56 THE PKINCIPLES OF HEREDITY 



recapitulation of the life-history of the race. No child could 

 develop unless there were recapitulation; but no race could 

 undergo extensive evolution unless the recapitulation were in- 

 complete and inexact. Shortened and emended, a life-history 

 is like some toilsome work begun by an inexperienced author 

 on insufficient knowledge and with half-formed plans. As his 

 knowledge grows and his plans take shape, every page is 

 altered. Almost every line is written over or erased. Passages 

 or chapters which were formerly important become irrelevant 

 and are omitted. New passages carry on the continuity of 

 the narrative. The finished work leaves few traces of its 

 life-history; yet not so few but that a skilful student may 

 detect here and there, by passages not quite in keeping with 

 the rest, traces of the method by which the author worked. 



93. The mode of development of every individual makes 

 recapitulation certain. 



" There is a history in all men's lives 

 Figuring the nature of the t*mes diseased." 1 



They are unskilful students who deny its existence. Its very 

 incompleteness is due to the recapitulation by descendants of 

 the regressive variations 2 of the ancestors. Naturally the most 

 ancient parts of the history are most incomplete and most 

 inexact, for on them variation has longest been at work. Even 

 if existing plant and animal forms had arisen by special creation, 

 there would still have been recapitulation. But in that case it 

 would have been recapitulation without variations. There 

 would have been no history ; or it would have been history in 

 a sentence. As it is, the dim and fleeting resemblances to 

 lower animals, displayed by the embryos of all higher types, 

 present the strongest evidence of the truth of the doctrine of 

 evolution that exists in the whole range of science. 3 We have 

 here a real history retold in every generation with the additions 

 and omissions made by the preceding generation a history 

 which ever grows longer with the lapse of years, and ever 

 more and more inaccurate and incomplete in its earlier parts. 

 94 We know that children follow in the developmental 

 footsteps of their parents. We know that they do so with 

 variations. We know there has been evolution. We know 

 that monsters are rarely produced, and that they perish when- 

 ever produced, and so leave no descendants. These facts 

 being known to be true, the truth of the doctrine of recapitu- 

 lation follows as certainly as if it had been mathematically 



1 Henry IF., III. i. 2 See 97. 



3 See Darwin and After Darwin, Komanes, vol. i., pp. 98-155. 



