58 EVOLUTION 



recapitulation. We infer the pedigree from 

 the development, and then say that the 

 development recapitulates the pedigree. But 

 this is not quite so bad as it seems, since no 

 racial history or phylogeny is worth consider- 

 ing for a moment that does not show the 

 anatomical affiliation of actual forms, whether 

 living or fossil, and embryological investiga- 

 tion cannot do more than suggest clues. 

 Again, we consider the eircuitousness of the 

 frog's life-history and find in it an evidence 

 of the reality of recapitulation. We say that 

 in the development of many of its organs the 

 frog repeats steps which were taken by the fish 

 stock from which the race of Amphibians 

 sprang. We then use this as one of " the 

 evidences of evolution " which we have 

 already assumed. But the fallacy here is 

 simply that we cannot directly demonstrate 

 the truth of the doctrine of descent; we can 

 only bring forward facts which suggest it, 

 and which it serves to interpret. 



When all is said, then, there remains good 

 reason for keeping firm hold of this idea, 

 which was first clearly stated in its full 

 evolutionary importance by Haeckel, first in 

 his notable " Generelle Morphologic," and 

 later in his more popular treatises. This he 

 termed the " fundamental biogenetic law " 



