304 T'HE 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 
FTER 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," was one of the first, 
1—n his address on “ Darwin and Paleontology” printed in “Fifty Years 
of Darwinism.” Centennial addresses in honor of Charles Darwin, New York, 
1909, p. 209. 
