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Natural Science. taken place in the Kingdom, Sub-kingdom, Class, Sub-class, Order, Sub-order, Family, Sub-family, Genus, Snb-genus, Species, Sub- species, Variety, and Sub-variety, to which it may belong. The distinctive peculiarity of existing animals as compared with those of past Epochs, therefore, is that their organization is more specialized, so that as we go backward in time the distinctive peculiarities of the natural groups gi-adually disappear, intermediate forms and increasingly generalized or *' synthetic" types continually appear, bridging over apparent chasms. Thus the Genera Fquus and Elephas, each consisting of but a k\\ existing Species and widely separated from each other, and from every other Genus of living animals, are found to be in close relation with many allied and intermediate forms, the remains of which are found in the rocks of the Recent, the Quaternary, and the Tertiary Periods ; the types becoming more and more synthetic as we go backward in time, and the relative size of the brain cavity gradually ( ninishing, until in the earliest Tertiary it becomes comparable to that of the Iteptilia. The most remarkable differentiation in the Equine family is in the * Except certain of the lower Grades in which a whole community is developed from the product of a single egg, hy budding, iubdivision, &c. 3 7/^ ^'' '^' a Jk&aS — OV EVOLUTION. Structure of the foot; passing gradually from the four toed Genus Orohippus of the Eocene, through such intermediate forms as the three-toed genus Anchitherium of the Miocene, and Hipparion of the P.Uocene, which had three toes, but only the middle one well developed, the other two not reaching the ground, to its present representative Equus, including the Horse, Zebra, &c., with its single toed foot. Birds are a highly specialized Class of Vertebrata, haying how- ever closer structural affinities with the Chelonia than would be supposed from external appearance. One of their marked peculiari- ities is that they are all toothless. Few remains of the earlier Birds have yet been found, but among them is Ichthyornis dispar, of the Cretaceous Period, which shews a complete set of teeth ! The embryo of certain living Birds also have teeth, thus illustrating ih« law that the metamorphoses which the existing individual undergoes are representative of those which the group to which it belongs has undergone. In other respects 7. Bispar had well marked Reptilian and even Ichthic characteristics, in other words was of a very synthetic type. The Archceoptetyx macrurus of the Jurassic Period had, in accordance with the same law, still more marked Reptilian characteristics.* Of all Vertebrates the Sub-class Amphibia is the most obviously suggestive and instructive in the metamorphoses which it undergoes after leaving the egg, shewing, in the common Frog, for exam°ple» how a creature approximating to the typical organization of the earlier Fishes, living only in the water, breathing by means of gUls, subsisting chiefly on vegetable food, without limbs but with a muscular system adapted to use the tail in swimming as the sole means of locomotion, develops into an Amphibian without a tail, possessing true limbs of indeed remarkable homological symmetry, well developed lungs and voice, all the change in the circulation of .n,i J» '%} "Ju^** ^?"^' *"^ ^i ^"«^^«« ^'■oa'J- It consists of 20 vertebrae, nonH^n/Jr.f ^'**^'" H°"u« ***" '''^^'' '^*'««« f^'^ feathers are in pairs corres- otUfio.^.ri ^ "•"'"''f' f V^^ vertebrae, and diverge from the axis .,t an angle anfsASinhirh?^'7?/*'°Jl''''^''^^'^' """^^ ^° ^ ^^"'-^ *»th the la.t vertebrae, i^trihnfXl ^^^^'^- ^^^""'^^ "^PP^"^" ^ h^^« a two jointed finger. The breadth of the wing wa. made by feathers as in birds, and not as in a Pterodactyl by an expanded membrane. The feet are like those of Birds. '/ ^'«'-o"a<^»y» ' ROSS — ON EVOLUTION. 8 tlie blood implied by the prcoence of the lunge, and all the great changes in the muscuhir and other systems of organs implied in the use of well developed limbs and in making insects its only food, while other Families of this same Claso illustrate, in the mature condition, almost every stage cf the process by which so great a change is accompliaiied. Nor can it be without a deep significance ihat in all the higl er Vertebrates — in Man himself, somewhat sin)ilar mctaaiori.oses to ie place in intra-uterine life — the embryo having gills (not fully developed) before it has lungs, although as the blood, is not aerated within the embryo they can have no direct use. All Vertebrates are Quadrupeds, and each limb, if complete,, has five digits, but while in the Ungulata many have but two well developed digits to each limb, and in the Equine Family ali but one- have become atrophied, in the Order Ophidia, the limbs are com- pletely atrophied and functionless (with rare exceptions), and not apparent externally, that Order being in this as in the " vegetative repetition " of vertebrae, the most asymmetrical and specialized of the land Vertebrates, eo that the poison bag possessed by some of them,, was scarcely needed to make the ' ' Serpent " the fitting emblem of Evil in every Mythology. In accordance with the general law which I have indicated, this highly differentiated Type docs not appear among the early representatives of the Class, not having yet been found earlier than the Cretaceous Period. The remains of Fishes, the lowest and earliest, the most nume- rous and the most various or differentiated Class of Vertebrates, are found in rocks of the latest Silurian Epoch (and upwards), of two Orders, the Selachians or'Placoids, and the Ganoids. The first of these, of which the Port Jackson Shark is one of the best living, representatives, was approximately homoiogically * symmetrical,, had an internal cartiloginous skeleton, and was covered externally with shagreen or roughened skin, protected by a spine at each fin,, and had teeth consisting of broad bony plates, somewhat similar tO' those which formed a complete bony external skeleton in the only other then existing Order of Fishes — the Ganoids. These last were less svmmetrical than the Selachians, and although at first the ♦ Man being taken as the type. * ROSS — ON EVOLUTION. internal skeleton was cartalaginous, yet afterwards in the Devonian the Coccosteus, has the internal skeleton osseous in the jaws and vertebra}, and afterwards other families have internal skeletons still more ossified. The Coccosteiis and Pterichthys Families are re- markable as being the first examples of asymmetry, by the limb^ being ftmctionless, the former having no apparent fore limbs, and the latter no hind ones. The Teliosts, or Fishes with true bony skeletons and covered with scales externally, appear for the first time in the Cretaceous Period, and are the predominant Type among living Fishes. Some existing Families ha»'e no functional limbs, while others are dictorted in the most remarkable manner. Thus the Flounder, as also the Plaice, Halibut, &c., " is twisted half around and laid on its side. The tail too is horizontal. Half the features of its head are twisted to one side, and the other half to the other, while its very mouth