l8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



14 live ones were tested. They vi^ere grouped in pairs by one being- 

 removed from its ow^n case and then being introduced into another 

 case containing a sister. When first put together, three pairs 

 attempted to fight, but soon became friends ; two pairs fought Hghtly ; 

 one pair fought quite forcibly; and one pair fought fatally. These 

 experiments were repeated once by using 19 more of the same lot 

 of bees from the same cage. The bees by this time were probably 

 eight or nine days old on an average. After being confined singly 

 four days, all were dead but eight ; these were tested as usual. Two 

 pairs showed no signs of hostility ; one pair attempted to fight ; and 

 one pair fought lightly. 



The foregoing experiments were repeated by employing middle- 

 aged workers which had been confined three or more days in one 

 of the wire-screen cases. As already shown these bees had lost the 

 hive odor. After a confinement of four days in the small observation 

 cases, three of them had died ; the remaining 16 were tested as usual. 

 Two pairs fought fatally ; one pair attempted to fight, and five pairs 

 showed no signs of hostility. This set of experiments was repeated 

 twice with middle-aged sister workers that had lost the hive odor 

 by being confined in a wire-screen case. After a confinement of four 

 days, only 26 live ones for both sets remained and they did not appear 

 entirely normal. When tested 10 pairs of them showed no signs of 

 hostility ; one pair attempted to fight ; one pair fought quite forcibly, 

 and one pair fought fatally. 



The small cases described above were discarded and 50 smaller 

 ones were constructed. Two sides of the latter cases were 4.5 inches 

 and the third side was 3.5 inches in length, the bottoms being wood 

 and the tops glass. The tops and bottoms fit so snugly that practically 

 all of the odor emitted by a bee remained inside the case. After 

 confining a single middle-aged worker from frame D of hive No. 67 

 in each of these cases for nine days, the remaining live bees were 

 tested as usual. Three pairs showed no signs of hostility ; three pairs 

 attempted to fight ; two pairs fought lightly ; four pairs fought 

 quite forcibly ; seven pairs fought fatally, whereby in one case both 

 bees were killed. When these results had been recorded, the remain- 

 ing live bees were again placed singly into the cases, and an hour later 

 a sister bee from frame D of hive No. (i^ was introduced into each 

 case. Twenty-seven pairs showed no signs of hostility ; three pairs 

 fought slightly; and one pair fought quite forcibly. 



The preceding experiments were repeated by using middle-aged 

 workers from a frame of hive No. 19. After a confinement of six 



