i8 DARWINISM TO-DAY. 



the first revealing of the phenomena of ontogeny led bi- 

 ologists to expect and even to anticipate has confessedly not 

 been forthcoming in that overwhelming measure hoped for. 

 The evidence is excellent and positive and there is much of 

 it, but the proof that man is descended from a fish because 

 he has gill-slits at one period in his individual development 

 is not of the sort to rely on too confidently. The recapitula- 

 tion theory of Fritz Miiller and Haeckel is chiefly con- 

 spicuous now as a skeleton on which to hang innumerable 

 exceptions. But the scientific evidence for descent which 

 embryology offers is neither weak nor slight; it is only less 

 overwhelming and all-sufficient than its too sanguine early 

 friends and sponsors attributed to it. 



The specific character of the evidence for the theory of 

 descent derived from the three chief sources just mentioned 

 cannot claim our attention here. Knowledge of it is cer- 

 tainly the attribute of all educated readers. If any one 

 should desire to refresh his memory of it, he may readily do 

 this by reading his Darwin, or Wallace, or Huxley, Haeckel,, 

 Spencer, Weismann, Romanes, Marshall, Cope, 4 et al. 

 What may for the moment detain us, however, is a reference 

 to the curiously nearly completely subjective character of 

 the evidence for both the theory of descent and natural 

 selection. Biology has been until now a science of observa- 

 tion ; it is beginning to be one of observation plus experiment. 

 The evidence for its principal theories might be expected to 

 be thoroughly objective in character; to be of the nature of 

 positive, observed, and perhaps experimentally proved, facts. 

 How is it actually? Speaking by and large we only tell 

 the general truth when we declare that no indubitable cases 

 of species-forming or transforming, that is, of descent, have 

 been observed ; and that no recognised case of natural selec- 

 tion really selecting has been observed. I hasten to repeat 

 the names of the Ancon sheep, the Paraguay cattle, the 

 Porto Santo rabbit, the Artemias of Schmankewitch, and 



