1893. PHETRECAPITULATION THEORY. 369 
I do not deny that there may be exceptions to this last statement. 
I deny that any one of the theories as to the ancestry of the 
vertebrates based exclusively on embryological grounds is worth the 
paper it was written on. 
I maintain that much otherwise good embryological work has lost 
much of its value through the bias produced in the minds of the 
writers by the dominancy of the idea of recapitulation. 
Comparative anatomy gives some help: Paleontology may give 
even more: by their aid embryological facts may be explained : but 
the facts of paleontology can never be discovered by the study of 
embryology. 
*« Vestiges,”’ and these only, can give any embryological clue to 
past history which could not be equally well made out from com- 
parative anatomy. In this last I may be wrong. 
I maintain that the applicability of von Baer’s law to even a 
single case would be a definite and final disproof of the Recapitulation 
Theory even in its most reasonable forms. 
Finally, I assert that the applicability of von Baer’s law in a large 
number of cases is capable of being readily proved by anybody, by a 
direct appeal to Nature, 7.e., by the study of a few vertebrate embryos 
taken at random. 
C. HERBERT Hurst. 
2B 
