will by 
 an elastic or flexible tissue. 
 
 The method of preparing this spiracle is the same as that 
 given in the description of the preceding figure. 
 
"Fig. 155. 
 
 Fig. 156. 
 
 Jho-H-MaatJa.. ad nat.del . 
 
 londoa. John Van Voorst. MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 78 
 
 Fig. 155. Foot of a Fly (Scatophaga stercoraria), x80. 
 
 At the extreme end of the tarsus, or foot, in most flies, is 
 found a small pad or cushion called the pulvillus. It is 
 generally placed between two claws, or hooks (see drawing), 
 and is supposed to enable the Fly, by its suctional action, to 
 walk on smooth surfaces. The pulvillus is often covered with 
 a number of disk- like hairs, and is also occasionally accom- 
 panied by a strong hair-like appendage. This must also 
 greatly assist the Fly in walking over any smooth surface, as 
 it would take advantage of any irregularity upon it. After 
 the pad has been placed in its naturally extended position, it 
 must be dried under very strong pressure, and mounted in 
 balsam as usual. 
 
 Fig. 156. Eye of the Common House-Fly (Musca domestica), 
 
 x200. 
 
 These facets are much smaller than those figured in fig. 
 137. The eyes of insects, as mentioned in the description of 
 fig. 126, consist of a number of simple eyes, or facets, joined 
 together at their angles, so as to form an oval convex surface 
 protruding from the head, one on each side. In each single 
 eye of the House- Fly there are about 4000 facets ; and some 
 insects, such as the Dragonflies &c., have even more than 
 this. 
 
 After having macerated the eye in liquid potassa for about 
 six hours, so as to clean it from blood &c., it must be well 
 washed, a slit cut in it, then dried between writing-paper 
 without much pressure, and mounted in a shallow dry trans- 
 parent cell made of cardboard; or the entire eye may be 
 mounted in a dry opaque cell without any previous prepara- 
 tion. 
 
157. 
 
 Fig. 158, 
 
 ad nat del 
 
 London, John. Van. Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 79 
 
 Fig. 157. Larva of the Bot-Fly as seen in the Egg (CEstrus 
 bovis), x40. 
 
 This Fly is extremely hairy : the head is covered with light 
 yellow hairs ; the thorax is also yellow and barred with black, 
 the abdomen being partly black, but terminating in an orange- 
 yellow colour. The Fly is much dreaded by cattle when in 
 the open pastures. The insect generally lays its eggs under 
 the surface of the skin, with an ovipositor adapted to the pur- 
 pose ; but occasionally they may be found on the hairs of the 
 animal (see drawing) . After the larva is matured by living 
 on the flesh of the ox, it falls to the ground, and works under 
 a stone or buries itself; it then passes into the cocoon-state, 
 and in course of time emerges as a perfect Fly. The spiracle 
 of a Fly closely allied to this insect is drawn in fig. 154. 
 
 The eggs, when found, may be soaked in turpentine, and 
 mounted with Canada balsam, in a cell so as to take off all 
 undue pressure. 
 
 Fig. 158. Eggs of a Species of House-Fly (Anthomyia cani- 
 cularis) , x 40. 
 
 The Flies of the genus Anthomyia closely resemble the 
 common House-Fly (Musca domestica], both in appearance 
 and habits; but unlike the House-Fly they do not quite restrict 
 themselves to habitations, being often found on plants of the 
 field. The eggs of this species are of great beauty ; they are 
 generally deposited in the ground. 
 
 The eggs are best seen when mounted in a dry opaque cell. 
 
Fig. 160 
 
 ad nat del. 
 
 Londpn John. Vsm. Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 80 
 
 Fig. 159. Pigeon's Flea, female (Pulex columbse), x 15. 
 Order Aphaniptera. 
 
 The different species of Fleas are chiefly distinguished from 
 each other by the different lengths of the joints of the leg and 
 tarsus. The following is the description of the order : 
 1 ' Wingless ; metamorphosis complete ; mouth suctorial ; ros- 
 trum composed of two serrated laminae and a thin suctorial 
 seta (see fig. 162), included in a jointed two-valved sheath." 
 The description of the species shown in the drawing is as 
 follows : " Prothorax with a pectinate fringe, none upon the 
 abdomen ; antennae of male erect, those of the female lying 
 in the depression." The abdomen of the female Flea generally 
 has nine segments. 
 
 Most Fleas require to be macerated in the potassa for two 
 or three days, then to be pressed between glass slips so as to 
 remove part of the internal matter, replace them in the potassa 
 for a short time, when the rest of the contents will soon come 
 out under pressure ; dry, soak in turpentine until transparent 
 and mount in balsam as usual. 
 
 Fig. 160. Mouse's Flea, male (Pulex muris), x 40. 
 
 The general outline of the male Fleas seems quite different 
 from that of the females. Instead of the abdomen being in 
 a line with the head and thorax, it is turned up as if the 
 insect had been bent. The male insect has also erect 
 antennae (see drawing), and in the posterior legs the first 
 joint of the leg, called the coxa, is rather larger than is com- 
 monly found in other species ; and in the anterior and middle 
 legs the last joint of the tarsus is also large. 
 
 The method of mounting is the same as in the preceding 
 description, only that the species, being much smaller, requires 
 less time in the potassa. 
 
Fig. 161. 
 
 Fig. 
 
 Mmn.. ai nat del 
 
 Ion don. Jolm.'Var.Vc.-jrst MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 81 
 
 Fig. 161. A Human Flea, female (Pulex irritans), x 15. 
 
 The human Flea has been drawn chiefly to show its simi- 
 larity to the other species of Flea ; but upon considering the 
 description of the species, which is as follows, it will be found 
 that the structural characters are slightly different : Pitch- 
 brown ; head shining, smooth, pectinate fringe absent ; legs 
 pale ; femora of the posterior legs with hairs inside ; fifth 
 joints of the tarsi of the anterior pair of legs the largest, and 
 the first joints of the posterior tarsi the longest. The larvae 
 of this and other Fleas form interesting objects. 
 
 This species may be mounted in the same manner as the 
 preceding. 
 
 Fig. 162. Lancets of Human Flea (Pulex irritans), x 100. 
 
 Causing so much irritation, as these fine instruments do, 
 when forced into our skin, we cannot but admire, after a 
 microscopic view of them, their fineness of form and struc- 
 ture. The lancets, or mandibles, are on the right-hand side 
 of the drawing, and may be distinguished by their serrated 
 edges. Between them is the labrum, or the suctorial organ ; 
 the two antennae -like bodies with four joints, at each side of 
 the drawing, are the maxillary palpi ; the shield-like bodies 
 represent the maxillae, and the 4-jointed labial palpi placed 
 between these are the organs in which the lancets are 
 sheathed when at rest. 
 
 The lancets, with the surrounding parts, require very care- 
 ful mounting. The best plan, after they are cut off from the 
 head of the Flea, is to place them in the centre of a glass 
 slide, in a drop of balsam about the size of a pin's head, then 
 with a fine needle to place them in their proper positions, 
 after which, let the drop dry under a glass shade, so as to 
 keep off the dust. When quite dry, place the thin cover on, 
 and let diluted Canada balsam run in by capillary attraction, 
 so as not to disturb the objects; finish as usual. 
 
 M 
 
Fig. 163. 
 
 *d uat fci 
 
 Loadon,. John. "Van. Voorst. MDCCCLXX 
 
MICROSCOPIC OBJECTS. 82 
 
 Fig. 163. A Human Louse (Pediculus vestimenti) . 
 Order Anoplura, x 16. 
 
 The description of this repulsive insect, which has been 
 taken as a type of the order and genus, is as follows: 
 Colour dirty white ; elongate- ovate ; thorax large, not con- 
 stricted from the abdomen ; head much produced ; antennae 
 5 -jointed; mouth with a fleshy rostrum concealed beneath 
 the head, consisting of a soft tubular sheath dilated at the 
 end, where it is furnished with a double row of hooks, and 
 containing a horny tube formed of four setse; abdomen with 
 seven segments indistinctly indicated ; legs all scansorial or 
 prehensile ; length about ^ inch. 
 
 The insect may be mounted in balsam as usual. 
 
 Fig. 164. Parasite of Horse (Trichodectes equi), x 20. 
 
 Other insects of the same order as the preceding are para- 
 sitic upon some quadrupeds, viz. the Horse, Sheep, Ox, Dog, 
 &c., in all about ten species. The characteristics of the 
 genus are : Head subquadrate, with two black spots in 
 front, and a black band on each side ; antennae filiform, 
 3-jointed ; maxillary palpi none, or inconspicuous ; mandibles 
 2-toothed; tarsi 2-jointed, with one claw; abdomen oval. 
 
