LIFE-HISTORY OF BOMBUS 13 



clearing in a wood, near some bushes or trees, one 

 is almost sure to see now and then a humble-bee 

 fly swiftly by and enter a dark hollow under a tree 

 or shrub, where it pauses for a second, almost 

 alighting, and then passes out and proceeds to 

 another recess, where it again pauses and almost 

 alights. Each succeeding bee flies in the same 

 direction and visits the same spots. If these bees 

 be caught, it will be found that they are all males 

 either of B . pratorum or B. hortorum. This strange 

 behaviour ot the male humble-bee has puzzled 

 many observers, but I have noticed certain facts 

 about it that point to an explanation. A sweet 

 fragrance, like the perfume of flowers, is perceptible 

 about the pausing places. This same fragrance 

 may be detected in the scent produced by a male 

 if he be caught in the fingers, although it is now 

 blended with an odour like that of sting-poison 

 emitted in fear. Evidently, therefore, the males 

 emit the perfume in their pausing places ; and I 

 think it extremely likely that in doing so they 

 attract not only one another, but the queens. The 

 males of the one species do not pause at spots 

 frequented by those of the other species, and we 

 may infer from this that each species emits a 

 different scent. 



The males of all the species are more or less 

 fragrant when captured, those of B. latreillellus and 

 B. distinguendus being especially so. The scent, 

 I find, proceeds from the head, probably from the 

 mouth. At the end of August 19 10, my study 



