NO. 2 RECOGNITION AMONG INSECTS McINDOO 1 5 



to two more of their sisters. One hundred workers from hive No. 19 

 were likewise tested on the fifth day ; they attempted to seize one 

 introduced bee and to sting the other one when introduced. One 

 hundred workers from hive No. 23 were also tested on the fifth day ; 

 they attempted to attack one introduced bee and did attack the other 

 one lightly ; on the thirteenth day two more were attacked lightly. 

 One hundred workers from hive No. "j}, were tested on the seventh 

 day ; both introduced bees were attacked lightly. 



According to the foregoing experiments it is evident that 30 or 

 more workers confined in a close-fitting case are able to form a 

 new hive odor. This hive odor on the third day differs enough from 

 that formed in another similar case by sister bees to cause the bees 

 to attack each other more or less. The longer the bees are confined 

 in such captivity the more hostile they are to each other, however, 

 on about the tenth day of confinement middle-aged workers become 

 black and shiny, and their abdomens are much distended, due perhaps 

 to an accumulation of waste matter in the intestines. After the tenth 

 day their hostility does not usually increase because the bees from 

 then on gradually become less active. These results indicate that each 

 worker emits an odor which is at least slightly different from that 

 emitted by any other worker, and if this is true the hive odor is 

 chiefly composed of a combination of all the individual odors. 



Experiments dealing with the individual odor of bees were per- 

 formed on a larger scale by employing two Benton queen-mating 

 boxes and two wire-screen cages. The inside dimensions of a queen- 

 mating box are 1 5 by 9 by 9 inches. Small frames made purposely 

 for these boxes were used in the same manner in which full-sized 

 frames are used in standard hives. Each box has a cover which fits 

 rather snugly. The entrance was closed with wire screen and the feed 

 box was filled with water. Each cage consists of a frame work 

 made of narrow wooden strips nailed firmly together, and all six sides 

 of the frame work are covered with wire screen. The inside dimen- 

 sions of each cage are 12 by 10 by 10 inches. The cubical contents 

 of a box and of a cage, therefore are practically the same. Small 

 frames belonging to the queen-mating boxes were suspended in the 

 cages and a small tin pan containing water was put on the floor of 

 each cage. The four containers may be called boxes Nos. i and 2, 

 and cages Nos. i and 2. 



Two frames with nice comb containing much honey and pollen were 

 removed from hive No. 81. Each comb was equally divided into 

 halves and each half was inserted into one of the small frames and 



