STERNUM OF THE CORMORANT. 393 



finding the greater part, if not the whole, of their 

 food in the waters, and descending upon it on the 

 wing, instead of getting it by wading or by walking, 

 as is the case with the groups last mentioned. Hence, 

 in all the varieties, they have a sternum well adapted 

 for flight ; but it also combines another character, 

 which will be better understood after examining the 

 following figures of the sternal apparatus of the com- 

 mon cormorant, which are given of half the lineal 

 dimensions of nature. 



It is however in the next figure, which is the pro- 

 file on the same scale, that the peculiar modification of 

 the sternum of these birds is best seen. 



Upon examining the following profile figure, it will 

 be found that this bone presents a still more power- 

 fully-resisting arch to the front than that formerly 

 alluded to in the divers. The anterior edge of the 

 keel, the coracoid, and the clavicle, form a complete 

 egg-shaped structure, with its narrow end in the head 

 of the last bone, where it is greatly increased in 



