LIMBS AND TOES 



9 



ans. Some of tlie tailed forms have horny tips on 

 their toes all the time ; others have these at certain 

 seasons only, when they chase or grasp each other. 

 These latter are on the fore feet, and are shed later. 

 In Africa, there is a frog armed with spurlike claws 

 on three toes of the hind feet, and our own spade- 

 foot toad (Fig. 5) has a tlat spur on its rear foot, which 

 is evidently used as a burrowing implement. 



The feet of the so-called Surinam toad (Fig. 6) 

 {Pijxi) are tipped with a starlike sprangle. The rule 



Fig. 5.— Spadefoot frog {Scajihiopus Iwlbrookii). 



among frogs and toads is that the rear toes are webbed 

 and the front ones are not. The leni^th of rear toes 

 and the extent of the webs vary much. 