is in keeping with its squint evcG. One jaw is straight and the other like a bow, and while one contains from four to six teeth, the other contains from thirty to thirty-five." It is interesting to note the development of true teeth among the oldest, so far as is known, of Vertebrates— the Skarks, for while the earliest had pavement teeth— broad plates like the dermal plates of their contemporaries the Ganoids, other Families of Sharks in the Carboniferous had narrower and sharper teeth, while in some exist- ing Families they are quite sharp. In the Ganoids the dermal plates vary much in character and disposition. Some of them had pave- ment teeth. The Sturgeon, an existing Ganoid, has no teeth. Most Ganoids since about the close of the Paleozoic Period, have shortened and bilobed or hetrocercal tails when mature, but when young have homocercal tails, like the ancient Ganoids. The Ptero- sauria, higher Batrachia, later Aves, higher Simiadce, and the Anthropidce, have the tail completely atrophied. The Teleosts deposit their spawn before fecundation takes place, while the Shark is in fact placental, bringing forth its young in a well advanced condition. Other existing Orders, of which however there are but few living representatives, show how exceedingly varied and wide in its limils is the organization of Fishes, for while the ''Mud Fish" has a heart with two auricles, external rudimentary branchiae, internal functional branchiae, and true hings, being thus R038 — ON EVOLUTION. much above the ordinary level of Fishes, the Amphioxus lanceolatua has no heart but only contractile arteries, no kidneys, a sac like liver, no vertebral arches, no distinct brain, no auditory organs, neither a cartilaginous nor an osseous skull, nor a mandible, nor any limbs, and even the Order represented among living Fishes by the Lampreya and Hags, though much more highly organized than tlie last men- tioned, seem devoid of any indurated tissue. And here I would remark the great imperfection of the Geological Record, since generally speaking only highly indurated tissue could be preserved, and thus whole Orders, even, of Cartilaginous Fishes have probably perished, leaving no fossil trace, and if they should happen to have no living representatives, as is known to be the case with some Orders among the lleptilians, then no definite record of their existence may now remain. And if whole Orders have no fossil representative, because devoid of well indurated tissue is it not probable that the earliest representatives of so. e existing Orders may have left no remains, especially as we have seen that the earliest fishes were devoid of any internal indurated tissue, and in the c -se of one of the earliest known Orders the Selachians, there was not n.uch well indurated tissue in the exo-skeleton ; so that it is proba- ble that it will ever remain impossible to trace back the various Orders of Fishes until they approximate so closely as do the earliest kno.wn representatives of the Saiiropsidia or the Mammalia. The Labijrinthodontia, an Order of extinct Amphibians which flourished abundantly throughout the Carboniferous Period, combine characteristics of existing Orders of Amphibians with those of the early Ganoids, while the Ichfhyosauria, the Plesiosauria, the Pterosauria, and the Dinosauria, are extinct Orders of Reptilians, which connect together the various Orders of existing Reptiles, and these again with Amphibians on the one side and birds on the other, so that all non-Mammalian Vertebrates are thus connected, and considering how imperfect the Geological Record as now known is, not only from its necessary imperfection, but also fron^ the limited character of explorations yet made, enough is known to suggest, if not to warrant, the opinion that originally the differ- ences were only " Generic" or even '* Specific" in value. The interval which separates the non-Mammalian Vertebrates 6 ROSS — ON EVOLUTIOX. from (lie Mammalia as found on tho great Continents, that u Asia, Europe and Africa, is wide indeed, for of the three Sub-classes into which, from their structure the Mammnh'a are naturally divided, only one —the farthest removed— is found there, the Monoddphia or true Maiamalia. OF the two remaining Sul-clispep Dlddphia or Marsupiallay and OmitkodclpJiia ; the first, though once abundantly represented on each of the Continents, is now nearly extinct in America, and is foimd abundantly represented only in Australia, where its isolated position has protected it from the results which elsewhere have followed its contact with the more difFcrcntiatcd and with the more highly organized tribes of the greater Continents ; and it is here also that the surviving represen- tatives—the Ornithorhyncus and the Echidna — of the Ornitho- delphia are found. If the interval separating the Marsupialia from the Sa^iropsidia seems insufficiently bridged by the two Genera, only, which arc known of a single Order, the Monotremata, the only surviving Order of the Sub-class Ornithodelphia, it should be remembered that every principle of analogy would lead us to anticipate, that when that Island Continent shall have been well explored n^eolo«i-i- cally, the remains of other Genera, Families, and even Orders will, as in the case of the Ganoidia and Lalyrinthcdontia among the Ichthyopsidia, restore to us the connecting links which in Mcsozoic Periods ga\e an easy transition from the Sauropsidia to the Mammalia. Of MoUusca^ the Tetrabranchiate Cephalopods, of which the Genus JVantihis is the only living representative, possesses some points of very special interest, as having chambered shells and continually moving outward as they grow, the shells, which have also the very great advantage of being exceedingly well preserved as fossils, present an epitome, perfect, so far as it goes, of the entire life of the individual ; so that there exists a singularly well preserved representation of the entire Order, — from its apparent origin in the Lower Silurian to the present day, when ii has almost become extinct, — alike ae regards the successive Species and the successive phases in the development of the individual of each Species, Ovthoceras^ of the lowest Silurian Enoch; the earliest j^mmmm lSI.'I, lipsfr ROSS — ON EVOLUTION. i nnd simplest known type, hud a shell in shape a straight cone, and had sirnide concave seota. It \^a8 followed by sucli forms as CyHoceras a-d Phrar/moceras, with shells resembling a bent cone, and with septa havinrr shallow lateral lobes. After these c.mrs Gyrocevxs, in which the bending of the shell has so much increased as to give it the form of a loose coil, and in which the lobes have become deeper, followed by others in which the coil bus become close, and the latter lobes more angular, until the shell has become involute and the umbilicus hrts been obliterated, as in Nautilus ziczac, of the Tortiaiy, and the living representatives of the Family. The Ammonite scric:, ui 'vhich a similar succession of forms occur, are remarkable for complication of their septa and the profu- sion of their ornamentat- n at the time of the Jurassic Period, when they had the greatest nun.ber of Specific forms. But this is true only of the adult individ^ial, for the earlier