 The insect usually only requires to be dried between writing 
 or glazed paper, under moderate pressure, soaked in turpen- 
 tine until transparent, and then mounted in balsam. 
 
Fig. 165. 
 
 Fig. 166. 
 
 aAnsr del 
 
 Lc-idoa KbB.VtD.Vbaa* MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 83 
 
 Fig. 165. Parasite of Starling (Philopterus leontodon), 
 
 x20. 
 
 The insects of this genus are parasitic upon birds; the 
 species are numerous. The characteristics of the genus 
 are : Antennae filiform, 5 -jointed ; maxillary palpi none ; 
 mouth with strong toothed mandibles ; tarsi with two claws ; 
 head generally triangular. Most of the species are of a 
 chestnut-colour. 
 
 They may be mounted in the same way as described in the 
 case of the preceding species. 
 
 Fig. 166. Eggs of Parasite of the Crowned Hornbill 
 (Buceros coronatus), x 25. 
 
 Many of the eggs of the insects belonging to the order 
 Anoplura are most beautiful in form and structure, and pos- 
 sess also the great advantage of not having been at present 
 much studied. No doubt, if the hairs of animals and the 
 feathers of birds were well examined, microscopists would 
 find abundance of beautiful forms at present unknown, or 
 nearly so. The eggs of many other orders of insects will also 
 be found most interesting (see figs. 143, 144, 158, &c.). 
 
 The eggs generally show best when mounted in a dry 
 opaque cell. 
 
 M 2 
 
Fig. I6/. 
 
 ig 168. 
 
 7rLO.K.MaiOa. ad nar ]&L 
 
 Louder. JeLnVaiL Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 84 
 
 Fig. 167. House-Spider (Aranea domestica), x 3. 
 Class Arachnida. 
 
 The Class Arachnida, which comprises the Spiders, Mites, 
 &c., does not belong to the Class Insecta proper, but is placed 
 between them and the higher articulated animals. The de- 
 scription of the order is as follows : Head united with the 
 thorax, forming a cephalothorax ; antennae none ; eyes simple 
 (ocelli) ; legs eight, jointed. The organs of the mouth vary 
 according to the families; in the Araneida, or the true Spiders, 
 they chiefly consist of mandibles (see fig. 168), and in the 
 Mites they often terminate in a bifid labium. Spiders may 
 be mounted in the same manner as any whole insect, viz. 
 with a fine needle prick a small hole in the abdomen, then 
 immerse in liquid potassa fusa for a few hours or days accord- 
 ing to size, next press gently between glass, replace in the 
 potassa for an hour or so, then press the rest of the matter 
 from the body. Well wash in warm water, dry under pres- 
 sure, soak in turpentine, or distilled Canada balsam, until 
 transparent ; finally mount in balsam as usual. 
 
 Fig. 168. Mandibles of the House-Spider (Aranea 
 domestica) , x 20. 
 
 The mandibles as mentioned at fig. 167, comprise the chief 
 part of the mouth of a Spider ; they are the two claw-shaped 
 bodies in the centre of the drawing ; each claw is pierced nearly 
 through so as to admit of a poisonous secretion passing from 
 the gland situated at its base up the canal and through the 
 small hole near its apex into the body of the insect attacked, 
 by a similar action to that of the sting of the nettle (see 
 fig. 35). On each side of these mandibles are situated the 
 maxillary palpi, and at their base are the maxillae; lastly 
 between these is the labium. 
 
 The method of preparation is the same as mentioned for 
 parts of insects (see figs. 141, 155, &c.). 
 
169. 
 
 . 170. 
 
 London. Jehu. "Van Voorst MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 85 
 
 Fig. 169. Foot of the Garden-Spider (Epeira diadema), 
 
 x60. 
 
 The leg of a Spider, as will be seen on referring to the 
 drawing, is admirably adapted for its work; the last joint of the 
 tarsus being generally furnished with three saw-like claws, by 
 means of which the Spider is enabled to retain its hold upon 
 the web and to pass down any part of the same with great 
 rapidity. 
 
 The leg simply requires to be well washed with a camel's- 
 hair brush, dried under pressure, soaked in turpentine, and 
 mounted in balsam. 
 
 Fig. 170. Spinnerets of the Garden-Spider (Epeira 
 diadema) , x 20. 
 
 At the base of the abdomen are situated three pairs of 
 conical-shaped bodies, these are the spinnerets ; and on re- 
 ferring to the drawing a number of minute tubes will be seen 
 on the summit of each. From these tubes the viscid matter 
 is drawn in single filaments, and it collects into one extremely 
 fine thread, with which the Spider manufactures it web. The 
 number of these spinning-tubes varies from about 1000 to 
 100 according to the age of the insect &c. The bases of the 
 spinnerets are closely covered with hairs to protect the tubes 
 from injury. The glands which secrete the viscid matter of 
 which the web is composed occupy the interstices of the other 
 viscera of the abdomen. 
 
 The part containing the spinnerets simply requires to be 
 placed in liquid potassa for two or three hours, well washed, 
 dried under pressure, and mounted in balsam. 
 
Fig. 171. 
 
 Fig. 17 . 
 
 *J tut. del 
 
 London. Jobs. "Van Voreat . MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 86 
 
 Fig. 171. Cheese-Mite (Acarus domesticus) , x 100. 
 Order Acarind. 
 
 A large division of the Class Arachnida is comprised in the 
 Order Acarina, or Mites, of which this drawing may be taken 
 as one of the types. This well-known animal belongs to the 
 same family as the Itch-parasite (see fig. 175), the most evi- 
 dent difference in their structure being the length and posi- 
 tion of the legs ; the description of the family (Acarea) is as 
 follows: Head terminated in front by an emarginate labium 
 or single bifid process ; palpi adnate, or adherent to the labium, 
 difficultly distinguished; mandibles chelate; no distinct 
 ocelli; legs generally terminated by a vesicle or adherent 
 acetabulum and claws. The eggs are very numerous. The 
 best method to examine the characters of the parts of the 
 mouth, legs, &c., is simply to crush the Mite between thin 
 glass, and wash with a solution of potassa ; but to permanently 
 preserve them great care must be taken in crushing them. 
 After being well cleaned from the potassa, they may be dried 
 and mounted in balsam ; or they may be mounted in glycerine 
 without any previous preparation. 
 
 Fig. 172. Parasite found on a Mason-bee (Trichodactylus 
 osmise), x 20. 
 
 This Mite belongs to the same family as the Cheese-mite, 
 but to a different genus. The description is as follows : 
 Rostrum or beak short, with minute bristles ; fourth pair of 
 legs longer than the rest, without claws, and terminated by a 
 long bristle ; the rest with two claws ; legs pale red. Found 
 upon a species of Mason-bee. 
 
 It may be mounted in the same manner as the preceding 
 species. Many of the Acari show well after being stained 
 with any of Judson's dyes, and then mounted in glycerine. 
 
Fig. 17 S. 
 
 74. 
 
 JKc/EMwha. ad -im dd 
 
 London.. Jbtn. "Van Voorst. MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 87 
 
 Fig. 173. Skin-Parasite from Human nose (Demodex 
 folliculorum), x 200. 
 
 The exact position, as regards the classification of this 
 parasite, is rather doubtful ; at present it is classed under the 
 family Acarea. On the nose and the parts adjacent, it is 
 generally to be seen in large numbers ; its presence is always 
 denoted by a minute black spot. The characters of the genus 
 are : Legs terminated by four or five claws ; no acetabula ; 
 abdomen annulose. 
 
 On the skin that contains these parasites being pressed, 
 from each black spot proceeds a small quantity of mattery 
 substance ; this contains the parasite, and also often a number 
 of ova. The mass may be placed at once in the carmine-dye, 
 and then transferred to a drop of glycerine ; next place it on 
 a glass slide, cover with thin glass, and then gently press the 
 dyed matter, after which, if a |-inch power is used, the para- 
 site will be distinguished from the surrounding mass. 
 
 Fig. 174. Eggs of Earth-mite (Tetranychus lapidum), x40. 
 
 The beautiful eggs of this mite may often be found on the 
 inside of the rough pieces of bark that are commonly seen 
 on old Elder trees &c ; they are also found on stones. The 
 description of the species is : Legs slender, anterior very 
 long ; eyes three on each side ; several rows of white spots 
 upon the back and margins of the body. 
 
