THE NATURALIST'S VISION 351 



to their own devices. At any rate, extended ex- 

 periment of this kind would go far toward being 

 an absolute demonstration of the mutability of 

 species as set forth in the hypothesis of evolution 

 by Charles Darwin. 



The vista presented is certainly an alluring one, 

 and vital problems await an answer. I have not 

 touched on the factors of heredity ; but I suggest 

 to those who have battled in a war of words with 

 Weissman, — a battle in which so much ink has 

 been spilled, — that data can be obtained as to 

 whether acquired characteristics are inherited. 

 Also that much can be added to our knowledge 

 in regard to prepotency, and that how great a 

 factor telegony is, may be realized after prolonged 

 experiment. 



To be more explicit, I propose to ask a ques- 

 tion, and to dwell on a method leading to its solu- 

 tion. It deals directly with one or another of 

 these problems. 



Do singing birds inherit the instinct of the 

 method of song, or must that method be acquired 

 by imitating the song of the parent ? That pas- 

 serine birds inherit a disposition to sing is 

 obvious ; but what of the method ? Is the song 

 of the robin as we hear it an inheritance or is it 

 a matter of education ? There are various theories 

 propounded in answer to this query substantiated 

 by hearsay, by probability, and by some partial 



