8 THE ENTOMOLOGIST. 



emits a " very stimulating efflux iiim of aether ;" and he quotes 

 Pallas's observation on the Bombus fragrans " Iceminse odore 

 roseo fragrantissime," he having Inmself remarked the same 

 scent in a male of that species. Having myself discovered 

 the nest of B. fragrans, I can testily to the powerful and 

 agreeable scent emitted by a colony of this bee when their 

 domicile is disturbed, and the community thrown into a 

 panic of disorder. 



The species of the genus Nomada also exhale a very 

 agreeable perfume ; but 1 do not think all the parasitic bees 

 are odoriferous, not having observed it in the genera Epeolus, 

 Melecta or Stelis, but 1 cannot state positively of these 

 genera. 



Why some species of bees are, as it were, perfumed, and 

 others not so, it is difficult to assign even a satisfactory con- 

 jecture : when the odour they emit is so aromatic, reseuibling 

 that of herbs and flowers, we cannot imagine it to be a pro- 

 tection from enemies. Many hymenoplerous insects, how- 

 ever, emit most offensive exhalations ; I believe all the 

 Ichneumons do so in a greater or less degree : those be- 

 longing to the genera Pimpla and Rhyssa are very obnoxious 

 in that respect, whilst P. instigator and P. aethiops are most 

 disgustingly off'ensive. 



In the species of the genus CocHoxys we have an instance 

 of the same character, and when several individuals are held 

 in the hand together, whilst living, the odour they emit is 

 extremely offensive. Such a provision has doubtless a par- 

 ticular purpose : may it not be the means of securing the 

 parasite from molestation when engaged in the act of ovi- 

 posilion in the nest of the working bee ? Such may be the 

 case, but I have never observed any pugnacity exhibited by 

 the constructor of the nest towards the intruding parasite. 

 Shuckard records an instance of this kind : speaking of the 

 genus Anthophora, he sa} s, "They are subject to the para- 

 sitism of the genus Melecta, whose incursions are very repug- 

 nant to them, and which they exhibit in very fierce pugnacity, 

 for if they catch the intruder in her invasion they will draw 

 her forth and deliver battle with great fury." Such an occur- 

 rence can, I think, only be an occasional one, as 1 have 

 watched these bees issuing from and entering the burrows of 

 Anthophora, on very many occasions, without observing such 