 The eggs show best when mounted in a dry opaque cell. 
 
Fig. 175. 
 
 Fig. 176. 
 
 Jio.H.Martm.. ad Tut del 
 
 London. John. Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 88 
 
 Fig. 175. Itch-insect, female (Sarcoptes scabiei), x 60. 
 
 The Itch-insect belongs to the same family as the Cheese- 
 mite. The parasite is chiefly remarkable for causing the 
 disease called the Itch. The description of the parasite is as 
 follows : Head small,, somewhat narrowed in front ; mandi- 
 bles toothed; anterior two pairs of legs separated from the 
 posterior by a considerable interval : legs short, the anterior 
 two pairs with acetabula or adhesion-disks, 5 -jointed; the 
 posterior 3-jointed, the last joint terminated by a long seta 
 and without acetabula. Male insect about half the size of 
 the female, and with acetabula to the hindermost pair of legs. 
 
 The parasite shows best when mounted in a cell with chlo- 
 ride of calcium or glycerine. 
 
 Fig. 176. Parasite of Watchman-Beetle (Gamasus coleo- 
 ptratorum) , x 20. 
 
 Another parasite of the order Acarina is commonly found 
 on the Dung- or Watchman-Beetle (Geotrupes stercorarius] 
 as it is popularly called. The description of the species is as 
 follows : Anterior coxse attached at a little distance from 
 those of the second pair ; tarsi with two claws and an elegant 
 caruncle ; palpi free, filiform ; mandibles chelate ; ocelli none 
 or indistinct. 
 
 The parasite may be cleaned, dried under pressure, and 
 mounted in balsam as usual ; or it may be mounted in a cell 
 with chloride of calcium, acetic acid, or glycerine. 
 
Fig. 177- 
 
 ',c.K.Maiim. ad.nat del 
 
 London. .John. VaTL Voorst MDCCCLXX 
 
MICROSCOPIC OBJECTS. 
 
 Fig. 177. Raphides from the Hyacinth (Hyacinthus orien- 
 talis), x20Q. 
 
 Raphides are minute crystals, chiefly found in the cellular 
 tissue of plants ; they are most abundant in the Natural 
 Orders Liliacese, Cactacese, Polygonaceae, Orchidacese, &c. 
 Most of the forms show well under polarized light. They 
 are composed of the various salts of lime, viz. the oxalate, 
 carbonate, sulphate, and phosphate of lime. The following 
 tests for these raphides may be useful : Upon the appli- 
 cation of a small drop of acetic acid, the presence of the 
 phosphate or carbonate is immediately perceived, as both 
 of these salts dissolve with effervescence, while neither the 
 oxalate nor the sulphate is altered : for their tests, see 
 fig. 179. To distinguish the phosphate from the carbonate, 
 an excess of ammonia must be added, when, if phosphate 
 of lime is present, it will be developed as minute granular 
 matter. 
 
 Fig. 178. Raphides from Turkey Rhubarb (Rheum pal- 
 matum), x 200. 
 
 These raphides consist of oxalate of lime, each stellate 
 group being composed of a number of rectangular crystals, 
 so arranged by the natural deposition of the salt in any 
 single cell as to partake of the stellate form. An artificial 
 formation of these stellate crystals may be obtained by placing 
 rice-paper or elder-pith in a solution of chloride of calcium, 
 exhausting the air in the cells by placing under an air-pump, 
 then straining off the chloride, and adding a saturated solution 
 of oxalic acid ; after which, occasional stellate crystals will 
 be found. This experiment may be tried with the other 
 salts of lime. 
 
 Raphides are best seen when mounted in Canada balsam. 
 
Fig. 179. 
 
 Fig. ISO. 
 
 .id oat del Didcinso* 
 
 Lond OIL Jc.hu. l r an Voor j t . MD C C C LJCX . 
 
MICROSCOPIC OBJECTS. 90 
 
 Fig. 179. Raphides in the Cuticle of the Onion (Allium 
 Cepa), x 120. 
 
 The raphides in this cuticle consist of crystals of oxalate 
 of lime. They are drawn as seen under polarized light. 
 
 On testing them with sulphuric acid, minute crystals of 
 sulphate of lime are formed (see fig. 182), the sulphuric acid 
 having a greater affinity for the lime than the oxalic acid has. 
 If the crystals had been composed of sulphate of lime, scarcely 
 any change would have been perceived. 
 
 The tests for the carbonate and phosphate of lime are men- 
 tioned under fig. 177. 
 
 The cuticle is best seen when mounted in balsam. 
 
 Fig. 180. Raphides in the Sepal of a Geranium (Geranium 
 Robertianum), x 200. 
 
 The minute stellate crystals which occur in such large 
 numbers in the sepals &c. of most of the species of this genus 
 (Geranium), are composed of oxalate of lime. The presence 
 of raphides in any plant is easily ascertained by the use of 
 the polariscope, as all the forms polarize well. 
 
 It is not known that these vegetable crystals are of use in 
 the nutrition or structure of plants ; but they are no doubt 
 caused in an accidental manner, by the various acids meeting 
 with calcareous matter, uniting with it, and forming these 
 vegetable salts. 
 
 The sepal may be placed in turpentine, and mounted in 
 balsam in the usual manner. 
 
ig. 181. 
 
 Fiq. 
 
 loadou. JotuxVanVocirat MDCCCI3CX. 
 
MICROSCOPIC OBJECTS. * 91 
 
 Fig. 181. Crystals of Carbonate of Lime, x 80. 
 
 Chalk (see fig. 102), marble, limestone (figs. 191, 192, 194), 
 coral, &c. are composed of carbonate of lime. It also occurs 
 in bone, shells, &c., and is, moreover, often found in the animal 
 secretions. From it all the salts of lime may be formed. 
 
 The drawing illustrates the various forms of the crystals as 
 seen under polarized light. 
 
 These crystals may be mounted in balsam. 
 
 Fig. 182. Crystals of Sulphate of Lime, x 100. 
 
 The crystals of this salt of lime may be prepared by adding 
 sulphuric acid to chloride of calcium. Or it may be prepared 
 from carbonate of lime by the addition of the same acid. 
 The size of the tufts of needle-shaped crystals varies greatly. 
 The preparation from which the drawing was made was evapo- 
 rated from a hot saturated solution of the salt and mounted in 
 a cell with castor-oil. 
 
 Sulphate of lime is found in its natural state as gypsum, 
 alabaster, selenite, &c. It often exists in hard water, which, 
 on the addition of carbonate of soda, is softened by preci- 
 pitating the lime as a carbonate. The salt is not very 
 soluble in water. 
 
 N 2 
 
Fig. 183. 
 
 .-.K. "4>otn. ad mu del 
 
 London John. Van. "Voorst. MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 92 
 
 Fig. 183. Crystals of Chlorate of Potash, x 40. 
 
 One of the best of the polarizing crystals is chlorate of 
 potash; but other salts of potash are almost equally interesting 
 (see fig. 184). 
 
 To obtain a constant form of crystal from any salt requires 
 a certain amount of practice. The methods vary. Some 
 crystallize best from a saturated solution in alcohol, others 
 in warm or cold water; some, like salicine, require to be 
 fused, &c. ; but for micro-chemical analysis a saturated solu- 
 tion in cold water is perhaps best, as being least liable to in- 
 terfere with the test used. 
 
 The crystals are drawn as seen under polarized light. 
 
 Fig. 184. Crystals of Bichromate of Potash, x 40. 
 
 From a hot saturated solution of this salt in water, beau- 
 tiful feathery crystals are formed, which, together with many 
 other crystals, have the property of analyzing polarized 
 light (see fig. 185). To show this power well, the crystals 
 of this and of the other salts, such as the nitrate of potash, 
 sulphate of magnesia, &c,, are best mounted in balsam. 
 
 Although many crystals can scarcely be mounted at all on 
 account of their deliquescence, still the majority may be 
 mounted in castor-oil, glycerine, or Canada balsam, and 
 many others may be mounted dry. 
 
Fig. 185. 
 
 Fig. 186. 
 
 *,- 4 H.MMtin. alBAtdd. Dickinson. 
 
 London. John Van Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 93 
 
 Fig. 185. Crystals of Oxalic Acid, x 40. 
 