stages of the ufo of the individual represented accurately in a modified foi .1, the earliest Species ot the Series to which it belonged taking on successively the characteristics of the successive Species of such series until it arrived at maturity ; in the keeled group changing from four rounded to eighteen foliated lobes, and in form from an open coil to a com- pletely covered umbilicus, while in regard to ornament it takes on the characteristics of the Series to which it belongs in regular suc- cession during the succesaive stages of its growrh : *' In other words I'-iere is an unceasing concentration of the adult characteristics of lower Species in the young of higher Species, and a consequent displacement of other embryonic f-.atures which bad themselves^ also, previously belonged to the adult periods of still lower forms." While the shell-covered Tetrabranchiates, have long been continually decreasing in numbers, in specific forms, in size and in ornamenta- tion, the naked Dibranchiates, rival in size the largest of the extinct Tetrabranchiates, or the largest existing Fishes or Reptilians. Many existing Dibranchiates (such as the Cuttle fishes and Squids) have an internal skeleton or osselet, either calcareous, horny or mem- branous. The Connularia, fossil ossclets, which occur from the Trenton Epoch (of the Lower Silurian) to the Liassic Epoch (of the Jurassic Period,) irclusive, are still abundant and are renre- K0S8--ON EVOLUTION. acnted at present by such huge forms ,s MegaloUutUs harve,,i e oldest re.«a,„s of the Dibranohiates ; but since only the osseS z e^rsiiisir fr "■'/'' "-= ^-■■^"^" '^-'•^o'-p-'''- ^ fue earhet Fishes had no indurated internal skeleton, (and we know hat in the Calainaries it is often not calcareous and tl^a he Octo^,fe are destitute of it, the shell being represented by ZZi ''T' "'''"'' """'■''^ '" •'"^ eubsiancc oTt I nian le), they may have existed abundantly without havin^ left nnv defin, e traces. It is for a similar realon, doubtlel tha Z Ascidians though their structure would seem 'to indica 't tht hadavory remote origin, have never been recognised as fos^lT In^'' ---cident buriied their remains in.strata yf such a character as would preserve sand that woulu be preserved of the marine Species. It m„„ also habitat and numbers. Doubtless s'-nilar reasons account for the comparative scarcitv of fo»«il r„n. -ir. ~r n ' ■ — I. ...ii...m., ..r "-..^mrMijiaHa, known to have existed throughout the Tertiary and Po8t-Tert ir.ry, and of ROSS — ON EVOLUTIOiV. harveyif 3 osselets )cls, like (and we and tliat mted by ) of the left any that the lat they fossils. *eriod — to have internal of any naked, )r plate ! forms atisfac- Fishes far ay , have sidians e well trical) of the , until y and ic last cident ^serve thou- t also as to T the i^n to ad of Man, known to have existed in Britain before the last Glacial Epoch there, and in France during the Epoch characterized by the existence o: the cave bear. It should be well understood that Man differs physically in no way from the other Mammals, except ihat he is more advanced and is the central and only completely sym- metrical existing type. With regard to the other Orders of Mollusks, I will only remark that all t.ie marine tvpes aie, at an early period of their development, free swimmers and possessed of functional eyes, although many afterward become sessile, and many blind before they reach maturity. And if the land Species do r>ot so apparently exhibit this phase of development, it is because they pass through the corresponding transformations before leaving the egg. The Pieropoda which swarm about the great banks of floating seaweed of the mid- Atlantic, and form in the open seas of the Xortli the food of the Whalebone Whale, represent (approximately) in their adult form the free swimming stage of the Gasteropoda. The Tunicata (Ascidians) perhaps the most synthetic type known to us among the Mollusca, are remarkable as containing the proximate principle, cellulose, the basis o^ vegetable structures, and also as being, perhaps, the highest type of animal life in which individuals are reproduced by budding, so characteristic of the Radiates, both animal and vegetable. They have also peculiarities of structure which ally them with Amphioxus lanceolatus, the lowest known Vertebrate. The lowest known Genera of the Tunicata are the Append icularia,_ resembling a tadpole externally, and swimming freely by means of the tail. These when mature represent the immature ^orms of the higher Tunicata, before they become fixed or attached to rocks and their tails are absorbed : thus shewing the same tendency to shortening of the caudal extremity which 1"^ found in the higher and later representatives of almost every organic type. The Ajipendicularia then at the base of the Tunicata, are perhaps the most synthethic of organic types having structural peculiarities which ally them to tho Vertebrata, the Molhisca, the Articulata, and the liadiata, through the lowest types of ep.ch of these respectively. 10 KOSS— Ox\ EVOLUTION. The common ^nt, after rmnhi* ^i,^ *t, 1. , . ' ^^ leacMhi^' the three staffes sucpp^^^'vpI^ .n wh.cl. u .ep..e„.s the ,l„.ec classes of ArH^^aZZtl' Mcea,.nd I.secta-ioscs its >ving, before it begins to find food for .tsolf or for the eo„„„„nity. To what purpos^ tL„ does Ind"d „;:r tL^Lr::!;™;"'^- "" '-'- '-'"=- "■■'«' ••» e.pe„dit„re^of ;it. L::L::Lr:?he7od:^^r^^ i::: :i "«s los, nerve. &e., necessar, to use theL. but also exposedlol' the hn.ersofbeeo,„i„g the pre.y of inseetivorous crca Z ^^ni on the „,,g and after,vnrds, befo.re being cared for bT h p re Winds, &c ? To what purpose unless it be merely beeause it I™T :• ," '■' """^^ "« '>^»" -"!■''- except ;ou.h ho.,e phases wh.ch characterized the adult condition of'its pre fe- c ssors, just as all Vertebrates are furnished atone time in he^r d velopment w.th gills, though at the present day only he "owe Classes have any use for then,, and manv of the Amnh bia onlv before reaching the adult state. In suec'eeding Specie of In^ the w,ngs may become embryonic and functionlels. ' Jn the Eadiata, the planula (cs") of the Pnlvr. (I,„ T n c i. and the ^fn- c.i / . ^ '""'"' ™e 1 oiyp, the Jelly-fish, ad the ,>tar-f!sh, (representmg the three chief divisions) are quite whde a star-fish passes through stages in which it resembles fir^ the polyp and then the jelly-fish. dern~'th! p"" 'T'\ '™™ -P-™'»«iv- of the Echino- derms ucre he Crmo.ds, whose remains arc found abundantly in very formation fi-om the Lower Silurian to the pi-escnt day, wh „ they are represented by such Gener:. as PentacLs. All e.iltl" Eehinoderms pass through a Crinoid stage, and the higher nd atcr Families pass thi-ongh grades, representing the lower and older successively until they attain their own proper gi-ade at Tatut^ty «-l.en reproduction by the p,.„duction of pLuL occurs. irS CTn ' rf'/*"""" "P"""""S — -e crinoid Genera lead! The mode in which most individuals of this Class are produced, I ,,#' R03S — ON EVOLUTION. 