FEET OF SWIMMING BIRDS. 279 



water, would, of course, not be the most convenient. 

 The foot for action in the open water is a continuous 

 web of membrane between the toes, which varies with 

 the habit of the bird ; but among stems this web 

 could not be so conveniently used, as it would be 

 liable to get entangled or interrupted, if not torn. 

 Accordingly, these birds have the toes only lobed, so 

 that they can be drawn through between the stems 

 with the less opposition. Some of the birds which 

 have these partake of the character of shore or bank 

 birds, and can walk, upon the land as well as swim 

 upon the water. These are the coots and phalaropes, 

 which continue the succession from the gallinules, 

 which, through the landrails, have some relation to cer- 

 tain species of the gallinaceous birds. They, when on 

 land, carry the axis of the body in nearly a horizontal 

 position ; and the lobes on their toes are divided into 

 segments answering to the phalanges. Of these the 

 foot of the common coot is an instance. 



Grebes, though chiefly frequenters of fresh water 

 lakes, have much more aquatic habits. They have 

 the body of the true canoe shape, and the legs arti- 

 culated so far backwards, that they cannot support 

 the axis of the body in a horizontal position upon 

 land. They accordingly walk with the spine nearly 

 erect ; they walk with difficulty, and are never found 

 far from the water. Their feet have complete lobes 

 to all the toes, and even the tarsus is flattened, and 

 has a membranous margin, so that the foot is a swim- 

 ming foot all over, though one adapted to peculiar 

 places. The articulations of the tarsi have a rolling 

 motion, and those of the tibia also work outwards 

 when the feet act in swimming. The looseness of 

 these two joints renders the bird incapable of moving 

 along the ground with the legs steady ; and this, more 



