THE SPADE-FOOT TOAD. 135 



velvety black ; but when closely examined it was found 

 that the two irregularly parallel, yellow dorsal stripes, 

 that are so prominent a feature in the coloration of the 

 adult male, were plainly discernible. 



The movements of these tadpoles were not different 

 from that of the young frogs and toads in this stage of 

 their existence. Those that I had in an aquarium moved 

 in companies as though following a leader, and occasion- 

 ally one would drop out of the ranks, come promptly to 

 the surface, eject a bubble of air, and dive again quickly 

 to the bottom of the tank. Like all tadpoles, they had 

 enormous appetites, and when fed with bits of raw meat 

 quickly attached their sucking mouths to the food of- 

 fered, and did not remove it, I think, while a particle 

 of blood remained in the mass. 



A week later, July 16, the majority of these tadpoles 

 had acquired their front legs, and the tail had per- 

 ceptibly diminished in size, but still was used by them 

 when moving through the water. At this time, how- 

 ever, the movements of the animal are far less active 

 than before or soon after, and for a few days, if exposed 

 to the attacks of any enemies, they would suffer far more 

 than at any other period of their lives. 



A very curious feature in the growth of these animals 

 is now to be noticed. Of the specimens I had under 

 examination, in an aquarium, about five per cent, did 

 not progress beyond the condition in which all were 

 on July 9. These " retarded " tadpoles proved to be 

 voracious cannibals. They seized their more matured 

 companions by their tails and legs, swallowing the mem- 

 ber, and thus sustaining their own lives at the expense 