 As mentioned at fig. 184, some crystals have the power of 
 analyzing polarized light. Sulphate of magnesia, which 
 crystallizes somewhat similarly to oxalic acid, can therefore 
 scarcely be distinguished from it, either in regard to its 
 form or power of polarization. But by adding a drop from 
 the test-bottle of chloride of calcium, the sulphuric acid of 
 the sulphate of magnesia, having a greater affinity for the 
 lime than for the magnesia, combines with it, and forms tufts 
 of the needle-shaped crystals of sulphate of lime (see fig. 182) ; 
 while upon applying the chloride of calcium to the oxalic 
 acid, rectangular crystals of oxalate of lime are chiefly formed. 
 
 The crystals are best seen when mounted in balsam. 
 
 Fig. 186. Feathery Crystals of Boracic Acid, x 40. 
 
 These crystals may be prepared as follows : To a hot 
 saturated solution of borax in water, add | part of sulphuric 
 acid ; as the liquid cools, crystals of boracic acid are deposited 
 at the bottom of the test-tube. The mother liquor must 
 then be poured off, and the crystals dried. If the feathery 
 form is wanted, they must then be dissolved in alcohol, a 
 drop evaporated on a glass slide, and castor-oil immediately 
 applied. Next cover with thin glass, and seal the cover as 
 usual. Even with these precautions the crystals will not 
 often keep long, as they are extremely deliquescent. 
 
 If the solution of borax be treated with phosphoric acid, and 
 the water mixed with the crystals deposited from the mixture 
 be evaporated on the slide, minute disks will occasionally be 
 found. When mounted in Canada balsam and examined 
 under polarized light, crosses will be observed rotating round 
 the centres of these as the polarizer is moved. 
 
Fig. 
 
 Fio. 1S8. 
 
 aiaaJ.ilel. Ijicjcmsoa, 
 
 london. Join. Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 94 
 
 Fig. 187. Plumose Crystals of Quinidine, x 20. 
 
 Quinidine is an alkaloid or vegetable alkali, found in Peru- 
 vian bark, and usually associated with quinine, which it 
 closely resembles. It is not readily soluble in water, but 
 freely in alcohol. The solution, when evaporated, yields the 
 plumose crystals, the great beauty of which, under polarized 
 light, has caused me to draw the reader's attention to the same. 
 
 The crystals show best when mounted in balsam. 
 
 Fig. 188. Crystals of Salicine, x 12. 
 
 These crystals present the same appearance of rotating 
 crosses as the crystals of boracic acid, mentioned at page 93. 
 The method of preparation is, to evaporate from a hot solu- 
 tion in alcohol, or to fuse a small quantity of the salicine 
 over a gas-jet or spirit-lamp until it dissolves, then to run 
 the semifluid mass over the slide; and generally the disks 
 will appear upon the cooling of the glass. If deposited from 
 a solution, it is often found to be the best plan to confine the 
 drop with a wall of varnish or thick gum previously dried. 
 Other forms of interesting crystals which exhibit the cross 
 are boracic acid, sulphate of cadmium, oxalurate of am- 
 monia, Sec. 
 
 Some of the crystals which exhibit the cross have been 
 drawn in fig. 181. The crystals of salicine are best seen 
 when mounted in balsam. 
 
Fig. 189. 
 
 . 190. 
 
 Jh.c.H.Martbo. ad aar del 
 
 j.. Johr. Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 95 
 
 Fig. 189. Section of Sandstone from Cherbourg Works, 
 France, x 40. 
 
 The drawing is taken from the section of this rock as seen 
 under polarized light. This rock is a true siliceous sand- 
 stone, and is composed of subangular fragments of nearly pure 
 quartz, cemented together by a small amount of siliceous 
 matter ; it also contains occasional specks of clay and oxide 
 of iron. 
 
 The microscopical investigation of rocks is of great value 
 to the geological student. 
 
 Fig. 190. Siliceous Infusorial Earth from Bilin, Bohemia, 
 
 x400. 
 
 There are found in many parts of the world rocks composed 
 almost entirely of minute siliceous skeletons of an order of 
 confervoid Algae called Diatoms (compare the drawing with a 
 recent form of Diatom represented at fig. 98) . These minute 
 organisms were long thought to belong to the animal kingdom; 
 and it is only within the last few years that they have been 
 thoroughly studied and classified. 
 
 This rock, like chalk, belongs to the sedimentary formations. 
 
al naJ: del. 
 
 Louden John. Van VOOTS t . MDCCCIXX. 
 
MICROSCOPIC OBJECTS. 96 
 
 Fig. 191. Section of Eocene Nummulitic Limestone from 
 Gerona, x 6. 
 
 This section,, together with that represented in fig. 192, 
 belongs to the calcareous division of rocks. It is a sedimen- 
 tary formation. 
 
 The Nummulites seen in this section are Foraminifera; 
 and the limestone itself is an important member of the 
 Eocene formation, being well developed throughout an exten- 
 sive area in Southern Europe, and even still further eastwards 
 to India. 
 
 Fig. 192. Foraminifera in the lowermost Bed of Carboni- 
 ferous Limestone, from Bristol, x 20. 
 
 This limestone, which often attains a great thickness, is 
 tolerably compact and argillaceous, and retains in a great 
 measure unaltered the structure due to sedimentary deposi- 
 tion, so that the organic remains are well preserved. Amongst 
 the Foraminifera is the genus Fusulina. Compare the forms 
 with the comparatively recent Foraminifera as seen in figs. 
 103, 104, &c. 
 
 It is a sedimentary formation. 
 
Fig. 193, 
 
 Fig. 194- 
 
 Jh.o.H. Maitm. ad -oat.del 
 
 London: John Van. Voorst. MDCCCLXX. 
 
MICROSCOPIC OBJECTS. 97 
 
 Fig. 193. Section of Oolitic Argillaceous Shale from Arica, 
 Peru, x40. 
 
 This rock belongs to the oolitic system, so called from 
 most of the rocks having the appearance of minute round 
 bodies similar to the eggs of fish, as in the figure, this appear- 
 ance arising from the globular deposit of carbonate of lime 
 around grains of sand. 
 
 It belongs to the sedimentary formations. 
 
 Fig. 194. Section of Marble taken from the Temple of Diana 
 at Ephesus, x 20. 
 
 The beautiful appearance of this rock under polarized light 
 can scarcely be appreciated from the drawing, as the several 
 colours of the various particles are necessarily wanting. 
 
 It belongs to the metamorphic rocks. 
 
APPENDIX. 
 
 THE following notes and remarks will be found useful as 
 a slight guide to the preparation and mounting of objects. 
 The student must not be discouraged at his want of skill if 
 he does not succeed even after three or four attempts ; for, 
 like most things, success conies with patience and practice. 
 The things chiefly required are patience, delicate touch, 
 and good eyesight; if these are combined, success is cer- 
 tain. Delicacy of touch is generally acquired in time; so 
 the want of that need not discourage. The first thing, of 
 course, is the choice of a working microscope. There are so 
 many good makers that it is scarcely necessary to mention 
 any particular name; but, perhaps, the cheapest is Field's 
 (of Birmingham) Prize Microscope ; the cost is three gui- 
 neas; and Students' Microscopes from about 5 are made 
 by the best opticians : for a superior article, as the cost 
 increases, Smith and Beck's Popular Microscope, price 10, 
 will be found a good working instrument. To this micro- 
 scope may be added superior object-glasses &c., if wanted. 
 The better microscopes range from this price up to about 
 .190. The next thing to consider is the apparatus that 
 the student will require for observing and mounting the 
 various structures that may be taken from the vegetable and 
 other kingdoms. Having decided upon the choice of a 
 
100 MICROSCOPIC OBJECTS. 
 
 microscope, some of the following apparatus will be re- 
 quired : 
 
 1-inch object-glass. Condenser. Micrometer*. 
 
 -inch object-glass. Polariscope. Live-box. 
 
 A eye-piece. Spectroscope *. Paraffin lamp. 
 
 B eye-piece*. Parabolic reflector*. Fiddian's lamp *. 
 
 N.B. Those articles that are marked with an asterisk may be procured 
 gradually, together with the higher powers &c. 
 
 The following tools &c. must also be purchased or made at 
 the same time : 
 
 An air-pump. 
 
 Propagating or bee-glasses, three or four. 
 
 The cup parts of broken wine-glasses j the bottoms may also be used as 
 covers. 
 
 Dipping- tubes, made by holding glass tubes in a gas-jet until soft, and 
 then drawing out to a fine point. 
 
 Test-tubes : each of these may have a small dipping- tube placed in the 
 cork, so as to reach to the bottom. 
 
 Forceps, one or two. 
 
 Camel's-hair pencils, various sizes. 
 
 Scalpels, two or more. 
 
