voi.xxxiiij gg^^2^ ^^^^^ ^^^ ^^^ ^.^^^ 291 



The moult of the down occurs in September of the first year at 

 the age of four months; the second moult of the down begins in 

 June at two years of age and continues all the summer and is com- 

 plete at the end of August. 



The adult Eider has two annual moults, the first in April and 

 May and is partial as it does not include the large wing and tail 

 feathers; the second moult occurs during the last of August and 

 the first of September and is complete including the large feathers 

 of the wings and tail. 



As a food the flesh of the Eider is good for the table fifty days 

 after it is hatched and continues to be good until the age of one and 

 a half years. During this period the young bird eats only prawns 

 and much herbage. After a year and a half the flesh has an oily 

 taste due to the fact that the bird takes at a great depth molluscs 

 and little fish. The very old subjects do not resort to the deep 

 water but return to the food of the young. Their flesh loses its 

 oily taste but is firmer than 'that of the young. 



Note. A study of the adult male specimens sent me by M. 

 Beetz, as well as those in the Museum of Comparative Zoology at 

 Cambridge, shows all degrees of gradation in the size of the mem- 

 branous processes from the long, broad rounded ones of dresseri to 

 the shorter acute ones of borealis as is to be seen in the accompany- 

 ing photograph. The amount of green also varies. In typical 

 dresseri it is extensive on the sides and back of the neck and forms 

 a border to the dark cap, extending forward beyond the eye. In 

 typical borealis it is less extensive on the sides and back of the neck 

 and does not border the dark cap. In M. Beetz's intermediate 

 form the amount of green varies, and it does not border the dark 

 cap. Baird, Brewer and Ridgway ^ were unable to find any other 

 differences between dresseri and borealis except in the size of the 

 membranous processes. They say " the extent of the green of the 

 head is quite variable, according to the individual." Coues ^ 

 speaking of the membranous processes in the two species says: 

 "The difference is obvious in comparison of specimens, and may 



1 The Water Birds of North America. 1884, Vol. II, p. 77. 



'- Key to North American Birds. Fifth Edition, 1903, Vol. II, p. 904. 



