20 The Recapitulation Theory and Human Infancy 



10. Herbert Spencer. 



It is interesting to compare with the views of Haeckel the 

 position of another great systematist whose book appeared in 

 the same year with the "Generelle Morphologic." This book 

 is the "Principles of Biology" of Herbert Spencer. Spencer 

 makes his starting point von Baer's law and does not widely 

 depart from it throughout the account of his first edition. 

 He however cautions his reader against accepting the general- 

 ization as exact. The resemblances among related embryos 

 noted by von Baer "are not precise but approximate. Only 

 leading characteristics are the same: not all the details . . . . 

 each kind of organism, though having a general direction of 

 development like that of the others it is for a time traveling 

 with, shows from the first a tendency to leave the general route 

 a tendency which presently becomes strongly marked." Still 

 as an average truth the generalization may be regarded as be- 

 yond question. But, "the generalization must not be con- 

 founded with an erroneous semblance of it that has obtained 

 considerable currency. An impression has been given by those 

 who have popularized the statements of embryologists, that 

 during development each higher organism passes through 

 stages in which it resembles the adult forms of lower organ- 

 isms. . . This is not the fact." Thus Spencer repudiates 

 recapitulation in the form it was taking with Haeckel. 25 



In a later chapter where he presents with the others the 

 embryological arguments for evolution, Spencer is occupied 

 in showing that evolution explains not only the resemblances 

 of embryos but the lack of such resemblances as well. This 

 is due to the very unlike life conditions and consequent unlike 

 adaptations made by different groups in their evolution sub- 

 sequent to their departure from the common ancestor, adap- 



ogy. " Report of the British Association for the Advancement of Science, 1897, p. 682. 

 Compare also the following from Hyatt : 



"The use of terms indicating that Nature has confused or destioyed its own on to- 

 genetic records of the transmission of characters in certain cases assumes (1) that 

 these are exceptional cases, (2) that caenogenesis is not the normal mode of trans- 

 mission in certain types In which it occuis, (3) that both of these modes of trans- 

 mission are not affected by tachygenesis, all these implications being erroneous. 

 . . . "destruction," "confusion," or "falsification" are subjective terms inap- 

 plicable to the objective character of the phenomena . . . entirely out of place 

 In natural science." Phylogeny of an Acquired Characteristic, p. 401, footnote. 



VoL 1. 1st American ed., 1898. pp. 143, 144. 



