206 DISEASES OF INSECTS. 



tells us a , follows, when the same experiment is re- 

 peated on the workers or drones : they immediately be- 

 come unable to take any further part in the labours of 

 the hive ; they can no longer guide themselves except in 

 the light ; if they petition one of their fellow-citizens for 

 honey, they are unable to direct their tongue to its mouth 

 to receive it ; they remain near the entrance of the hive, 

 and when the light is intercepted they rush out of it to 

 return no more. 



Insects occasionally are subject to tumours or a preter- 

 natural enlargement of their parts and organs. The an- 

 tennae of bees sometimes swell at their extremity so as 

 to resemble the bud of a flower ready to open, becom- 

 ing at the same time very yellow, as does the fore part 

 of the head b . I once saw a specimen of a Hydrobius 

 agreeing with H. fuscipes in every other respect even to 

 the most minute punctum which had a large tumour 

 on each side of the prothorax, evidently accidental, occa- 

 sioned probably by the stoppage of the pores by which 

 the superfluous moisture and air escape when it under- 

 goes its last change. The converse of this I have ob- 

 served to take place sometimes in the same part of Geo- 

 trupes foveatus, the ordinary later alfovete becoming very 

 considerably enlarged ; this was the case with the spe- 

 cimen from which Mr. Marsham made his description 

 of that insect. The species is, however, very distinct in 

 other respects, and may always be known by its small 

 size. It happens now and then also, that these tumours 

 represent blisters. I saw one once on one elytrum of a 

 beetle and not on the other. Those of Serroptilpus (as 



8 Huber Abeilles ii. 409. b N. Diet. d'Hist. Nat. i. 42. 