 Razor mounted in wooden handle. 
 
 Scissors, two pairs ; one fine-pointed, one common. 
 
 Pneumatic trough or a large globe or dish for holding waste water, in 
 which to wash slides, test-tubes, c. 
 
 Needles, three or four sizes, mounted in small cedar handles. 
 
 One large ditto ground down to a cutting-edge (like a chisel), for sepa- 
 rating and cutting minute fibres &c. 
 
 A fine thread of spun glass fixed in a handle, used for isolating minute 
 objects, such as Diatoms &c. 
 
 Spirit-lamp. 
 
 Tripods, two or three, or a retort-stand. 
 
 American paper-clips (these can be procured at most stationers'). 
 
 Small white porcelain cups: can be obtained of any artist's colourman. 
 
 Pumphrey's ebonite cells. 
 
 Watch-glasses. 
 
 Glass funnel. 
 
 Turn-table. 
 
 Section-cutter. 
 
 Pill-boxes (various sizes). 
 
 Liebig's extract-of-meat jars (empty). 
 
 Writing diamond. 
 
 Small homoeopathic bottles. 
 
APPENDIX. 101 
 
 Files. 
 
 Fine saw mounted in wooden handle. 
 
 Punches, two or three. 
 
 Hammer. 
 
 Wooden block. 
 
 Pliers, two pairs, one of them cutting. 
 
 Old knives. 
 
 Glass slips, 3x1 inch. 
 
 Thin glass : squares \ oz., circles ^ oz. 
 
 Wire, &c. 
 
 The following chemicals &c. will also be wanted : 
 
 Solution of gum arabic in bottle with brush in the stopper of the same. 
 Glass bottle with a glass tube in the stopper, tilled with Canada balsam. 
 Distilled water (with a lump of camphor in it to prevent any confervoid 
 
 growths &c.) in a large stoppered bottle. 
 Liquid potassa fusa, strength 1 part potassa to 8 parts water. 
 Distilled Canada balsam. 
 
 Turpentine. Chloride of calcium. 
 
 Ether. Silicate of potassa. 
 
 Ammonia. Lime-water. 
 
 Benzole. Test-papers. 
 
 Chloroform. Sulphuric acid. 
 
 Glycerine. Nitric acid. 
 
 Alcohol. Hydrochloric acid. 
 
 Methylated spirit. Acetic acid. 
 
 Essential oil of lemon. Gum-dammar. 
 
 Syrup. Marine glue. 
 
 Judson's dyes, three colours. Caoutchouc cement. 
 
 Nitrate of silver. Berlin black (a varnish). 
 
 Iodine. Gutta percha, &c. 
 
 Having now mentioned nearly all the things requisite for 
 an amateur, we will next proceed to the preparation and 
 mounting of a few objects, so as to give the reader an insight 
 into the matter. 
 
 There are three forms of mounting chiefly used, viz. in 
 balsam, dry, and in fluid or semifluid. All these methods 
 should be tried upon the matter that may come into the 
 student's hands, as the full structure and beauty is often 
 lost from the specimen being mounted in an imperfect 
 manner. Canada balsam, although it has its faults, appears 
 to be at present the most reliable substance in which the 
 
 p 2 
 
102 MICROSCOPIC OBJECTS. 
 
 majority of transparent objects may be mounted. Most in- 
 sects and the parts of the same are mounted in balsam ; 
 they must be placed in the potassa solution from six hours 
 (or less) to as many days, according to the softness or 
 hardness, or transparency or opaqueness, of the object ; ex- 
 perience will give the time. They must then be put under a 
 slight pressure so as to squeeze out part of the extraneous 
 matter ; replace in the potassa solution for a short time, then 
 put them under increased pressure until cleared of the rest of 
 the contents, when they must be placed in a large quantity of 
 warm water for a few hours. It is best not to touch the object 
 at this stage even with a camel-hair brush ; but the vessel of 
 water must be repeatedly shaken and extra water added, so as 
 to thoroughly clean the specimen from the potassa (this is 
 important) ; it must then be taken out of the water and dried 
 between two slips of glass. All the pressure requisite for 
 a small object is obtained by the use of the American 
 paper-clips ; but if the object is large and thick (as, e.g., 
 many of the beetles), the regulated pressure of a small 
 screw-press is necessary. After it has been well dried 
 (which, of course, will take from a few hours to as many 
 days, according to the size and nature of the object) it 
 must be soaked in turpentine, or, what is better, distilled 
 Canada balsam, until moderately transparent ; if small, it 
 must not be taken from the glass slide. A slip of glass of 
 the recognized size, 3x1 inches, must be taken, a drop 
 of balsam (the size of the drop proportionate to the size 
 of the object) placed with the glass tube in the centre of the 
 slide ; the drop must then be made to spread slightly by the use 
 of moderate heat, the object placed in it, arid the thin glass 
 cover applied with care. If any air-bubbles appear, they will 
 generally be found to have dispersed after a day or two ; and un- 
 less the object is valuable, it is best never to attempt to 
 remount it. As the patience of the learner would be greatly 
 tried during the process, it is always better to begin again 
 with a fresh specimen. The balsam takes a long time to dry if 
 left to itself, which is best ; but if the objects are wanted 
 early, they may be dried over a gas-jet, or by any other plan, so 
 
APPENDIX. 103 
 
 that the heat be about 50 C. ; this temperature will not do 
 for all objects. The next thing is to finish the slide neatly. 
 Paper covers are sold for this purpose ; but the best plan for 
 durability is simply to finish with a ring of Berlin black var- 
 nish ; or even this may be omitted in some cases ; the advan- 
 tage of this plan is that the slides can be kept much cleaner 
 &c. The white paper label can then be affixed with the 
 English and scientific names, also what fluid &c. it is mounted 
 in, and the date of the preparation. It can then be stored, if 
 money is an object, in the cheap rack-boxes sold by Mr. 
 Wheeler and other opticians at prices varying from sixpence 
 upwards (these boxes are not covered with cloth) ; the boxes 
 may then be numbered and placed on shelves in the same 
 manner as books', whereby the objects are kept in a horizontal 
 position. 
 
 Fluids had, until lately, greatly gone down in the esti- 
 mation of microscopists as vehicles in which to mount various 
 specimens ; but glycerine and the more recent, if not so 
 useful, substance silicate of potassa, which appears to be a 
 very favourable semifluid for mounting certain structures, 
 have again caused them to be used ; and there are now var- 
 nishes and cements, such as the india-rubber and shellac 
 cement, which, with care, will hermetically seal fluid prepara- 
 tions for many years. We will treat of the process. Take 
 a slide, centre it on the turn-table, charge a earners hair brush 
 with the india-rubber cement, place the table in action and a 
 ring or circular cell of the cement is formed, varying in depth 
 according to the thickness of the fluid and the quantity used ; 
 turn a number of these cells and put aside to dry, to be used 
 as wanted. With a pipette take from the alcoholic and cam- 
 phor preservative fluid a sufficient quantity to fill the cell, 
 soak the object in proof spirit for an hour or so to exhaust 
 the air (it is better if the object has been kept in alcohol, see 
 fig. 109) ; or it may be done in much less time under the air- 
 pump ; it is then placed in the centre of the cell, the thin glass 
 cover placed gently over it, so as to exclude all air-bubbles ; 
 soak up all the surplus fluid with blotting-paper, centre the 
 slide again on the turn-table, and seal the cell with a ring of 
 
104 MICROSCOPIC OBJECTS. 
 
 the liquid india-rubber cement ; dry, and finish with Berlin 
 black varnish, then label as usual. Whatever fluid is used, the 
 process is nearly the same ; but when glycerine or chloride of 
 calcium is used the cell must be sealed either with Bell's 
 cement or a saturated solution of gum-dammar in benzole ; 
 when the silicate of potassa is used it is hardly necessary to 
 seal the cell at all, as the fluid dries at the edges and seals 
 itself. 
 
 The next form of mounting is the dry system. A cell 
 made of cardboard, gutta percha, ebonite, &c. is cemented to 
 the centre of a glass slip, sufficient Berlin black is then used 
 to cover the bottom of the cell, a small drop of pure gum or 
 any good cement is placed in the centre; the object, which 
 has also a minute quantity of the same cement on it, is then 
 fixed exactly on the same spot, and the slide is left under a 
 bell-glass to dry, after which a circle or square of thin glass is 
 closely cemented to the top of the cell ; the slide may then 
 be finished with any black varnish, or it may be covered with 
 any of the paper covers. If the specimen is to form a trans- 
 parent object, the Berlin black must be left out of the cell ; 
 and it is best not to cement the object to the glass slide, as 
 the cement often shows through and spoils the appearance ; 
 the object may be fixed by the slight pressure of a thin glass 
 cover in a shallow cell. 
 
