3o 4 THE POPULAR SCIENCE MONTHLY 



paper, records very interesting cases of recapitulation in the genus 

 Parasmilia of the Cretaceous. Bernard concludes that the coral colony, 

 like the graptolite colony and the bryozoan colony, behaves as an 

 individual. 



In the echinoderms the likeness of the stem ossicles and the devel- 

 opment of the anal plate of Antedon, to Paleozoic and Mesozoic forms 

 has become one of the stock illustrations of recapitulation. Jackson 

 has found interesting examples of recapitulation in the development of 

 the ambulacral and inter-ambulacral plates of echinoids. Miss Smith 

 has shown that the young Pentremites is exactly similar in form to the 

 adult Codaster. This is an extremely interesting case, for Bather has 

 independently, and from quite different data, come to the conclusion 

 that Pentremites is derived from Codaster. 



The idea of recapitulation has been one of the most fertile in the 

 whole realm of biology, and its usefulness to the paleobiologist has been 

 almost incalculable. But while there can be no doubt that recapitula- 

 tion is a fact, the paleontologist should observe all due care not to 

 assume too much for it. That there are various sorts of adaptations, 

 arising at all stages of life, and that these may greatly obscure the 

 ancestral record, is a fact too well known to require more than mention. 

 There is also always acceleration, sometimes affecting different char- 

 acters very unequally; and there may be retardation. All of these fac- 

 tors complicate the record of ontogeny. Nevertheless, after all of these 

 have been taken duly into consideration, the parallel between ontogeny 

 and phylogeny remains a powerful aid to investigation for the pale- 

 ontologist. 



VERTEBRATE PALEONTOLOGY AND THE EVIDENCES 



FOR RECAPITULATION 



By L. HUSSAKOF 



AMERICAN MUSEUM OF NATURAL HISTORY 



AFTER the careful papers of Professors Loomis and Lull in which 

 the doctrine of recapitulation was so fully set forth from the 

 standpoint of vertebrate paleontology, I can perhaps do no better than 

 devote part of the time allotted me to showing how certain leading 

 vertebrate paleontologists have viewed this question. Then I will cite 

 one or two illustrations of this principle drawn from among the lower 

 vertebrates. 



Passing over the period of pre-Darwinian paleontology — the pale- 

 ontology of Cuvier, Owen and Louis Agassiz — we come to the time of 

 Leidy, who, as Professor Osborn has recently shown, 1 was one of the first, 



1 In his address on " Darwin and Paleontology " printed in " Fifty Years 

 of Darwinism." Centennial addresses in honor of Charles Darwin, New York, 

 1909, p. 209. 



