288 ANSERES. 



the foot in the water an impetus, which is very 

 advantageous in swimming. The tarsus is com- 

 monly flattened sidewise, that less resistance may 



FOOT OF PELICAN. 



be offered to progression in so dense a medium. 

 " In order to make the stroke, the foot is first 

 drawn forwards, when the toes close together and 

 the webs fold, so as to offer to the water the least 

 possible resistance ; but when the back stroke is 

 made, the toes spread out, while the action of the 

 limb is at the same time, in most instances, ob- 

 liquely outwards." 



The form of the body is flattened, not however 

 laterally as in the Waders, but horizontally, the 

 better to float on the surface ; the breast-bone is 

 very long, affording a bony protection to the greater 

 portion of the intestines. The plumage is remark- 

 ably thick and close, particularly on the under 

 parts of the most aquatic kinds ; besides which 

 the skin is furnished with a dense coat of soft 

 down. The outer surface of the plumage is in 

 general polished and satiny, having the property 

 (perhaps from being anointed with an oily secre- 

 tion frequently applied by the beak) of throwing 



