APPENDIX. 



A SCENT-PRODUCING ORGAN IN THE ABDOMEN 

 OF THE WORKER HONEY-BEE. 



It has long been known that bees, under certain con- 

 ditions, particularly when swarming, will often, in vibrating 

 their wings, make a peculiar hum, aiid that in so doing 

 they attract their comrades. The attractive power has been 

 supposed to lie in the sound of the hum, but some observa- 

 tions that I have made have led me to the belief that it is 

 at least partly due to a scent which is emitted from a 

 membrane situate between the fifth and sixth dorsal seg- 

 ments of the abdomen. Ordinarily, this membrane is covered 

 by the fifth segment, but whenever the humming takes place 

 it is exposed and the scent is then given off.* The scent is 

 pungent and suggests a mixture of that of iodine with that 

 of formic acid. When humming and exposing the mem- 

 brane, the bee stands in a particular attitude, the legs are 

 extended and the tip of the abdomen is much raised, so that 

 the exposed membrane occupies an elevated position. No 

 doubt the vibration of the wings close to the elevated mem- 

 brane distributes the scent in a very perfect manner, t 



I first noticed the scent during the hiving of a swarm in 

 July, 1900, when hundreds of bees were exposing the mem- 

 brane. In March, 1901, while dissecting the abdomens ^i 

 several freshly-killed bees, I noticed that one of them g o 

 out the same scent. I then separated the membrane of this 

 specimen with as little of the surrounding integument as 

 possible, and placed it upon a piece of card. Here it 

 emitted the scent strongly for some minutes, whereas the 

 rest of the abdomen had no smell. On repeating the experi- 

 ment with another abdomen, a similar result was obtained, 

 but I found that not every specimen produced the scent. 



By squeezing the abdomen of a freshly-killed bee so that 



* A Tibratiom of the wings accompanied by little or no exposure of the 

 membrane takes place at the entrance of the hive in very hot weather. 

 Bhis is evidently for ventilation. 



t The le^s are extended, the tip of the abdomen raised, and the wings 

 Vibrated feebly by the bees that thTust out their stings in alarm when a 

 hive is opened. The sting poison, which gathers Ib little drops on the tips 

 of the stings, has a strong scent, which resembles that of jarm)nelle, and 

 has the effect of alarming other bees and inducing them to sting. 



