58 HYMENOPTERA CHAP. 



many have declared that the bumble-bees do not know how to 

 build. 



Although the species of Bombus are not comparable with the 

 hive-bee in respect of the perfection and intelligent nature of 

 their work, jet they are very industrious Insects, and the con- 

 struction of the dwelling-places of the subterranean species is 

 said to be carried out in some cases with considerable skill, a 

 dome of wax being formed as a sort of roof over the brood cells. 

 Some work even at night. Tea has recorded the capture of a 

 species in Upper Burmah working by moonlight, and the same 

 industry may be observed in this country if there be sufficient 

 heat as well as light. Godart, about 200 years ago, stated that 

 a trumpeter-bee is kept in some nests to rouse the denizens to 

 work in the morning : this has been treated as a fable by 

 subsequent writers, but is confirmed in a circumstantial manner 

 by Hoffer, who observed the performance in a nest of B. ruderatus 

 in his laboratory. On the trumpeter being taken away its office 

 was the following morning filled by another individual. The 

 trumpeting was done as early as three or four o'clock in the 

 morning, and it is by no means impossible that the earliness of 

 the hour may have had something to do with the fact that for 

 200 years no one confirmed the old naturalist's observation. 



One of the most curious facts in connection with Bomlnis is 

 the excessive variation that many of the species display in the 

 colour of the beautiful hair with which they are so abundantly 

 provided. There is not only usually a difference between the 

 sexes in this respect, but also extreme variation within the 

 limits of the same sex, more especially in the case of the males 

 and workers ; there is also an astonishing difference in the size 

 of individuals. These variations are carried to such an extent 

 that it is almost impossible to discriminate all the varieties of a 

 species by inspection of the superficial characters. The struc- 

 tures peculiar to the male, as well as the sting of the female, 

 enable the species to be determined with tolerable certainty. 

 Cholodkovsky, 1 on whose authority this statement as to the sting 

 is n uide, has not examined it iu the workers, so that we do not 

 know whether it is as invariable in them as he states it to be 

 in queens of the same species. According to Handlirsch,' each 



1 Zont. An;, vii. 1884, p. 312. 

 2 SJ3. Gcs. Wien. xxxviii. 1888, p. 34. 



