THE PALEONTOLOGIC RECORD 305 



if not the first, to bring the fruits of paleontology to the support of 

 evolution. But Leidy, as far as a hasty search through his writings 

 could reveal, nowhere expressly advocated the doctrine of recapitula- 

 tion. Indeed, he gave but little attention to the philosophical bearings 

 of paleontology, generally partly because of temperament and partly 

 because in those pioneer days material to serve as a basis for generaliza- 

 tion was still scanty. 



Gaudry, one of the first European paleontologists to champion the 

 cause of evolution, 2 likewise did not specially advocate the doctrine 

 of recapitulation. An examination of his " Philosophic Paleontolo- 

 gique " fails to reveal any definite belief in this doctrine. 



Huxley, as far as I can gather from his papers and essays, be- 

 lieved in this doctrine, though with certain implied reservations as to its 

 general applicability. In his presidential address to the Geological 

 Society of London on " Paleontology and the Doctrine of Evolution " 

 delivered in 1870, we find some interesting comment on the signifi- 

 cance of the splints of the living horse, which he regards as indicative 

 of the presence of three complete digits in the horse ancestor. But 

 Huxley was never an out-and-out advocate of the biogenetic law. 



Cope and Marsh, as we all know, were staunch upholders of evolu- 

 tion ; and Cope, at least, was also a staunch upholder of the doctrine of 

 recapitulation. In his " Primary Factors of Organic Evolution," his 

 last contribution to philosophical paleontology, he devotes considerable 

 space to proving this doctrine. He says : 3 



The representatives of each class passed through the stages which are 

 permanent in the classes below them in the series. 



And he backs up this proposition with evidence derived from the 

 ontogeny and phylogeny of batrachia, the antlers of deer and the blood 

 trunks of vertebrates generally. For all that, Cope recognized the 

 justice of certain criticisms which had been brought against the doc- 

 trine of recapitulation and urged caution in its application. 



An example or two of recapitulation may now be cited from the 

 field of the lower vertebrates. 



The mode of development of the teeth in Neoceratodus has some- 

 times been adduced as an illustration of recapitulation. It is well 

 known that the Devonic dipnoans (e. g., Dipterus) had teeth com- 

 posed of rows of denticles, those in each row being more or lesls fused 

 at their bases. During the history of the dipnoans since the Devonic 

 period, the separate denticles have merged more and more until in 

 Ceratodus and the living Neoceratodus, the rows of denticles are, in 



2 According to a letter from Darwin to Gaudry dated Januiry 21, 1868. 

 " The Life and Letters of Charles Darwin/' edited by his son Francis Darwin, 

 New York, 1899, Vol. II., p. 269. 



3 "Primary Factors of Organic Evolution," Chicago, 1890, p. 195. 



vol. lxxvii. — 21. 



