640 JONATHAN KISSER 



When confined to shallow vessels, the actions of the tadpoles 

 of the toad and of the frog of approximately the same stage, 

 were somewhat different. In general, the frog tadpoles swim 

 along the vessel walls. The toad tadpoles, on the other hand, 

 move in all directions over the bottom or near the upper sur- 

 face of the water. 



When toad tadpoles came into the vicinity of the food, either 

 covered or open, the reactions seemed to indicate stimulation of 

 some kind. They swam from side to side, and often when near 

 the food would turn directly to it. When the food was found 

 the tadpoles attacked it very eagerly. When two packets had 

 been introduced the tadpoles did not remain upon the packet 

 without food nor did they nibble it as they did the one containing 

 food. 



3. Experiments 



a. First set of tadpoles. The records of several of the trials 

 are here given in detail: 



TIME 



8.20 Food packet placed in shallow dish containing eight tadpoles 



8.22 Food found by first tadpole 



8.23 Food found by second tadpole 

 8.39 Food found by six tadpoles 



8.50 The position of the food was changed 

 8.55 The food found by three tadpoles 

 8.57 The food found by five tadpoles 

 8.05 The food found by seven tadpoles 



In another trial a small piece of fish not covered was placed in the dish. 

 10.30 Food placed in dish containing eight tadpoles 

 10.40 Food found by six tadpoles 



In another frial two packets were placed in the dish, one with food, the 

 other without. 

 2.35 Food placed in dish with six tadpoles 

 2.43 All the tadpoles had found the food and were nibbling 



None of the tadpoles were at the false packet. 

 2.55 Reversed position of the two packets 

 3.20 Food found by five tadpoles 



In a similar trial with two packets, one containing fresh meat, the other 

 without. 

 10.42 Packets placed in dish with fifteen tadpoles 

 10.50 Food found by twelve tadpoles 

 10.56 Reversed position of packets 

 11.05 Food packet found by ten tadpoles 