 In the mounting of objects, great care must be taken to 
 show the structural characteristics of the specimen; for if 
 this is attended to, a greater amount of valuable information 
 will be obtained even from a "common object." 
 
 Alga, Confervoid fyc. These show well when mounted in 
 a preservative fluid consisting of 1 part alcohol to 7 water, 
 mixed with an equal quantity of a cold saturated solution 
 of camphor in distilled water. There are some seaweeds 
 with their fructification that show best when mounted in 
 balsam ; but if glycerine or any other fluid which causes a 
 strong exosmotic action on the cell-wall be used as the pre- 
 servative fluid, it must be done by its gradual addition to the 
 water in which the Algse are contained, so that its action on 
 the cell-wall and protoplasm will not be so abrupt as to cause 
 
APPENDIX. 105 
 
 any rupture of the same. A solution of alum is also often 
 used in the preservation of some of the Algae : a fluid still 
 better is the acetate of alumina, prepared by dissolving alum 
 in acetic acid, crystallizing by evaporation, and to a satu- 
 rated solution of this salt adding four or five parts of distilled 
 water ; or the acetate of alumina may be dissolved in the 
 glycerine. 
 
 Bone, Teeth, tyc. Sections of these substances, if required 
 to be mounted dry, are best made by cutting a thin section 
 with the fine saw, and finishing by grinding down with a file 
 until they are made as transparent as possible ; they may then 
 be mounted in a dry cell. The sections are best ground by 
 fixing them to a slip of glass with strong balsam ; the better 
 methods of preparation are: to cut a thin section after mace- 
 ration in hydrochloric acid diluted with two parts water, then 
 to mount in a cell with a fluid composed of acetic acid 1 part, 
 water 2 parts ; or the broken bone, tooth, &c. may be placed 
 in a fluid of 1 part glycerine, 1 part water, for a few hours, 
 then add gradually a mixture of glycerine and acetic acid 
 equal parts ; after a short time thin sections may be cut with 
 a fine scalpel. Mount in a preservative fluid, acetic acid 1 part, 
 water 3 parts ; or it may be mounted in glycerine, or glycerine 
 and acetic acid equal parts. 
 
 Crystals. The formation of crystals, from saline and other 
 solutions, under the microscope yields an extremely interesting 
 and useful study, for example, the beautiful appearance of 
 the crystals of chloride of ammonium caused by holding for a 
 few seconds a glass slide that has had one drop of hydrochloric 
 acid spread over the surface, over the fumes or vapour 
 of ammonia : upon the gradual evaporating of this thin 
 film of fluid, fine feathery crystals are formed ; they are 
 produced by the ammonia combining with the hydrochloric 
 acid. These crystals may often be developed from the human 
 breath, more especially in certain forms of disease. 
 
 Some forms of crystals are best produced by placing a drop 
 of the solution under a thin glass cover and letting the fluid 
 evaporate gradually. The majority of crystals formed from the 
 various salts &c. are best mounted in castor -oil and sealed 
 
106 MICROSCOPIC OBJECTS. 
 
 with the gum-dammar cement ; many show well when 
 mounted in a solution of balsam in chloroform. 
 
 Desmidie<e fyc. For the mounting of these lower forms of 
 vegetable life, see Algae; they are best collected by taking 
 the green scum from the margins of ponds situated in open 
 and exposed districts, and placing this green matter in a 
 white saucer nearly full of water : shade, all but an inch or so, 
 from the surrounding daylight; and in the space of a few 
 hours, if fresh, the Desmids will be found massed at the place 
 that has been left exposed to the light ; with a pipette they 
 may then be separated from the surrounding substances, and 
 mounted in a shallow cell with one of the preservative fluids. 
 They are found in the greatest quantity in the later summer 
 and the autumn months. 
 
 Diatoms are collected in nearly the same manner as Des- 
 mids, from which they may be distinguished by their light 
 brown colour; they are often found growing in tufts upon 
 the marine and the freshwater Algae. Their mode of prepara- 
 tion is rather difficult ; but, in a few words, the following will 
 be found the best process : Burn the deposit in a platinum 
 spoon until it assumes the appearance of a white ash, then 
 boil in nitric acid for a short time, when most of the siliceous 
 valves will be found quite clean : the large glass tubes used 
 by chemists for collecting hydrogen and other gases will be 
 found, on account of their length, of great assistance in sepa- 
 rating the species according to their specific gravities ; they 
 may then be mounted dry, in balsam, or in some fluids, but 
 not silicate of potassa. 
 
 The name of the species of Diatom, if known, must be im- 
 mediately written on the slide. This rule holds good with all 
 specimens, as, if a note is not made at the time, it is liable to 
 be forgotten. 
 
 Entozoa. Many of this class of animals exhibit their ana- 
 tomy best when mounted in glycerine ; they also mount well, 
 after preparation, in balsam. If surrounded by germinal mat- 
 ter, the use of the carmine or other dye to be used as a stain 
 will cause the parasite to appear better, the dye staining the 
 surrounding mass and leaving the animal untouched : an 
 
APPENDIX. 107 
 
 example of this class is seen at fig. 115. An interesting species 
 for observation will be found in the Anguillula glutinis, found 
 in sour paste. 
 
 Ferns and Mosses. The investigations into the structure 
 of the minute reproductive organs of these plants form an 
 interesting branch of microscopy. Mosses (more especially at 
 the time of the year when nature partially hides her glory) 
 may be taken up as a special object of study ; for their struc- 
 tural peculiarities are developed chiefly in winter. Many of 
 the smaller species may be mounted entire, after soaking for 
 a short time in water and draining off the same : they show 
 well when mounted in the silicate of potassa ; but most of the 
 minute characters show best in balsam. The parts of the 
 fronds of various species of Ferns which exhibit the sori show 
 best when mounted dry. 
 
 Lichens, when entire, are mounted dry; but, to show the 
 apothecia &c. well, the sections of the thallus must be mounted 
 in glycerine or balsam. 
 
 Fungi. Sections of spores &c. are generally best when 
 mounted in the preservative fluids, as recommended for the 
 Algse ; but many of the micro-Fungi may be mounted in situ 
 in a dry opaque cell ; and some of the brands &c. show best 
 when mounted in balsam. 
 
 Leaves and Petals. The cuticles of these parts of plants 
 form a large range for investigations. Most cuticles are pre- 
 pared by boiling the leaf in a fluid made by adding about four 
 parts of water to one of nitric acid ; but the proportion must 
 vary according to the nature and strength of the leaf. After 
 the cuticle is separated by boiling in this fluid, it must be 
 floated off from the waste tissue, delicately washed with a fine 
 cameVs-hair pencil, and mounted in a suitable fluid according 
 to its thickness &c., if thick, in glycerine or balsam ; if thin, 
 in any of the fluids recommended for the Algae &c. The cuti- 
 cles of the petals are best when torn from the surface ; but for 
 petals I prefer the colouring- matter to be nearly obliterated 
 by the use of ether; then add weak sulphuric acid, dry, and 
 mount in balsam ; or some show best when mounted dry. 
 
 Most of the other vegetable tissues, such as spiral-vascular, 
 scalariform, &c., are best mounted in glycerine &c. 
 
108 MICROSCOPIC OBJECTS. 
 
 Spicula $c. See figs. 107 and 108. 
 
 Starches. Many of these may be mounted in silicate of 
 potassa, care being taken to moisten the starch first, or air- 
 bubbles will be formed, which are difficult to get rid of in this 
 substance without the use of the air-pump ; if required for the 
 polariscope, balsam is best. For other remarks, see the starches 
 (figs. 53, 54, &c.). 
 
 Insects, parts of, &c., are best when mounted in balsam, 
 although some of the smaller ones perhaps exhibit their struc- 
 ture better when mounted in acetic acid, 1 part acid to 2 parts 
 water ; they may be mounted in one of Pumphrey's ebonite 
 cells, or in a cell made of the india-rubber cement ; in both 
 cases this is the substance with which to seal the cell. For 
 other information on mounting &c., see Insects. 
 
 Palates, or tongues of the Gasteropoda, a class belonging 
 to the Mollusks, are generally dissected from the animal, 
 cleaned with potass, washed, dried, and mounted in balsam ; 
 they are then generally seen under the polariscope. Some, 
 like the whelk's tongue, require to be slit up the centre, 
 spread out and dried ; they show well when mounted in gly- 
 cerine. 
 
