OLFACTORY REACTIONS IN AMPHIBIANS 621 



Some days later, the same toads, Nos. 1 and 2, were again 

 tested with the dmigworms. Three worms of medium size placed 

 in the center of the box were immediately noticed by Toad No. 1. 

 No attempts to take any worms followed. The odor character- 

 istic of the worms was evident and the cutaneous exudate was 

 visible. A mealworm dropped into the vessel among the dung- 

 worms quickly became covered with the slime of the worms. 

 That the mealworm was recognized as a new object by the toad, 

 is proven by the actions of the toad. The attitude peculiar to 

 the animals when watching some object, was immediately as- 

 sumed. As soon as the mealworm had crept away from the 

 dungworms, the toad snapped it up. Another mealworm dropped 

 into a dish containing some fragments of dungworm was watched 

 by the toad as long as it moved. After it ceased moving it was 

 of no more interest to the toad. No attention was paid to the 

 fragments of dungworm although they were wriggling. A second 

 mealworm smeared with the exudate from the earthworm was 

 quickly snapped up by No. 1. This reaction was followed by 

 the wiping of the lips with the forefeet; whether this was done 

 to remove the slime adhering to the lips was not determined. 

 The wiping action again took place when the same toad took 

 another mealworm similarly prepared. Toad No. 2 exhibited 

 the same reactions under similar conditions. 



A series of trials with the different toads proved that frag- 

 mented dungworms were never taken, even though they ex- 

 hibited decided movements. The trials also showed that the 

 toads preferred the mealworms, and that the odor of the dung- 

 worms when applied to the mealworms was not deterrent to 

 the toads. 



Trials carried out with the same toads, to determine their 

 preference for mealworms over earthworms, indicated that 

 the mealworms were the more desired form of food. These 

 were selected from among the earthworms. It is not clear why 

 this should have been so; previously and later in the course 

 of the experiments both earthworms and mealworms were taken 

 promiscuously. • 



