194 



SCIENCE. 



IVoL. II., No. 28. 



of the adjustments involved in aucli a supposition. 

 How superior tbey must be to our rude and alwaj'S 

 more or less unsuccessful attempts to produce and 

 carry forward varieties and races in definite direc- 

 tions! This cannot be chance. If it exists, it must 

 depend on plans deeply laid in the nature of things, 

 else it would be most monstrous magic and causeless 

 miracle. Still more certain is this conclusion when 

 we consider the vast and orderly succession made 

 known to us by geology, and which must have been 

 regulated by iixed laws, only a few of which are as 

 yet known to us. 



Beyond these genei-al considerations, we have others 

 of a more special character, based on paleontological 

 facts, which show how imperfect are our attempts, as 

 yet, to reach the true causes of the introduction of 

 genera and species. 



One is the remarkable fixity of the leading types of 

 living beings in geological time. If instead of fram- 

 ing, like Haeckel, fanciful phylogenies, we take the 

 trouble, with Barrande and Gaudry, to trace the forms 

 of life throu^li the period of their existence, each 

 along its own line, we shall be greatly struck with 

 this, and especially with the continuous existence of 

 many low types of life through vicissitudes of physi- 

 cal conditions of the most stupendous character, and 

 over a lapse of time scarcely conceivable. What is 

 still more remarkable is, that this holds in groups 

 which, within certain limits, are perhaps the most 

 variable of all. In the present world no creatures 

 are individually more variable than the protozoa; as, 

 for example, the foraminifera and the sponges. Yet 

 these groups are fundamentally the same, from the 

 beginning of the palaeozoic until now; and modern 

 species seem scarcely at all to differ from specimens 

 procured from rocks at least half-way back to tlie 

 beginning of our geological record. If we suppose 

 that the ijresent sponges and foraminifera are the 

 descendants of those of the Silurian period, we can 

 affirm, that, in all that vast lapse of time, they have, 

 on the whole, made little greater change than that 

 wliicli may be observed in variable forms at present. 

 The same remark applies to other low animal forms. 

 In forms somewhat higher and less vai'iable, this is 

 equally noteworthy. The pattern of the venation of 

 tlie wings of cockroaches, and the structure and form 

 of land-snails, gally-worms, and decapod crustaceans, 

 were all settled in the carboniferous age in a way that 

 still remains. So were the foliage and the fructifica- 

 tion of club-mosses and ferns. If at any time mem- 

 bers of these groups branched off, so as to lay the 

 foundation of new species, this must have been a 

 very rare and exceptional occurrence, and one de- 

 manding even some suspension of the ordinary laws 

 of nature. 



Certain recent utterances of eminent scientific raeiv 

 in England and France are most instructive with 

 reference to tlie difficulties which encompass this 

 subject. Huxley, at present the leader of English 

 evolutionists, in liis ' Rede lecture ' i delivered at 

 Cambridge, England, holds that there are only two 

 ' possible alternative hypotheses' as to the origin of 

 ^ Report ill Nitlure, Juue 21, corrected by tlie author. 



species, — (1) that of 'construction,' or the mechan- 

 ical putting- together of the materials and parts of 

 each new species separately; and (2) that of 'evolu- 

 tion,' or that one form of life 'proceeded from an- 

 other' by the ' establishment of small successive 

 differences.' After comparing these modes, much 

 to the disadvantage of the first, he concludes with 

 the statement that " this was liis case for evolution, 

 which he rested wholly on arguments of the kind lie 

 had adduced;" these arguments being the thrend- 

 bare false analogy of ordinary reproduction and the 

 transformation of species, and the mere succession of 

 forms more or less similar in geological time, neither 

 of them having any bearing whatever on the origin 

 of any species or on the cause of the observed suc- 

 cession. With reference to the two alternatives, while 

 it is true that no certain evidence has yet been ob- 

 tained — either by experiment, observation, or sound 

 induction — as to the mode of origin of any species, 

 enough is known to show that there are numerous 

 possible methods, grouped usually under the heads 

 of absolute creation, mediate creation, critical evolu- 

 tion, and gradual evolution. It is also true that 

 almost the only thing we certaitily know in the mat- 

 ter, is that the differences characteristic of classes, 

 orders, genera, and species, must have arisen, not in 

 one or two, but in many ways. An instructive com- 

 mentary on the capacity of our age to deal with these 

 great questions is afforded by the fact that this little 

 piece of clever mental gymnastic should have been 

 practised in a university lecture and iu presence of 

 an educated audience. It is also deserving of notice, 

 that, though the lecturer takes the development of 

 tlie Nautili and their allies as his principal illustra- 

 tion, he evidently attaches no weiglit to the argument 

 in the opposite sense deduced by Barrande — the man 

 of all others most profoundly acquainted with these 

 animals — from the paleozoic cephalopods. 



Another example is afforded by a lecture recently 

 delivered at the Royal institution in London by Pro- 

 fessor Flower.^ The subject is, ' 'I'he whales, patt 

 and present, and their probable origin.' The latter 

 point, as is well known, Gaudry had candidly given 

 up. "We have questioned," he' says, "these strange 

 and gigantic sovereigns of the tertiary oceans as to 

 their ancestors, — tliey leave us without reply." 

 Flower is bold enough to face this problem ; and he 

 does so in a fair and vigorous way, though limit- 

 ing himself to the supposition of slow and gradual 

 change. He gives up at once, as every anatomist 

 must, tlie idea of an origin from fishes or reptiles. 

 He thinks the ancestors of the whales must have 

 been quadrupedal mammals. He is obliged for good 

 reasons to reject the seals and the otters, and turns 

 to the ungulates, though here, also, the difficulties are 

 formidable. Finally he has recourse to an imaginary 

 ancestor, supposed to liave haunted marshes and riv- 

 ers of the mesozoic age, and to have been interme- 

 diate between a hippopotamus and a dolphin, and 

 omnivorous in diet. As this animal is altogether 

 unknown to geology or zoology, and not much less 

 difficult to account for than the whales themselves, 

 ^ Reported iu 2t^ature. 



