248 TEET ADAPTED FOE 



or run. The preceding is the form of the foot, three 

 toes before, with short membranes at the bases, and 

 a sort of cartilaginous heel, but no back toe. 



Birds wliich frequent very soft surfaces, have gene- 

 rally the toes longer, and bordered more or less with 

 membrane : but unless there is another action besides 

 walking to be performed, the ditference of structure 

 in the feet is not, in the case of winged birds, very 

 great, whether they walk on . the earth, or wade in 

 shallow water over surfaces of the same kind. 



FEET FOB WALKING ON GRASSY SURFACES. 



These have the three front toes free to their bases, 

 and the hind toe articulated on the same level. The 

 claws long, the hind one especially, but not much bent. 

 These feet extend over a lars-e base, and the elasticity 



Sky-lark. 



of the grass assists the bird in jerking upwards till it 

 can take wing. The foot of the skylark is an 

 instance. 



FEET FOR WALKING UPON AQUATIC PLANTS. 



These have the toes very long, and the birds which 

 have them can generally swim. The common galli- 

 nule, or water-hen, is an instance of this form oflfoot 



Some of the foreign birds of the same sroup 

 iMacrodactyli) have the toes much longer in proper- 



