NATATORES. PODICEPS. 391 



in the form of their feet, were arranged with the Coots and 

 Phalaropes (birds also belonging to different families), and 

 formed a truly artificial division, under the title of Pmnati- 

 pedes. Instead of the free tibia, and the gressorial foot, cal- 

 culated for progress upon land, and at the same time fur- 

 nished with distinct membranes to assist in swimming, as we 

 see exemplified in the Coot, the feet of the Grebes are 

 formed upon a very different plan, and expressly adapted 

 for the watery element, as the position of the tarsus and the 

 articulation of the toes are such as to give no stability to the 

 body upon land, and progression there is effectually prevent- 

 ed by the restrained action of the tibiae. Except in the toes 

 being separated towards their extremities, and each furnished 

 with a distinct web, the form of the legs and feet approaches 

 closely to that seen in the genus Colymbus ; the tarsus suffer- 

 ing an equal lateral compression, and the outer toe exceeding 

 the other two in length. The Grebes are remarkably active 

 in the water, which they never quit, as they even breed there ; 

 making their nests amidst the reeds and other strong aquatic 

 herbage that is found in the localities they inhabit. From 

 their shortness of wing, and want of tail, they rise with dif- 

 ficulty, and scarcely ever have recourse to flight, except for 

 change of abode, or migration ; as, when pursued, they al- 

 ways endeavour to escape by diving. They feed on fish, 

 aquatic insects, and vegetables. The genus has a wide geo- 

 graphical distribution, some species being found in every 

 quarter of the globe. 



