AUGUST 14, 1896.] 



SCIENCE. 



187 



ignored in any comprehensive theory of 

 evokition. This, again, is too large a field 

 to enter upon at the close of a lecture. It 

 must suffice, therefore, to hint at the many 

 cases in the existing distribution of animals, 

 which seem so puzzling and capricious, and 

 which are so readily explained by a study 

 of the past. That the nearest allies of the 

 South American llamas should be the 

 camels of the Old World seems unaccount- 

 able, until we learn that North America 

 was the original home of the entire tribe. 

 The occurrence of the tapirs in South Amer- 

 ica and in the Malay peninsula becomes in- 

 telligible enough, when we learn that this 

 genus is of very high antiquity, and was 

 formerly represented in every part of the 

 northern hemisphere. 



The more fully the past is recovered, the 

 more completely the former land connec- 

 tions of the various continents are made 

 out, the more comprehensible do the seem- 

 ing anomalies of the present order of things 

 become — a proposition which applies to 

 more than problems of geographical distri- 

 bution. 



The foregoing consideration of paleontol- 

 ogy as a branch of morphological science 

 is necessarily brief and very inadequate, 

 but it will suf&ce, I trust, to show that its 

 claims upon the attention of morphologists 

 should not be ignored, and that it is admi- 

 rably fitted to throw light upon many ob- 

 scure problems. In conclusion, let me 

 point out that final and lasting results are 

 not to be gained by an exclusive adherence 

 to any method of morphological inquiry, 

 but by a combination of all of them. Each 

 is able to supplement the others, and it is 

 folly to reject such aid. Already most en- 

 couraging results have followed from this 

 combined method of work, and it is de- 

 voutly to be wished that its scope may be 

 more and more extended. As an example 

 may be cited the recent investigations upon 

 the mammalian dentition. From paleonto- 



logical phyla we have learned to distinguish 

 the homologies of the cusps, and the way 

 in which a complex tooth is gradually formed 

 from a simple one. Embryology, on the 

 other hand, has shown the relations of the 

 successive dentitions to one another in a 

 fashion that paleontology could by no pos- 

 sibility accomplish unaided. As another 

 example may be mentioned Wiucza's dis- 

 covery of a bony clavicle in the embryo of 

 the sheep, which was soon followed by the 

 still more unexpected one of vestigial bony 

 clavichs in certain extinct artiodactyls, 

 confirming and explaining the first. Em- 

 bryology has taught us that the large ele- 

 ment in the carpus of the Carnivora known 

 as the scapholunar was formed by the 

 coalescence of three separate bones — the 

 scaphoid, lunar and centrale. Later the 

 fossils were unearthed, which showed that 

 the embryonic and transitory condition of 

 the modern forms was the permanent and 

 adult structure of the primitive Eocene 

 flesh- eaters. 



The more the combined method is em- 

 ployed the more fruitful does it appear. 

 Nor should the combination be restricted to 

 the technically morphological subjects. Ex- 

 perimental embryology has already won 

 some notable triumphs, and that is a physio- 

 logical quite as much as a morphological 

 province. 



In the ever-increasing complexity of 

 modern civilization a more and more im- 

 portant role is played by systematic co- 

 operation, specialists combining for joint 

 work which neither could accomplish alone. 

 Is it Utopian to wish that some such organ- 

 ized scheme of attack upon biological 

 problems shall be devised, when, instead of 

 every man doing merely that wliich is right 

 in his own eyes, we shall combine in a defi- 

 nite, orderly way to investigate a given 

 topic in all its bearings ? It may well be 

 doubted whether any naturalist, however 

 great his genius, will ever again be able 



