Feb., 1903.] 



A Hermit Thrush Song. 



371 



beginning to appear while the third leaf would have the normal 

 form of the mature plant. On this account I regard this as a 

 case of atavism rather than an ordinary" mutation ; or it is prob- 

 able that the watermelon embr3'o, in passing from entire to lobed 

 leaves, is repeating some of the past stages in the histor}- of its 

 race. Striking variations, mutations and reversions should be 

 carefully studied and recorded, since it is by them alone that 

 man}' of the problems of evolution can be solved. 



A HERMIT THRUSH SONG. 



Theodore Ci^arke Smith. 



During the summer of 1902 I stayed from tlie twenty-fourth of 

 June to the thirtieth of July at a camp on the shore of Lake 

 Memphremagog. My tent was placed at the edge of a cedar and 

 hemlock grove, mixed with occasional maples and birches which 

 furnished nesting places for a great variety of birds. The most 

 conspicuous singer was a hermit thrush whose nest was not far 

 from the tent and whose song was heard every morning and eve- 

 ning and frequently during the day for over a month. Others of 

 his kind were also audible, sometimes close at hand, but none 

 became so thoroughly familiar as this "camp thrush." I have 

 heard him at extremely close range, on one occasion from less 

 than ten feet, and have also been able to distinguish his song, 

 over the lake, from a distance of fully three-quarters of a mile. 

 From an abundance of material the following notes are contrib- 

 uted in the effort to analyze his vocal performance : 



In form the song of this thrush was very distinct, clear-cut and 



regular. His typical phrase was as here 

 shown. This same form was repeated by 

 the bird in higher keys, usually some- 

 what simplified by the omission of one or 

 more of the latter notes until at the top of 

 the bird's register it become reduced to 

 little more than the following. The closer one approached the 

 thrush the greater appeared 

 the regularity, as long, that 

 is, as the bird was in full 

 song, for when beginning or 

 when singing softl}- he depart- 

 ed noticeably from his ordin- 

 ary practice. 



On several occasions the 

 bird sang near the camp cabin in which there was a piano, and it 

 was a simple matter, owing to the regularity of the song, to deter- 



