24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



of a foreign hive odor and an alien family odor held in check by the 

 drone odor. Since the workers used in these experiments were from 

 colonies having drones, it is probably true that they were already 

 accustomed to the drone odor, therefore this odor probably served 

 as a check to prevent all the drones from being attacked considerably. 

 Why all of the lOO drones tested in the third lo sets of experiments 

 were attacked considerably, might have been due to the combination 

 of all three of the above enumerated possibilities. In these last 

 experiments there was (i) a foreign hive odor, (2) a drone odor, 

 to which the workers employed were not accustomed because their 

 colonies were droneless, and (3) an alien family odor. 



All the preceding experiments were performed in July, 1913, after 

 the drone-killing time and when drones were comparatively few, but 

 very similar results were obtained during the following May before 

 the drone-killing time, and when drones were abundant. These 

 experiments were repeated several times on July 15, 1914, and the 

 results obtained were similar to those described. Other duties pre- 

 vented the writer from continuing this experimentation in view of 

 determining the relation between the odors produced and the factor 

 causing the killing of drones. Those who maintain that bees are 

 reflex machines, believe that a constant external stimulus is required 

 during the drone-killing time, and reasoning from this point of view it 

 might be possible that various factors cause the drone odor to change 

 so that it might serve as the external stimulus to indicate to the 

 workers that the drones must be killed. 



According to the data obtained in all of the foregoing experiments, 

 there is little evidence for the existence of a family odor in drones, 

 but since it has already been shown that workers have a family odor, 

 it is reasonable to think of drones also inheriting a family odor. 

 These experiments do not prove conclusively that drones carry the 

 hive odor, but since workers and queens carry the hive odor, it is 

 logical to regard the drones in the same light. This possibility is 

 further strengthened by the fact that all the combs, frames and even 

 walls of the hive body are scented with the hive odor. After leaving 

 small blocks of wood or queen cages in the hives for a few days 

 and then removing them they give off the hive odor. According 

 to the results obtained in the foregoing experiments, it may be 

 inferred that drones when entering a strange hive are rarely molested 

 if this hive contains several drones, but when drones enter a droneless 

 colony they may be subjected to more or less hostility, although it is 

 generally believed that drones go unmolested at all times and under all 