11 Jcessively, - Vermes, 18 to find then does I it sports dried up from the ^ings and sed to all 'es while le parent ^ by the cause it tlirough s prede- in their B lowest 3ia only of Ants lly-fish, 'e quite I polyp, les first Schino- ntly in J when ^xistins: icr and d older iturity, Penta- stages, I lead- Juced, not by direct development from the egg, but by budding from other individuals, so that a whole community has its origin in a single egg, shews that in this as in some other respects the Radiata have structural peculiarities akin to Plants. It is perhaps worthy of remark that in Madrepores tht iop animal is always larger than the side animals, whether in the stem or the branches, as are the buds of a tree, the buds in either case being most vigorous in the most direct line, or in other words, less vigorous in direct proportion to the numuer of differentiations from tke direct line oj the original polyp. At the base of the lower Silurian, the Cephalopods, Articulates, and Radiates, disappear together, and save a few Fucoids a little lower, no well ascertained organic remains have been found in examinin"- the rocks downwards tlirough several miles in thickness. It was for this reason that Hugh Miller perceiving that the lines of organization (id may use the expression) approximate as we trace them downwards in the rocks — backwards in time — speaks of the life of the past as suggesting the idea of an inverted truncated cone. Dana estimates the maximum thickness of the Tertiary rocks at two miles, the Mesozoic at two miles, the Carboniferous at two two-thirds miles, tlie Devonian at two two-thirds miles, and the Silurian at four miles — thirteen and one-third miles in all. Accord- ing to Sir Wm. Logan the Cambrian and Laurentian Formations have in Canada a thickness of about seven one-half miles, and it is at the base of these that Eozoon (so called) has been found, forming a fitting apex to the cone. Tb'' Protozoa, at the base at once of the animal and vegetable Kingdom",, are found, if Eozoon canadense and Eozoon bavaricum arc really of organic origin, as claimed by Dr. Dawson and others, far below, that is, of an earlier period, than any other well recog- nized organic remains. Most of the existing Protozoans are microscopic. They have ^cn classified as Plant-like, Radiate-like, Mollusk-like, and Articulate-like; a classification which indicate plainly in these — which it can scarcely be doubted are representative of the earlier organisms in the same sense that the Fishes of the present day are representative of the earlier Fishes, that is diflferen- 12 ROSS — ON EVOLUTION. tinted asymmetrical modifications of the earlier fvnn. *u .-. .cndonc, to .l.e ..iffere„tia,i„„, .^ll ^trnX^^J TT great groups of organic structure next above I P,"^ , .n rank an. i„ the period of their devlptent. """'"' "'"^ uniil if fn^ fi V iP -^"'Jp, navmg like locomotive powers once classed with thp P.... ^ ^ ^^''"' *^''** ^^re ^xc..»Lu wirn ttie l-'roiozoa, are now known +« k i , mere embryonic forms of the !<, v^st Plait, Tr ! "'^ "" . -^y I^'^ a"^ of the hicrher Articulates as Worms The simpler Protozoans seen) to consist of a sinc^le Slln f A. • • . "'"o'e egg) ni the earliest stan-e of tlw r,^r. As we nse m the scale of animal life or »« „, f i? ,. ^^' sion of fossils upwards in the f, ' °'' ""^ '"'"'^'- find in each a corresponding locali.^Tion o , f ""?'*^ "'' specialisation of tisstfe. It is r t, t in c ' ? '"'""'''^ it is nceessarv tn n t , " "omparmg the first two animals reo'n.r::ith"t/ r'";""'""^"'"" "^ "■<= '»'« ROSS— ON EVOLUTION. 18 lere exists led in the zoa^ alike (seeda or ; freely by itself i{) a no longer V. Very e powers ;he power that were only the ■ Artie u- ive been or of an iation of I though irbonate first of s exists inity of lumbers le cgQ. succes- ow the lis) we uitable St two e later same ing 80 Y way others armor e any I « I functional organization for reproduction. But allowing for all these the analogy seems perfect. Dana estimates the comparative Juration of the Post Tertiary, Tertiary, Mesozoic, and Palaeozoic Periods, as approximately expressed by the numbers 1, 2, 4, 14, respectively. Sir Wm. Loiran's estimate of the thickness of the Cambrian and Laurentian rocks of Canada, be taken as the maximum thickness of these, it is probable that they represent a period equal in duration to the Palaeozoic Period. So that the various fossiliferous rocks may be estimated to have occupied a Period equal to thirty-five times that of the Post Tertiary, which was probably not less than half a million years, so that for the accumulation of the twenty-one miles in the thickness of the various Zoic Formations, it will be safe to estimate the minimum duration at fifteen millions of years, though it may have greatly exceeded even this immense Period. But was the Epoch o{ Eozoon^ indeed that of the " dawn " of life? and are we to consider this large and very complex community of animals as the primordial type ? or should we not look rather for a series of types of increasingly complex, and numerous commu- nities of Protozoans leading up to this ? and is it not probably that for no inconsiderable period previous to the existence of Eozoon Canadensis, Protozooa flourished in great numbers and of great size, the sole living occupants of the Earth? The obscurities of embryology may be enlightened wonderfully (though I do not remember ever to have seen it remarked) by studying carefully the embryology of that Class of each Sub-kingdom in which individuals of certain Orders change or partially change their habitat, during the free life of each, from water to land, since in those Orders in which the young are brought forth on land, they must have reached u very much more advanced stage before leaving the Qgg, than in those in which the young become free in the water ; and there is thus afforded admirable opportunity of comparing allied forms in the same stage of* development, in the one case within the egg, whether intra- or extra-uterine, and in the other while living an active free life in the water ; these last occupy- ing, from every point of view, an intermediate position between the first and the Species in the past history of the Earth in which the 14 ROSS— ON EVOLUTION. mature individuals, living- of conr^n ,•„ fi.« .ame stage of devclop^en" '" "'"'"' ''''"''""'^ "■' All existing Kadiatoa have ti.ese remarkatle peculiarities that thoy are all sessile at some stage of the lif- „( .1 „ .'""'' "'•" .hat„o„eoft,.e,„e.hihitn„,of\hat'!:ee;u r:':^^^^^^^^ only s;,„ple se„satio„_the eo™,„o„ basis of them ull. All Jiat that hve m the water, when they first leave the nlannla ITf swimmers, and all the higher Orders of them b om' Te a. il l" oontmue so during their .nature life. Land Plants , th^ llher 0.d rs, „,„e, re radiate in structure, and co^^peM, s le L hab t, seem almost destitute of sensation, and of the n„»^r If .not.on .n^.eir free e.tremit,, and also of the power di ^l on although I)ro.era and son.e other Genera exhibit all three ^1 .essde Orders of ^..,-o„toa and .MolluscoMa are rem t ble f .1.0 aet that as each individual reaches the sessile sta.e lost h ^.ght, and the tendency to Cep/^ali^aHon, whicht . „ k d aracter.st,c„fthe Orders of Animals, which preserv tl Totr of free mo ,on, and which progresses in each in time from he earhest period in which we can trace it as a distinct 0,7 K n^ans of its fi,ssi, remains, to the present day.