196 



D WIGHT E. MINNICH 



in captivity. Eighteen of the animals were 51 to 75 hours old; 

 six, 50 to 98 hours old. None had received either food or water 

 after emerging from the pupae. Inanition greatly increased the 

 responsiveness of the animals, particularly to water, as tests 

 at various ages clearly demonstrated. During the first forty- 

 eight hours after hatching butterflies never responded either to 

 distance or to contact stimulation of water. After this period, 

 however, they began to respond more freely, and the number of 

 responses rose rapidly to nearly 100 per cent, remaining there 



TABLE 5 

 Pyrameis 



until the animals became moribund. Starvation, therefore, 

 renders the animals more responsive to water, and essentially 

 the same condition undoubtedly holds for food substances also. 

 The data from these experiments are presented in table 5. 



The results in the different experiments are very uniform and 

 bring out several facts clearly. First, each of the four solutions 

 employed may effect the proboscis response. Second, distilled 

 water alone is a very effective stimulus for the tarsi, being second 

 only to 1 M saccharose. Third, while all of the five substances 

 employed are able to effect the proboscis response, they are not 

 equal in this respect. The order of their effectiveness, based on 



