1902.] 209 



The same phenomenon frequently occurs naturally in a modified 

 and less noticeable way whenever the bees of a hive are flying, and 

 especially when they fly in spring-time, or after they have been con- 

 fined to their hive for a day or two by bad weather ; these being the 

 occasions when a number of young bees are more or less doubtful 

 as to the position of the entrance to the hive. At these times there 

 is considerable excitement around the entrance, and a certain number 

 of bees — from two or three to fifty or more — may be observed to 

 give expression to the " joyful hum." By so doing they indicate the 

 position of the entrance (1) to tired, heavily-laden, old, or chilled bees, 

 and (2) to young bees that are flying for the first or second time ; 

 thus much confusion and loss of bee-life are prevented. 



Again, when a swarm has lost its queen, the bees that first find 

 her will give expression to the " joyful hum," and the rest of the 

 swarm will then soon join them. 



From these facts it is evident that in the " joyful hum " bees 

 have a method of signalling to one another, which is of the greatest 

 value to them in keeping the members of a swarm or colony together. 



One would naturally imagine that the communication is effected 

 by the sound of the " hum." This pre-supposes that bees can hear. 

 Sir John Lubbock (now Lord Avebury), however, found that both 

 ants and bees are apparently insensible to ordinary sounds, although 

 he was disposed to think that ants (and bees ?) are able to perceive 

 sounds which we cannot hear. At the same time he found the 

 sense of smell to be highly developed in ants ; and of bees he said 

 that it seems clear they possess a keen power of smell ("Ants, Bees, 

 and Wasps," IS81). 



My experiments with humble-bees, which have extended over a 

 period of twelve years, have led me to similar conclusions with regard 

 to humble-bees. 



I will not enter here into the question as to whether bees can 

 hear or not, but these points are mentioned because it was in the 

 light of them that I was led to the idea that bees when giving expres- 

 sion to the "joyful hum " might at the same time emit an alluring 

 scent. 



When hiving a swarm in July 1900, T recognised a distinct and 

 somewhat pungent odour, something between that of formic acid and 

 iodine. About the same time I noticed that . all bees that gave 

 expression to the "joyful hum" in any of the ways above cited, 

 adopted a peculiar attitude. Each bee stood with the apex of the 

 abdomen more or less elevated, and she exposed a large portion of the 