^ 'C m^ ^. J by the .ncrcastng comparative size of the brain cavity, the le ntl and sometunes complete atrophy of the posterior extr mi y r t J alao by th3 concentration of the liu.bs around the anterior exttUiv and then- adaptability to serve its purposes. A shorten n'ofle jaws and mercase of the facial angle is also usually characto-ist c „f progress m t,me among higher Orders of .4„imais; and in Ma " as ri,::"Kar ' ' '- -^ °^ '- -^ ""^'^ i. tinctirs^rf-t,: -wn. with ^-y:^^.>:.z:i:::z'7:ri^^t^ EOSS — ON FVOLUTION. X5 resented the aritles, that vidua], and senses, but ^11 Radiates ila are free B again and the higher ' sessiJe in power of digestion, ii-ee. The irkable for t loses its 1 marked the power from the 3vder, by nanifested lessening Y or tail, extremity ig of the teristic of Man, as ns of the ilization. from the tig along nearly a iiderably till less, n wlien already te from homological symmetry as they approach maturity. Next to these come successively other groups of Monkeys of the great Continent, all of which have the same number of teeth as Man, and compara- tively narrow noses, hence called Catarrhines, while the Monkeys of America, except a peculiar group, have one tooth more, a grinder, on each side above and below, longer jaws and bioader noses, hence called Platyrhines. In Man only is the attitude entirely erect, the fore limbs being thoroughly adapted for use as prehensile organs, — instruments of Vv'onderful adaptability as minis- ters to his will. In these respects there is a corresponding gradation among the monkeys, the Catarrhines having the thumb opt.osable to the fingers, and the hand generally rather adapted for use as a hand than a foot, and many species are like man without a caudal appendage, while the Platyrhines have not the thumb opposable, but have long prehensile tails. Other groups of Monkeys are still more differentiated, and have been described as Squirrel-like or as Fox-like — these last being somewhat carnivorous in their habits. The remains of Monkeys have been found in the Eocene in America, and these arc found to be of less differentiated types than existing American Monkeys, and have characteristics which ally them to the existing forms of the next lower grades of the Mam- malia, the (Jarnivora and the Ungulata or Herhivora, and it is a curious and instructive fact that each of these Orders was at first, without exception, plantigrade, that is, walked on the entire foot as does man and do Monkeys, so that the later digitigrade types were reached in each case by a gradual differentiation. Xnsectivores, Rodents, and Marsupials present a similar series of types, the lower being plantigrade and the higher, and later, digitigrade. All the Edentata and Monotremata arc plantigrade. All the Mammalian remains of the Eocene are of highly generalized types. JDidelphia consists of Series differen-iated so similarly to those of Monodelphia as to have the same names applied to them, viz : Marsupial Monkeys, Carnivores, Herbivores, Insectivores, and Rodents. That Didelphia had at the time of its greatest expan- sion marine representatives, corresponding to Cetacea and Sirenia among the Monodclphia is altogether probable. A somewhat similar paiallelis:a exists between the various Orders of Reptiles 16 ROSS — ON EVOLUTION'. and An,phibi„„a Indeed as we trace each great group f„rwa„l, Jiom the general to the particular, or enecial f^„^ ,1. • . ""* for en,nnl„ t„ .1. , ' "' 'P'=<^'""> 'roiti the ominivorous lor example, to the more and more completely herbivorous carni vorous or msecfvorous, and from these to others havin, s, 'll mo „ .^eo,a/,Whab,ts as to food, and all the corresponding ,Tee2Z oforganization and instinct. 'ura„ pecul.anties Again there is the tendency outwanls as to habUat-to occupy 1 e ' Ead,:;' :: Vr^r^'^'^' -^ «--■ and that in eve^ Climate. ±.ach of these differentiate into rivino- anrJ nnn fl„' , :: Li r f r*' '"'° '"-'-- ^^::f::iz::' m fact each subordmate group as it expands has a tendency L; be more or less fundam'ental t:"lf::Z^ZrZ:Z he Ck^eroptera the adaptability for flight seems more fundamental than that for a particular variety of food, since some exist on "ml adap,abd.tyforfl,ghtseemsofamuch less fundamental character There seems to haye been a steady increase in the sile of he larger an.mals of each succeeding grade, correspond in , "the Shark of the Upper Sdurian to the hugh Cetaceans of the RecenI Per.od ; and on land from the Zub^rModonHa of the De™ an to the Kecent Mastodons. lU larger animals of each grade s, to have been exterminated by the larger animals of the succeedTn; bulk Th ""fT"'"' """"'^ ^'""S'h and ultimately even of bulk. Thus the .argest types of each grade, except the hi.he^t have been constantly and successively L „ mghest, extermlmfinn .„ .1, . snocessivUy m every sense undergoing extennmatton, so that, as we go down,vards in grade, we find the cxistmg representatives smaller until we reach fL P , , they are mostly Microscopic, altho.gl XV cb ^^w: i: maxmmm ,t had representatives comparable in size thour ,1 ,«..e e,ual, to the largest of the succeeding g^dr* Ks w have seen that directions taken by the different Order of each Grade, have been approximately parallel or similar, each to e ', 510SS — ON EVOLUTION. 17 ip forwards >n outward •minivorous '0U8, carni- ? still moic leculiaritiee -to occupy t in every ^ying, and )urrower8 ; ndency to tions, and tions may Thus in idamental on almost hecus the character, e size of ig to the ichian or e Kecent Devonian ide seem icceeding •r life in even of highest, [lergoing find the •a where was in Jgh aot r CIO liYU of each o each, and as the lower and earlier grade had begun to differentrnte soonest it is plain that only its more differentiated types would be well out of reach of this competition of the V.gher, and that thus the less differentiated types of the lower ..'ould be constantly and successively undergoing extermination, and thus only the most diifercLtiatcd types continue to exist, except when the more synthetic, types are preserved, by isolatio7i from the access of types of a hi-her -radc, or by a difficulty of access arising from any other cause The Great Continent, particularly the northern Grand Division of it, Asia-Europe, has been during the later Tertiary, the Post Tertiary and Recent Epochs the theatre par excell :-o of progress in every organic type, which is represented there. It was not always so, however for North America in the Eocene seems, both in re-ard to its Plants and Animals, to have reached a stage only reached in Europe and Asia in the Miocene, no doubt by a migra- tion thither of the Plants and Animals of North America, implying, of course, a continuity of the Continents at that time. But while North America has made little progress comparatively m the differentiation of its Plants since the Eocene, it has been far different on the Great Continent, which is consequently now far m advance ot North America, and though the differentiation of the higher Animals in North America has been much greater comparatively than o its Plants, yet in this r.spect also it is in every way inferior and behind the Great Continent. South America may be said to represent in a general way the Eocene of North America, and Australia the Cretaceous of North America and the Cretaceous and the Eocene of the Great Continent, while New Zealand with its -ncrantic birds as the highest type, represents an earlier Mesozoic Epoch, and the Gallapagos Islands with their gigantic Reptiles, probably represent a still earlier Epoch. In each of these cases the comparative cessation of progress referred to, seems to have been the result of isolation from the then Great Continents~the chief centre of pro^r-ess and of differentiation, or in other words, ot progress upwards and of progress outwards, -outwards, not only in space but in those adaptations which have given to each grea. group representatives suited for every possible mode of existence. 