By the Rev. A. C. Smith. 



299 



often terminated with hooked claws; to detach which from the 

 wide gaping mouth, and from the bristles with which the upper 

 mandible of the beak is fringed, this comb-like claw is probably 

 appended to the foot ; I say probably, for much difference of opinion 

 has existed with reference to its use. Gilbert White and others 

 after him thought they could perceive the bird put out its short leg 

 while on the wing, and deliver something into its mouth, and thus 

 accounted for its use, that it enabled the bird to hold more securely 

 in its foot the insect it had caught; but for such a purpose it 

 certainly seems but very ill calculated. 



The "Swift" furnishes another instance of remarkable structure 

 of foot. As it passes the livelong day in unceasing and rapid flight, 

 it requires no great development of leg and foot; thus the tarsus 

 is exceedingly short and thick, so short as to render the bird in- 

 capable of rising from a flat surface, and therefore it never alights 

 on the ground ; for rest and for incubation it retires to the eaves of 

 steeples and towers, to the perpendicular walls of which, and to the 

 face of cliffs, its foot is well adapted to cling; thus it consists of 

 four toes, all of which are directed forwards, and are armed with 

 very hooked claws, and quite divided, and which give it the appear- 

 ance of belonging to a quadruped rather than a bird. 



The " Woodpeckers" are also furnished with feet most suitable 

 to their climbing habits; each foot is provided with four toes, 

 arranged in pairs, two directed forwards and two backwards ; these 

 afford an immense support, and as they are very strong and termi- 

 nate with hooked claws, it may be conceived what useful instruments 

 they must be to birds whose lives are passed in climbing about the 

 trunks and branches of trees ; indeed very similar in form are they 

 to the iron crampions which the Swiss chamois hunter affixes to 

 the soles of his feet, when about to scale the precipices of the Alps, 

 and climb among the dangerous chasms of the glacier. 



Again, the "Avocet" is provided with feet of singular construction ; 

 this bird is a wader in every sense, deriving its food from the softest 

 mud at the estuaries of rivers; to support it on which no ordinary 

 feet would suffice ; we see the toes therefore united for a considerable 

 part of their length by a concave membrane, not wholly webbed, 



