1 84 MAN, — THE ANIMAL 



wood frog, technically named, Rana sylvatica, was 

 selected for his experiments. He writes: "July 

 29, I placed 30 of the hairy caterpillars in the 

 cage. Rana sylvatica attempted to eat a cater- 

 pillar seven different times within an hour but re- 

 jected it each time. Following these trials no 

 other caterpillars were visibly reacted to. By at- 

 tempting to eat a caterpillar and then rejecting it 

 is meant this : The frog shot out the tongue in 

 the normal manner, bringing the caterpillar back 

 to the mouth, then extruding the tongue slowly, 

 slightly wriggling it. In most cases this muscular 

 wriggling freed the caterpillar from the tongue; 

 if it did not, the withdrawal of the tongue into the 

 mouth scraped off the caterpillar in nearly every 

 case. On August 9, 12:30, the caterpillar was 

 placed in the cage again; Rana sylvatica reacted 

 first by making two short hops to orient so as to 

 look directly at the caterpillar. (The caterpillar 

 was about 5 cm. in front of the frog.) The head 

 of the frog was then slowly lowered and brought 

 forward toward the caterpillar, but I could not see 

 that the tongue was shot out, although I watched 

 especially to see if this would happen. In a second 

 or two the head was lurched forward a little more 

 and then the tongue was very slowly extended, 

 barely touching the caterpillar. The tongue was 

 now withdrawn and then suddenly extruded, with 

 what appeared as a very slight attempt to shake 



