1909 J Brewster, Barrow's Golden-eye in Massachusetts. 157 



islandica. He seems to have been familiar with them, living as 

 well as dead, for he was accustomed to watch them swimming in 

 pairs and small flocks in Digby Basin and to handle freshly killed 

 specimens, apparently in some numbers. Hence his testimony 

 regarding them is of importance and entitled to careful considera- 

 tion. Without doubt it may be relied on as far as it relates to 

 the adult males of the two species, concerning which he discovered 

 that the trachea, bronchi and lower larynx of the one are very unlike 

 those of the other; the difference being illustrated by a plate that 

 accompanies his article. But his impressions respecting the 

 females and immature males are, in my opinion, somewhat less 

 trustworthy; indeed I cannot help suspecting that some of them 

 were based on wrong identification of specimens. Thus he asserts 

 — or at least plainly implies — that the female of americana is 

 quite as likely as that of islandica to "have nearly the whole of the 

 bill" yellow — which is contrary to my experience — and he is 

 quite positive that the female of islandica sometimes possesses an 

 entirely black bill — which I have never known to be the case. 

 Nor can I agree with him in thinking "that the yellow is only as 

 it were a transient mark of the young, and that the adults of both 

 species have dark bills." I should be equally unwilling to support 

 the reverse of this proposition, however, since the presence or ab- 

 sence of bright yellow does not seem to me to be often if ever de- 

 pendent on age. Dr. Gilpin's final conclusions are given on page 

 398 of his paper in the following quaint but expressive language : — 

 "Here then w r e have two species, in the male easily distinguished by 

 colour, but in the female by colour impossible, and our only guide 

 is that the Rocky Mountain bird [islandica], though larger, has a 

 shorter and higher bill, and in consequence of this height a differ- 

 ence in the shape of the forehead, where the feathers meet the 

 culmen, tolerably well enough shown in the male adults, but more 

 obscurely in the females and young — all being in the recent state, 

 and in the dried or mounted specimens scarcely discernible." To 

 this he adds (on page 399), "in the females as regards colour no 

 difference can be found." 



Although Dr. Gilpin's conclusions may be sound enough in the 

 main I do not consider them perfectly satisfactory in so far as they 

 apply to female birds. In dealing with these he was evidently 



