CRAB FEET. 265 



not a very close one, except in some of the foreign 

 species of goat-sucker ; and then, so far as the habits 

 are known, even these are very different. 



All the three leading organs, the bills, the wings, 

 and the feet, are so peculiar in these birds, that 

 almost any of them might be made the ground of 

 classification. The wings are the most powerful part 

 of the organisation, more especially of the diurnal 

 ones ; but even the feet are very characteristic. They 

 are not walking or perching feet, they are simply 

 adhering ones ; and though both the tarsi and the 

 toes are comparatively small and feeble, they are 

 very beautifully adapted for retaining their hold, be 

 the position of the body what it may. 



Though the description of prey is very different, 

 and the feet are probably never used in the capture 

 or the killing of it, yet there is a remarkable analogy 

 in habit between these birds and the birds of prey ; 

 and this analogy holds even in the division into two 

 sections. All the swallow tribe are diurnal feeders, 

 feeding wholly upon insects, and capturing them on 

 the wing only, and by the snap of the bill, the sound of 

 which may be often heard when the birds are on the 

 chase. They are thus hawks, only they are hawks 

 in miniature ; and there is nearly the same distinc- 

 tion between the swifts and swallows as there is be- 

 tween the falcons and the short winged hawks. The 

 habits of the nocturnal ones are not so well known, as 

 the habits of nocturnal birds are much less open to 

 observation than those of diurnal ones ; and, there- 

 fore, it is not ascertained in what manner they cap- 

 ture their prey, though probably by the bill, which is 

 even wider in the gape than in the day-feeding spe- 

 cies ; but as the foot of some species at least is different, 

 they may use that in some instances in the capture of 