 Zoophytes, Rotatoria, fyc. show best when mounted in a 
 fluid as nearly as possible like their native element. 
 
 White slabs to be used for dissections &c. are made of the 
 white gutta-percha enamel (sold as a tooth-stopping) mixed 
 with white wax; after this substance is run out into slabs 
 about the T V of an inch in thickness, they may be cut up and 
 used at the bottom of the cells when it is required to exhibit 
 any particular dissection in its natural position; for rough 
 purposes ordinary gutta percha may be used, mixed with wax 
 in the same manner. For dissections under water the gutta- 
 percha and wax substance must be melted at the bottom of a 
 deep white vessel ; the porcelain dishes that photographers use 
 will do for this purpose ; a common dish, if deep, may be used. 
 
 In staining tissues the germinal or growing matter is 
 coloured, and the formed or mature matter is not. But, then, 
 do not use Judson's dyes ; they dye every thing : see Demodex 
 (fig. 173), Eritozoa, &c. 
 
APPENDIX. 109 
 
 The addition of weak hydrochloric or nitric acid is useful 
 for breaking up cellular tissue &c. 
 
 Thin sections of most substances can be well cut by soak- 
 ing them in the india-rubber cement, which must be allowed to 
 dry ; the sections may then be made with a razor or scalpel. 
 
 For the observation of any object the student must place 
 the same between a glass slip and a piece of thin glass. Water 
 is the fluid most generally used for rough observation ; but 
 this must be left to observation and experiment. And in the 
 mounting of objects common sense must be used; for instance, 
 an opaque-looking object is generally best mounted in balsam, 
 as it has good refractive powers, and a transparent substance 
 is generally best seen when mounted either dry or in fluids. 
 
 Dust must be carefully kept from all preparations whilst 
 in progress. 
 
 The author must now conclude, trusting that his readers 
 will find these rough notes useful, and that the study of some 
 of the hidden forms made by Divine art will lead him to 
 search further for the marvellous beauties of nature. 
 
ERRATA. 
 
 Page 10, fig. 20, line 8, for circulation read nutrition. 
 
 Page 54, fig. 108, line 7, for diluted potassa fusa, read in a diluted solu- 
 tion of potassa fusa. 
 
 Page 63, fig. 126, line 7, for therefore &c., read therefore each of the 
 facets receives an image of the object before them. 
 
 Page 64, fig. 128, line 9, for the rasp-like bodies in &c., read the rasp- 
 like bodies of the male insect in the &c. 
 
 86, fig. 171, for Order Acarind read Order Acarina. 
 
INDEX. 
 
 Page 
 
 Acarus domesticus 86 
 
 Acrogen, section of an 38 
 
 Agrion virgo, head of larva of 68 
 
 Alder, sections of 32,33 
 
 Algge 47,48,49,50 
 
 Amoeba 51 
 
 Animalcula 51,58,59 
 
 Annulus of a moss 42 
 
 Anoplura, order 82,83 
 
 Antenna of cockchafer 62 
 
 Anthomyia, a house-fly, eggs of ... 79 
 
 Antlia of a moth 71 
 
 Ant-lion, larva of 68 
 
 Aphaniptera, order 80,81 
 
 Aphis, hop- 66 
 
 Apis, parts of 73,74,75 
 
 Apple, cells of 3 
 
 Aracknida, class 84,85,86,87,88 
 
 Araneida, order 84,85 
 
 Araucaria, cuticle of 12 
 
 Arbutus, pollen of 22 
 
 Argillaceous rock 97 
 
 Asparagus-beetle 60 
 
 Batrachospermum moniliforme, an 
 
 alga 48 
 
 Bauhinia, transverse section of ... 30 
 Beaded hairs from stamen of Tra- 
 
 descantia 17 
 
 Bee, leg of 74 
 
 Bee, parasite of 86 
 
 Bee, sting of 75 
 
 Bee, tongue of 73 
 
 Bichromate of potash, crystals of. . . 92 
 
 Blight, maple- 1 
 
 Blow-fly, spiracle of 77 
 
 Blow-fly, tongue of 76 
 
 Boracic acid, feathery crystals of... 93 
 
 Bot-fly, egg of 79 
 
 Botrytis, from leaf of Begonia 47 
 
 Brake Fern, oblique section of. 6 
 
 Branched hairs from Great Mullein. 16 
 
 Brand from Bramble-leaf 46 
 
 Bree/e-fly, spiracle of 77 
 
 Bryum hornum, organs of 43 
 
 Bug, lancets of 
 
 Burnet-moth, scales of 71 
 
 Cabbage, hairs from 17 
 
 Cactus, spiral-fibre cells from 9 
 
 Calcareous rocks, sections of 96 
 
 Capsules of mosses 41,42 
 
 Capsule of scale-moss 43 
 
 Carbonate of lime, crystals of 91 
 
 Carrot, starch from ... 29 
 
 Celandine, laticiferous tissue from 10 
 
 Cells from apple 3 
 
 Chalk, f oraminifera from 51 
 
 Cheese-mite 86 
 
 Chestnut, starch from 28 
 
 Chlorate of potass, crystals of 92 
 
 Chlorococcum vulgare, an alga ... 2 
 
 Chrysanthemum, cuticle of 11 
 
 Cimex lectularius, lancets of 67 
 
 Closterium Leibleinii, a desmid ... 50 
 
 Cluster-cups on pilewort 46 
 
 Cockchafer, antenna of 62 
 
 C ocoa-nut palm, transverse section of 36 
 Coleoptera, order, parts of, &c. 60, 61, 62 
 
 Collomia, testa of seed of 24 
 
 Compound hairs of plants ... 15, 16, 17 
 
 Convolvulus, pollen of 20 
 
 Copper-butterfly, eggs of 72 
 
 Cork-oak, sections of 30, 31 
 
 Cotton-fibre 16 
 
 Cricket, gizzard of 64 
 
 Cricket, noise-apparatus of 64 
 
 Cricket, tongue of 65 
 
 Cricket, whole insect 63 
 
 Crystals, vegetable and mineral, 
 
 89,90,91,92,93,94 
 
 Cuticles, various 11,12,13 
 
 Cutters of froghopper 67 
 
 Cyclops vulgaris 60 
 
 Cystioercus, head of 57 
 
 Darnel-grass, siliceous cuticle of ... 13 
 
 Dead-nettle, stamens and pistil of.. 22 
 Death's-head moth, spiracle of larva 
 
 of . 70 
 
112 
 
 INDEX. 
 
 Page 
 
 Demodex folliculorum 87 
 
 Diatoma vulgare, natural state of... 49 
 Diptera, order, parts of, &c. 76, 77, 78, 79 
 
 Dragon-fly, head of larva of 68 
 
 Dytiscus, leg of 62 
 
 Dytiscus, spiracle of 61 
 
 Earth-mite, eggs of 87 
 
 Eccremocarp us-seed 23 
 
 Echinus-spine, transverse section of 
 an 57 
 
 Eggs of insects 72, 79, 83, 87 
 
 Elaeagnus, scales of 14 
 
 Elder, longitudinal section of 7 
 
 Elder-pith, transverse section of ... 4 
 Endogen, transverse section of an. . . 36 
 
