FoKM AXi) iiAiuT: Till: i-m:I':t. 



29 



Sparrow:^ use Ixitli fret in scarcliiiif]^ for f(jO(l, jumping 

 (quickly backward and timtwini:; the leaves l>eliind tlieni. 



Parrots use their foot as a liaud. Scjnie Hawks carry 

 nesting material in it, and all hirds of 

 prey strike their (juarry with their 

 strongly curved claws, which are then 

 used to carry, or hold it while it is 

 being torn l)y the bill. The foot of 

 the Fish Hawk is a magnilicent organ. 

 The nails are strong and well curve<l ; 

 the inner surface of the toes is set with 

 sharp, horny spikes, and the outer toe 

 is partly reversible, so that the bird 

 grasps its slippery prey from four dif- 

 ferent points. 



As a weapon the foot is especially 

 effective, the use of spurs being too 

 well kno^vn to require comment. Os- 

 triches kick with their feet, and can, it is said, deliver a 

 blow powerful enough to fell a man. 



But by far the best instance of modification in the 

 structure of the feet is furnished by Grouse. It is an 



Fui. 15.— Foot of Fish 

 Hawk, sliowinir larire 

 claws, and spicules on 

 under surface of toes. 

 (Y3 natural size.) 



^ 



Fig, 16.— Nuked toes of liutfed (Jrouse in sutnmer ; fringed toes of Ruffed 

 (Jruusu in winter. (2/3 natural size.) 



unusual case of seasonal adaptation in form. During the 

 summer the toes of Grouse are bare and slender, but as 



