OLFACTORY SENSE OF THE HONEY BEE 295 



antennae of 100 pupae ranging in age from 14 to 18 days from 

 the laying of the egg were carefully cut off near the head. Great 

 care was exercised not to injure the immature bee in any way 

 other than by the amputation of these appendages. The cells 

 were again closed with a very thin layer of beeswax, a wire-cage 

 screen was placed over these uncapped cells so that the adult 

 workers could not pull the mutilated bees out of their cells, and 

 the frame was put into the hive. In a few days these bees began 

 to emerge from their cells. They were removed from the hive 

 and placed in observation cases with intact middle-aged bees. 

 All bees thus mutilated were abnormal and lived as adults about 

 5 days on an average. 



In like manner both antennae were cut from 300 pupae 13 and 

 14 days old from the laying of the egg. In this instance a wire 

 screen was placed over the entire frame so that the mutilated 

 bees could not escape when they emerged. Seven days later 

 they began to emerge and most of them in a short time crawled 

 from their cells. They soon mixed on this comb with other 

 young bees that were unmutilated and they had plenty of food 

 but they were all dead 5 days later. 



Seven of the workers with their antennae burned off recovered 

 from the operation sufficiently to eat candy and to move about 

 freely, but they were far from being normal. These lived from 

 1 to 11 days. When tested with the three essential oils, pep- 

 permint, thyme, and wintergreen, they responded readily. Their 

 general response was to move slightly and vibrate the stubs of 

 their antennae; one rubbed a leg against the abdomen and 3 

 moved their heads quickly. Average reaction time for oil of 

 peppermint 3.5 seconds, for oil of thyme 4.5 seconds, for oil of 

 wintergreen 4.3 seconds, and for all three oils 4 seconds. Fre- 

 quently, when the antennae were cut or burnt off, the insects 

 were placed on the table and tested with these odors. They 

 often moved away from the odors but generally did not react 

 to odors or anything else and often scarcely moved even when 

 touched with a pencil. 



In previous experiments bees cleaned off any substance put on 

 their antennae. To prevent this the tarsi of their front legs 