 Entozoa 57,58 
 
 Eocene nummulitic limestone, from 
 
 Gerona 96 
 
 Epiphyllum, petal of 19 
 
 Equisetum, spores of 40 
 
 Evening primrose, pollen of 21 
 
 Exogen, transverse section of an ... 30 
 Eyes of insects 63, 69, 78 
 
 Fern, scalariform tissue from 6 
 
 Fern, scales of a 13 
 
 Ferns, organs of fructification of, 
 
 38, 39, 40 
 
 Flea, lancets of 81 
 
 Fleas, various species 80, 81 
 
 Foot of a spider 85 
 
 Foot of Scatophaga, a fly 78 
 
 Foraminifera from the Adriatic Sea 52 
 
 Foraminifera from chalk 51 
 
 Foraminifera from the Levant 52 
 
 Foraminifera in the bottom bed of 
 carboniferous limestone, Bristol. 96 
 
 Fritillaria, petal of 20 
 
 Frullania dilatata, a scale-moss ... 44 
 
 Funaria (a moss), parts of 41 , 42 
 
 Fungi, parts of, &c 1,2, 45, 46, 47 
 
 Gamasus coleoptratorum, parasite 
 
 of beetle 88 
 
 Geodia barreta, spicula of 54 
 
 Geranium, petal of 19 
 
 Geranium, raphides in sepal of ... 90 
 
 Geranium, section of leaf of 14 
 
 Gizzard of house-cricket 64 
 
 Gonidia in section of lichen 45 
 
 Gorgonia, spicula of 54 
 
 Hairs of plants 15,16,17 
 
 Head of Cysticercus, an Entozoon.. 57 
 Helophorus granularis, water-weed 
 
 beetle 61 
 
 Hemiptera, order, parts of, &c. 65, 66, 67 
 
 HepaticEC, a family of 43, 44 
 
 Honduras mahogany, sections of. 31, 32 
 
 Horse, parasite of 82 
 
 House-cricket 63 
 
 Human flea, female 81 
 
 Human flea, lancets of 81 
 
 Human louse 82 
 
 Humming-bird hawk-moth, pro- 
 boscis of 71 
 
 Hyacinth, pollen of 21 
 
 Hyacinth, raphides from 89 
 
 Itch-insect 88 
 
 Ivory-nut, section of 9 
 
 Ivory-nut, testa of 24 
 
 Ivy, stellate hairs of 15 
 
 Jute, liber-cells of 10 
 
 Lancets of bug 67 
 
 Lancets of human flea 81 
 
 Lancets of mosquito 76 
 
 Laomedea gelatinosa, a zoophyte ... 55 
 
 Larva of ant-lion 68 
 
 Larva of bot-fly, in the egg 79 
 
 Lastrea Filix-Mas, fructification of 39 
 
 Laticiferous tissue from Celandine.. 10 
 
 Leg of Dytiscus 62 
 
 Leg of honey-bee 74 
 
 Lepidoptera, order, parts of the, 
 
 69,70,71,72 
 
 Liber-cells from jute 10 
 
 Lichen, parts of a 44,45 
 
 Limpet, palate of 59 
 
 Linaria minor, seeds of 23 
 
 Locust, eye of 63 
 
 Louse, human 82 
 
 Lycopodium inaequalifolium, sec- 
 tion of -... 38 
 
 Mahogany, sections of 31,32 
 
 Maize, starch from 27 
 
 Malacca pepper, section of stem of 36 
 Malope grandiflora, section of seed 
 
 of 25 
 
 Mandibles of a spider 84 
 
 Maple-blight 1 
 
 Marble from the temple of Diana 
 
 at Ephesus, section of 97 
 
 Micrasterias denticulata, a desmid 50 
 
 Mosses, parts of, &c 41 , 42, 43 
 
 Moth, scales on the wing of a 71 
 
 Moth, the proboscis of a 71 
 
 Mullein, branched hairs of 16 
 
 Mushroom, spores of 2 
 
 Myrmeleon formicarius, larva of... 68 
 
 Nettle, stings of 18 
 
 Neuroptera, order, parts of, &c.... 68, 69 
 
 Noise-apparatus of cricket 64 
 
 Norfolk-Island pine, sections of.. 34, 35 
 
 Noteus quadricornis, a Rotifer ... 59 
 
INDEX. 
 
 113 
 
 Pat 
 
 Oat, starch from 26 
 
 Oblique section of brake fern 6 
 
 Oncidium, cuticle of 11 
 
 Onion, raphides in cuticle of 90 
 
 Oolitic argillaceous shale, from 
 
 Arica, Peru, section of 97 
 
 Orthoptera, order, parts of, &c. 63, 64, 65 
 
 Osmunda regalis, spore-cases of ... 40 
 
 Oxalic acid, crystals of 93 
 
 Palate of Limpet 59 
 
 Palm, transverse section of a 36 
 
 Parasite of horse 82 
 
 Parasite of starling 83 
 
 Parasite of watchman-beetle 88 
 
 Parmelia parietina, a lichen 44 
 
 Pepper stem , transverse secti on of a 36 
 
 Peristome &c. of a moss 42 
 
 Petals of various flowers 18, 19, 20 
 
 Peziza coccinea, section of 45 
 
 Pilea smilacifolia, section of 37 
 
 Pilewort, cluster-cups on 46 
 
 Pimpernel, petal of .' 18 
 
 Pine-apple, transverse section of ... 3 
 Pinus strobus, longitudinal section 
 
 of ; 7 
 
 Plumose quinidine, crystals of 94 
 
 Plumularia setacea, a zoophyte ... 55 
 
 Pollens, various 20,21,22 
 
 Polycystina, various species of 53 
 
 Polvommatus alexis, a blue butter- 
 fly 69 
 
 Polvpodium vulgare, fructification 
 
 of 38 
 
 Potato, starch from 28 
 
 Prasiola calophylla, an alga 48 
 
 Proboscis of humming-bird hawk- 
 moth 71 
 
 Quinidine, plumose, crystals of ... 94 
 
 Eabbit, head of a parasite of the ... 57 
 
 Raphides, various 89,90 
 
 Rhubarb, spiral - vascular tissue 
 
 from 8 
 
 Rhubarb, transverse section of leaf- 
 stem of 8 
 
 Rice, starch from 27 
 
 Rotatoria 58,59 
 
 Rush, transverse section of 5 
 
 Salicine, crystals of 94 
 
 Sand-bee, tongue of 73 
 
 Sandstone from Cherbourg works, 
 
 France, section of 95 
 
 Sarcoptes scabiei, itch-insect 88 
 
 Sarsaparilla, transverse section of 
 
 stem of 37 
 
 Scalariform tissue 6 
 
 Scales of burnet-moth, in situ 71 
 
 Page 
 
 Scales of plants 13,14 
 
 Section of vegetable-ivory nut 9 
 
 Seeds, parts of, &c 25, 24, 25 
 
 Siliceous infusorial earth, from 
 
 Bilin, Bohemia 95 
 
 Siliceous rocks 95 
 
 Silkworm, trachese of 70 
 
 Simple hairs from cabbage 17 
 
 Skin-parasite, Demodex 87 
 
 Spicula, various 54 
 
 Spider, dissections of, &c 84, 85 
 
 Spine of an Echinus, transverse 
 
 section of 57 
 
 Spines of a starfish 56 
 
 Spines of Spatangus 56 
 
 Spiracle of Dytiscus 61 
 
 Spiracles of insects 61, 70, 77 
 
 Spiral-fibre cells from a Cactus ... 9 
 
 Spiral-vascular tissue from rhubarb 8 
 
 Spirogyra decimina, an alga 47 
 
 Sponge, section of 53 
 
 Spores of an Equisetum 40 
 
 Spores of mushroom 2 
 
 Squamella oblonga, a Rotifer 58 
 
 Stamens and pistil of dead-nettle 22 
 
 Starches, various 26, 27, 28, 29 
 
 Starling, parasite of 83 
 
 Stellate hairs from ivy 15 
 
 Stellate tissue from rush 5 
 
 Sting of bee 75 
 
 Stings from nettle 18 
 
 Sugar-grass, siliceous cuticle of ... 12 
 
 Sulphate of lime, crystals of 91 
 
 Tapioca, starch from 29 
 
 Tetranychus lapidum, eggs of 87 
 
 Thrips physapus, a small fly 75 
 
 Tobacco, hairs of 15 
 
 Tongue of blow-fly 76 
 
 Tongues of insects, various, 
 
 65, 71, 73, 76, 81 
 
 Tortula subulata, capsule of 41 
 
 Tracheae of silkworm 70 
 
 Trichina spiralis, an Entozoon ... 58 
 
 Two-horned scale-moss, capsule of 43 
 
 Vegetable-ivory nut, section of 9 
 
 Vegetable-ivory nut, section of 
 
 testa of 24 
 
 Volvox globator, a confervoid alga 49 
 
 Wasp 73 
 
 Watchman-beetle, parasite of 88 
 
 Water-boatman, wing-case of 66 
 
 Water-plantain, transverse section 
 
 of leaf-stalk of 4 
 
 Water-scorpion 65 
 
 Water-weed beetle 61 
 
 Wheat, starch from 26 
 
 Willow- beauty moth, eggs of 72 
 
114 
 
 Willow, sections of 5, 33, 
 
 Wings, with booklets, of wasp 74 
 
 Woods, various sections of, 
 
 30,31,32,33,34,35,36 
 
 INDEX. 
 
 Page 
 
 Yeast-plant 1 
 
 Yew, longitudinal section of 35 
 
 Zoophytes, two species of 55 
 
 THE END. 
 
 Printed by TAYLOR and FRANCIS, Ked Lion Court, Fleet Street.