70 DWIGHT E. MINNICH 



in a cage where it was kept without food or water. After three 

 days, trials were begun with all four substances and were con- 

 tinued until the butterfly gave 100 per cent response to distilled 

 water; that is, complete extension of the proboscis in each of the 

 four trials of the day. In a few cases the experiment was con- 

 tinued for a day or so beyond this point before making any change 

 in the nutritional conditions. In general, however, this was not 

 possible because of the growing weakness of the specimen and the 

 danger of its death. 



When the experiment had reached the stage described, at the 

 conclusion of the trials for the day the butterfly was placed on 

 absorbent cotton saturated with distilled water and allowed to 

 drink all it would. On the following morning it usually appeared 

 quite revived. Before resuming trials, however, the animal was 

 again given an opportunity to drink. If it failed to respond to 

 the water, I several times forced an extension of the proboscis by 

 touching one of the tarsi with sugar solution. Thus while the 

 animal could not be compelled to drink, it could be compelled 

 to bring the proboscis in contact with water. In this manner 

 it was offered water in the morning, one hour before trials 

 were begun, and in the evening, immediately after trials were 

 concluded. 



The butterfly was continued on this water diet until it again 

 became so weak that further trials were impossible, whereupon 

 experimentation was discontinued for the remainder of the day, 

 and IM saccharose was administered. Of this solution the 

 animal always imbibed freely, and it was not until the abdomen 

 was greatly distended that it ceased to feed. On the following 

 morning it would again appear quite restored, and trials were re- 

 sumed. The saccharose diet was continued for 3 to 4 days, 

 administrations being made twice daily as in the case of water. 



Following the period of saccharose diet, the butterfly was again 

 kept without water or food until the response to water rose to 

 100 per cent. Then followed a period of water diet, and when 

 this became insufficient, the sugar solution was again adminis- 

 tered. In other words, the three nutritional states described 

 above were repeated. 



