NO. 2 RECOGNITION AMONG INSECTS McINDOO 25 



conditions from hive to hive, except during" the drone-kilHng time. 

 It, therefore, seems that the drone odor serves as a check to reduce 

 the hostiUty caused by a foreign hive odor which is carried on the 

 bodies of the drones. 



7. ODOR EMITTED BY GUARDS 



In order to have a standard by which to judge the hostility exhib- 

 ited when testing guards, fanners, middle-aged workers inside the 

 hive, nurse bees, and pollen carriers all belonging to the same colony, 

 20 workers from the alighting board of a hive were put into each 

 of the 10 glass observation cases. These workers included both 

 guards and fanners taken promiscuously from the alighting board. 

 Ten more guards and fanners taken promiscuously from another 

 alighting board were introduced into the cases as usual. This set of 

 experiments was repeated nine times. Of the lOO strange workers 

 tested, each one was attacked fatally and most of them soon died, 

 perhaps on account of being stung. 



Twenty middle-aged workers from a- frame of hive No. 79 were 

 put into each of the 10 cases. A guard from the alighting board of 

 the same hive was introduced into each case. This set of experiments 

 was repeated nine times by using workers each time from a different 

 hive. Of the 100 guards tested, 54 were received without any signs 

 of hostility ; the bees ofifered to attack two ; nine were attacked very 

 lightly ; and 35 were attacked lightly. 



8. ODOR Emitted by fanners 



Twenty middle-aged workers from a frame of hive No. 81 were 

 put into each of the 10 glass observation cases. A fanner from the 

 alighting board of the same hive was introduced into each case. This 

 set of experiments was repeated by using bees from two other hives. 

 Of the 30 fanners tested, 14 were received without any signs of 

 hostility ; the bees offered to attack one ; three were attacked very 

 slightly ; and 12 were attacked slightly. 



9. odor emitted by middle-aged workers inside hive 



Twenty guards from the alighting board of hive No. 48 were 

 put into each of the 10 glass observation cases. A middle-aged 

 worker from a frame of the same hive was introduced into each 

 case. This set of experiments was repeated three times by using bees 

 from three different hives. Of the 40 middle-aged bees tested from 