2 .M 18 ROSS — ON EVOLUTIOX. South America has more recently been again united to N'ortfi America, but climatic causes have prevented a rapid migration of jNorth American types. These are a few typical illustrations of a principle illustrated everywhere, since in fact every considerable Island or Archipclao-o dlastrates it, and even on the Continents, great mountain ran-el-, deserts, &c. serve as barriers to the migrations of land Species, and tlie C ontments themselves to those which inhabit the sea, while to those which inhabit the shallow waters, the ocean depths present a barrier hardly less impassable than to land Species. It must be remembered too that each great group has its own centres, and subordinate groups theirs .Iso, and that these all vary in position with the varying changes of climate, elevation, &c. As a sinn-le example of local centres for subordinate groups, the Humming-btrd may be given, of which more than a thousand Species inhabit bouth America, though none are known e; cr to have existed out ot America. Species of the same Family found in locolitics Ion- isolated from the chief existing centre of differentiation, for thai tamily are usually smaller, less vigorous, and less fully difFerenti- ate(i than the oJiers, resembling the immature forms of the more aifierentiated Species. A most interesting and suggestive fact in the distribution of •Urganic Types is the existence in Regions more or less recently isolated from each other, of representative Families, Sub-families, Genera, Sub-genera, Species, or Sub-species, according apparently to the length of time the isolation has existed, and to the rapidity with which differentiation takes place in the particular Group selected for comparison, and that in lands long isolated from ea.li other the Organic Types are very different, however similar may be the climatic and other conditions. In Europe and North America, which have probably been separate since the Miocene Epoch, many Genera exist having a certain number of Species in the one corras- pondmg to a certain number in the other, each to each. I quote from Prof. Wyville Thompson : - On either side of the Isthmus of Panama the Echinoderm order J^^chimdla, the sea- urchins are abundant ; but the species found on the two sides of the Isthmus are distinct, although they belong almost universally 1 . -^ -^ J10S3 — ON EVOLTjTION. 19 to North ^ration of llustrated chipclago 1 ranges, Species, lea, while 3 present must be tres, and position single ling-bird I inhabit isted out ics loiMZ for that ifFcrenti- he more ution of recently amilies, )arcntly rapidity Group m each may be inerica, , many corres- side of he sea- ides of ersallv 1 I to the same Genera, and in most cases each is represented by Species on each fide which resemble one another so closely in habit and appearance as to be at first sight hardly distinguishable, I arrange a few of the most marked of these from the Caribbean and Panami'' sides of the Isthmus in parallel Columns. EASTERN FAUNA. Cidaris annulata. Gray. Diadema antiUamm, Phil. Echinocidaris pun ctiilata , Desml. Echinometra michelini, Des. Echinometra vh'idis, A. Aa. Lytechinus variegatus, A. Ao. Tnpncustes ventricosus, Ag. Slolonoclypus ravenilr, A. Ag. MelUta testudinata, Kl. Mellita hexapora, A. Ag. Encope michilim, Ag. Encope emarginata, Ag. lihyncholampas caribhcsarum, A'. Ag. Si'issus coliimbaris, Ag. Meoma ventrosa, LiiTK. ZHagionotus pectoralis, Aa. Agassizia excentricia, A. Ag. Moera atroposy Micii. WESTERN FAUNA. Cidaris thouarisii, Val. Diadema mexicanum, A. Ag. Echinocidaris Stellala, Ag. Echinometra van hrunti, A. Ag. Echinometra rupicola, A. Ag. Lytechinus semitubercula^usy A. Ag. Tripneustesdepressus, A. Ag. Stolonoclypus rotundusy A. Ag. 3Mlita longifica, Mich. Mellita pacijica, Ver. Encope grandisf Ag. Encope micropora^ Ag. Rhyncholampas pacijicus, A. Ag. Brissus obems, Yer. Meoma grandis, Gray. Plagionotus nobilis, A. Ag. Agassizia scrobiculata, Val. Moera clothe, Mich. The Isthmus must have been raised into dry land in Tertiary c Post Tertiary times. It is difficult to doubt that the rising of this natural barrier isolated two portions of a shallow water fauna which have since slightly diverged under slightly different conditions. I qaote A. Ag. : "The question naturally arises, have we not in the different Faun« on both sides of the Isthmus, a St.. sdard by 20 ROSS — ON EVOLUTION. which to i:ien3urc changes which these species have unJergono since the raising of the Isthmus of Panama and the isolation oHhe two Fauurc?" But it is not only in distinct «« areas " that we find *' representa- tive "Groups, but they occur succ-ssivcly in the same area, since in successive 8tr^ca are found representative groups of Species, at wider intervals, of Genera, and at still wider of Families. It is interesting to note in this connection the gradual differentiation of a Sub-kingdom by the steady increase of iti Families, Genera, (&c., the expansion and differentiation cccuring in its central and charac^ teristic types, while those typos of a more intermediate, synthetic, or connective character, tend to become extinct unless saved by some exceptional circumstance, as isolation, &c. No Sub-kingdom has left so good a record of itself in the Rocks as the iMollusca, and according to Woodward the number of Jb amihes for the Formations is approximately as follows : Silurian 20, Devonian 21, Carboniferous 30, Triassic 35, Jurassic 41)- Cretaceous 5G, Tertiary G2. The Genera for the same Formations ui the same Order were 53, 77, 79, 81, 108, 148, and 192 respec- tively. The decrease of such Families as have become extinct, or seem in process of extinction, is a similarly gradual process, and occurs first m the Genera, least typical of the Family, o. most synthe- tic in type ; so that both increase and diminution seem to follow an organic law. which may be illustrated (though of course the analogy 18 far indeed from being perfect) by the growth of ?i branch of say a fir tree, and in the case of the Families which have become extinct the gradual withering and successive death of the branchlets, untd finally tho toprost bud, and with it of course, the branches succumbed to -ne crowding and pressure of the superior and sur- rounding branches. Of course the regularity of this process in the family is interrupted by the fact that in isolated areas the older types may be preserved and even extended. Another aifficulty in defining the limits of Species arisics from the fact of