THE NATURALISTS VISION 353 



least two years old. Do not suggest any method 

 of song to them by whistling, or by singing, or 

 playing on any instrument. We will now con- 

 clude that their habits are fixed, and whatever 

 sounds they produce are at least not the outcome 

 of imitating other birds. Record the results ; and 

 not being satisfied with this, bring other competent 

 ornithologists to observe them and the end that 

 has been attained. 



Here, at least, is the beginning of an answer to 

 the question. To carry it a step farther; asso- 

 ciate a new brood of very young robins with the 

 birds first raised. That is, put this second brood 

 where they may hear and see what your first brood 

 does, if anything, in the way of song, and the mo- 

 tions connected with it. Observe and record the 

 results as with the original brood. Better still, 

 and it is entirely possible, for, as I have indicated, 

 under proper conditions even robins will breed in 

 captivity, mate a pair of the hand-reared birds. 

 You may observe what part inheritance or instinct 

 plays in building nests of the conventional type ; 

 and at the same time, when the second brood 

 arrives at the period of song, will they sing like 

 wild robins, two generations away, or not ? 



Finally, if song is an inheritance, that is, as 

 far as its method is concerned (for I have no doubt 

 that the disposition to sing is inherited in the 

 group of song-birds), let me present another 



2A 



