530 ORNITHOLOGY AND OOLOGY. 



feet of the bird. They are very thick-shelled, and, when 

 struck together, sound almost like balls of ivory. They are 

 more spherical in form than the eggs of any other duck that 

 I have seen, and are but little more pointed at one end than 

 at the other. Their dimensions vary from 2.30 by 1.75 

 inches (the longest and narrowest specimen in a large num- 

 ber in my collection) to 2.10 by 1.80 inches (the shortest 

 and broadest specimen in the same) : the usual size is, on 

 the average, about 2.13 by 1.70 inches. I am not aware 

 that any nest of this bird has been found south of Lake 

 Umbagog. 



When the nest of this species is approached, the female 

 remains quiet, and flies off only when alarmed by blows on 

 the trunk of the tree 'on which her nest is built. She then 

 flies silently, and alights in the lake, near which the nest is 

 usually built, and watches the intruder from a safe distance, 

 without making any outcries or disturbance. If the tree is 

 surrounded by undergrowth so thick that she cannot see the 

 intruder from the water, she flies silently over and around 

 him, always at a safe distance. The male never shows him- 

 self on such occasions ; and I think it likely that he separates 

 from his mate at the commencement of the period of in- 

 cubation, and remains by himself until the young are able 

 to provide for themselves. 



When living in the neighborhood of fresh water, this bird 

 has many of the habits of the other Mergansers, and then 

 feeds on aquatic insects and their larvae, and is an expert 

 fisher and diver. 



When the female is suddenly surprised, while with her 

 young in a stream or pond, she gives a guttural, chattel ing 

 cry, when the whole brood dives and swims off under water 

 to the shore, where they conceal themselves in the aquatic 

 herbage. While they are thus retreating, the mother simu- 

 lating lameness, almost exactly like some of the shore-birds 

 on the beach, flutters before the intruder, using every arti- 

 fice to decoy him from the neighborhood of her young, 