the intercrossing of Species of the same Genus, and although the product is usually eterilc except with cither of th^^ original Species, yet the incorporation by this means of an element Irorii one Species into another, seems incompatible with the idea of ,1083— ON EVOLUTION. ^1 e unJergonf lation of the ' * reprcsenta- i area, since ^ Species, at lilies. It is rcntiation of jrenera, <&c., and charac- e, synthetic, 88 saved by in the Rocks number of I : Silurian urassic 41); Pormations 192 respec- extinct, or )roces3, and nost synthe- ;o follow an the analogy inch of say ve become branchlets, le branches T and sur- cess in the J the older iriiics from jrenus, and hcf of th° m element the idea of the two Species having been originally distinct and without any .rencric affinUy ; but tho difiiculty of entertaining such a supposition becomes still more striking when the product of such intercrossing of Species is fertile inter se, as in a case described by the ate 1 rot. Acrassiz. and where it is evident that the new Species (shall I say si;:ce there is no other possible way of classifying it) might continue to exist, in its entirely distinct form, throughout a (leologica Lpoch, if brought to a Soutn Pacific Island, where it would be alike free from competition and from admixture with allied Species ; indeed m the case referred to below it seem. Tkely to be continued as such m a domestic condition for economic reasr ^s. Aga^siz says : - There are, however, two animals entirely distinct a. to specific characters -the hare and the rabbit of Europe ; (I do not speak of those of the United States, respecting which such observations have not yet been made) : the»c animals have been crosseu and oflPspring has proved to be fert.:e, not only with the original Species, the hare nnd the rabbit, but the cross br-^ods themselves, the individual derived from the crossing of hare and rabbit have been fertile amon- themselves. Thu3 a new breed, which thus fai exists only in domesticity, has benn produced and is known under the name of lep ride in the Paris market, where it is as common now as tfie hare or rabbit. This new breed differs in ti.c colour of the flesh from both hare and labbit, the ^ormer being dark the latter white, while the leporide has an intermediate condition of meat much esteemed for its flavor and delicacy." The total number of known distinct existing Species (so called) of Animal« and Plants is about half a million. Of these it may be said that the higher the grade to which they belong, anc the hi-her the group within that grade, the shorter lived or less persistent is the Species, ana the wider the limits of its variation, so much 80 that in the case of man^ it is difficult or tmpossible to decide as to the limits of each. Indeed every attempt to define absolutely what constitutes a Specific, distinction, has resulted m failure, and we are left to accept ihe opinio^, of Agassiz tha a Species is an ideal - entity,' in no way diflfhrent in kind but only in degree, from Genera, Family, Order, &-:. A hundred illustra- tions night be given of the difficulty, or rather the imiio38ibility oi ■^ M 22 KOSS — ON EVOLUTION. determining absolutely whether certain groups should be considered as constituting a Genera consisting of a number of Species, or a .bpecies consisting of a number of Varieties. I avail myself of the case ofliubus, so well elaborated by Prof. Lawson, and doubtless fresli m the recollection of members. (See Trans, pages 364-6.) - Ihis IS particularly the case with regard to the European Hubt fndicost many of the long recognised species of which are so closely related, that some of our best botanists now rank upwards of twenty forms that are too well marked r.nd too constant to be mere varieties, as so many sub-species under the specific type of linbus fniticosus" ^ In estimating then the total number of existing Species, the impossibility of defining the limits of each Species is in itself an insupemble barrier to complete success. It must also be remem- bered that while the land surface of the Earth, and the shallow seas are far from having been corr.pletely explored, the Jeep sea forms are almost unknown, although the researches of the " Challen-er" Expedition has shewn that they are abundant, and as the nature of their habitat must effectually prevent the rapid ingress of later, more highly differentiated, and more typical forms, that is, forms typical of a larger group, they will be found to be more synthetic and antique in their more general characteristics, such as those pertaining to Order and Family, but at the same time more differ- entiated m their more specific characteristics, such as those pertain- ing to Genera and Species, as was found to be the case with those already discovered. The wonderful development of the organs of vision of the more predatory and active Types and their atrophy in tie case of theothers, is a striking illustration of the possibilities of difFerentiation in adaptation to circumstances, though paralleled by he differentiation of the imperfectly ighted types of earlier times nto the (usually) better sighted, higher, and more active Types of the present day on the one hand, and into the cightloss sessile Types on the other. Any attempt to estimate the numbers of extinct ^pecies must necessarily be very vague from the necessary imper- fection of the Geological Record, as well as our as yet Lperfect acquaintance with it ; bt.t enough is known to make it certain that the extinct Species were many times more numerous than those ROSS — ON EVOLUTION. 23 be considered Species, or a myself of the ind doubtless Lges 364-6.) ropean Hubi rhich are so link upwards nstant to be cific type of Species, the I in itself an ) be remem- shallow seas p sea forms 3hal]enfjer " be nature of ss of later, •.\t is, forms e synthetic, ih. as those nore differ- 3se pertain- with those e organs of atrophy in isibilities of tralleled by rlier times e Types of ssile Types of extinct ny imper- imperfect 3rtain that than those now existing, so that it is clear that many millions of Species have been created, during a period of millions of years ; and this was all accomplished in the most gradual and systematic manner possible, both as to creation and extinction ; the apparent exceptions occurring in exceptional circumstances, and themselves conforming to their appropriate laws, and being therefore of that kind which have been said to " prove the rule." It is not therefore surprising that while all, who have any considerable knowledge of the subject, are Evolu- tionists in the sense of comprehending that creation of the successive types exhibit the gradual evolution or unfolding of certain ideas, a very large majority of the leading Men of Science of the present dav believe that the Creator formed the various Species, so called, by the operation of His Laws from a single protoplasmic prim- ordial Type, rather than by a direct, miraculous (in the ordinary sense of that word) creation of, as I have said^^many millions of Species spx-ead over many millions of years, and governed in the minutest particular by laws involving complications, a few of which I attempted to indicate. It is perhaps worthy of remark that if