ON THE COLYMBUS IMMER. 



253 



twelve pounds. The upper part of the plumage 

 is of a bluish-black colour, and the feathers being 

 edged with white, the whole has a speckled ap- 

 pearance. The under-part of the neck, breast, 

 and belly, are of a silvery whiteness, but a dark- 

 coloured bar crosses the vent. There is scarcely 

 any difference of plumage in the sexes, but I 

 think the male is the larger bird of the two. 



The imber possesses great strength, swims with 

 amazing rapidity, and is capable of remaining a 

 long time under water ; when it dives, it moves 

 by its feet only, and I have known it in this man-^ 

 ner, to traverse a space of more than 200 yardf?, 

 without performing a single respiration. It feeds 

 entirely on fish. The note is wild and melan- 

 choly ; and when wounded, and in dread of be- 

 ing taken, it utters a cry not unlike to the human 

 voice. 



In the month of November, the imber geese 

 are frequently met with in the bays in the Zetland 

 Islands, in small flocks of four, five, and six, but 

 the individuals composing them seldom approach 

 close to one another. Afterwards they associate 

 in pairs ; and in the middle of winter and spring 

 they are commonly met with singly.' From the 

 middle of summer to the end of autumn, they 

 are rarely seen, and this is the time when it 

 would appear they leave the country for the pur- 

 pose of propagating and rearing their species. 

 The circumstances of this bird being said never 

 to fly, nor to be met with on shore, have given 