Species were created by an immediate act instead of by a continuous process, and each put into a particular spot of the land or water, which was to become its home, they must, unless created in consid- oraMe numbers, have been miraculously preserved also, inasnuich as otherwise, in many cases, they would be sure to be exterminated » almost immediately. Again, a belief in the miraculous creation of each Species almost necessarily leads to a belief in the creation of representatives of it in distinct and often widely distant centres, as was held by the late Prcf. Agassiz, and also to this difficulty, that since the various Eaces of Mankind, exhibit differences equal to and even greater than those which are considered Specific in the lower animals, we are driven to the conclusion, which was reached by Agassiz, viz. : that Man consists of distinct Species and may have had many while he must have had several distinct centres of creation. I quote the words of Agassiz : "Now, then, what do we find among men? Similar difierences again. For men have not all the same complexion, nor do they all exhibit the same characteri8tic features. And here let me urge upon you this fact, for we cannot cont^idcr the relations of mankind to monkevs unless 24 ROSS — ON EVOLUTION. we are aware how v.Idely men differ from one another. Wliilc tliey have all the characteristics of human* there are yet among them differences about as striking as the a. ..-ences which distin- guish some of these geaera of monkeys from one another— as striking I. questionably as the differences of some of the species of monkeys from one another. And I am bound to say that unless we recognize the differences up-.ong men, and we recognize the identity of these differences with the differences which exist amon- animals, we ar^ not true to our subject. And whatever be the origm of these differences, they are of some account, and if it ever ]s proved that all men have a common origin, then it will be at the same time proved that all monkeys have a common origin, and it will by the same evidence be proved that men and monkeys cannot have a different origin. This is the appalling feature of the subject —that the characteristices which distinguish the different races of men are of the same nature as the characteristics which distinguish the different kinds of monkeys. And it was for that reason" that early I maintained that the different races of men must have had an independent origin, because I saw the time comin- when the question of the origin of man would be mixed up with tlic question of the origin of animals, and a community of orio-in mioht be affirmed for all. Now, I hold that the idea of the community of ^ origin of man and monkeys and the other quadrupeds is a flillacy, the foundation of which I shall try to explain p:.escntly. But if it 18 error to consider man as derived from monkeys, we must admit that men are not derived from a common stock, because the differ- ences which exist among men are of the same kind and quite as striking as the differences which exist bet^vecn monkeys, and between tiie lower animals." Now, I need not say that a disbelief of the original unity of Man IS irreconcileable with Christianity, so that if as A-assiz afhrms, a common origin for the liaces of Mankind necessarily implies a common origin for the various Species of each Genera of Monkeys, and for each of these Genera and Man, then, from a theological point of view, we would be driven to accept the view which assigns a common origin to Man and the Monkeys, and if to these then to till fh^. Vp*^*"b)- * - a,, l i- ■^ ^ \^ ...I .... > CvOKuvc, ana uiumaiely to all organic R0S8 ON EVOLUTION. 25 •thcr. Wliilc re yet among which distin- ! another — as he species of Y that unless recognize the exist amonjr tevcr be the nd if it ever ^'ill be at the )rigin, and it ikcys cannot >f the subject ent races of I distinguish reason that have had an g when the :hc question a might, be nmumity of s a fallacy, But if it must admit the diifer- tid quite as nkeys, and ginal unity as Agassiz necessarily Genera of en, from a t the view !ys, and if ull organic I ha^'e thus endeavored, in intervals snatched from professional study and daily avocations, to sketch in ..utline this great subject, in undoubting faith that fidelity to truth is the only true fidelity to Religicm and to God. When Man began to arm himself with weapons against the •Treater Animals within his reach, these had reached their maximum, and began to be speedily exterminated before his attacks, for while in the earlier Post Tertiary the greater Continent and North America were the homes of the greatest Megasthenes (or higher Vertebrates) that ever lived, almost equally great Edentates flour- ished in South America, and similarly vast Marsupials in Australia, while Cetaceaans probably the largest, without exception, of animals that ever lived, flourished in the Polar Seas. OF all these most of the largest have perished already, while as Man improves his arms and adds to his intelligence, the greater animals which he refuses to take under his protection are rapidly disappearing before him. The process of extinction, therefore, has been proceeding during the Recent or Human Epoch with a constantly accelerating and unparalleled rapidity. But while Man is rapidly exterminating most Species which ar?. within his reach, and which he does not choose to protect, the number which he takes under his protection is continually increasing, and it so happens (though of course there ie no chance in the matter) that the opecies, which for economic purposes he takes under his protection, are precisely iiw^Q which are the repr Tentative types of the Families or great GroujjS to which they belong,— the topmost buds of the greater t)ranches of the tree of life. They are thus the natural centres of differentiation, possessing at once the greatest vital power and the greatest possi- bilities of viM-iation, hence also of cultivation and of naturalization 1»£ every part of the Earth, — })rocesses which I need not say are being accelerated yearly, almost daily, with the increasing facilities for locomotion which are so characteristic of the current century, — processes which have already afforded results the most invaluable to Mankind, and promihc incalculable advantages in the futui-e. But it is in Man, himself, the representative of the entire Group of organic Types, — the topmost "upright" stem of the Tree of Life, that all the possibililies of differentiation and of culture cul- 26 ROSS ON EVOLUTION. lilli > I it I lit . s minate, and I do not therefore share the gloomy anticipation of Prof. Dawson, that there will " enfiue a period of decadence until it (the human race) becomes extinct," but believe that in Man as in the lower Animals, while the inferior and more synthetic types will be successively exterminated, the higher and more differentiated types will be continually expanding, and that the *' meek sha" inherit the Earth," and rejoice in the life that now is and tl assurance of that which is to come, by faith in Him, who is the Way and the Life — the Son of Man and the Son of GOD. I ifition of nee until Ian as in f'pes will rentiated ;ek sha" and tl • 10 is the I