332 



LUMINOUS INSECTS. 



common female glow-worm having usually contented them- 

 selves with stating that the light issues from the three last 

 ventral segments of the abdomen \ I shall give you the 

 result of some observations I once made upon this subject. 

 One evening, in the beginning of July, meeting with two 

 of these insects, I placed them on my hand. At first their 

 light was exceedingly brilliant, so as to appear even at the 

 junctions of the upper or dorsal segments of the abdomen. 

 Soon after I had taken them, one withdrew its light 

 altogether, but the other continued to shine. While it did 

 this it was laid upon its back, the abdomen forming an angle 

 with the rest of its body, and the last or anal segment being 

 kept in constant motion. This segment was distinguished 

 by two round and very vivid spots of light ; which, in the 

 specimen that had ceased to shine, were the last that dis- 

 appeared, and they seem to be the first parts that become 

 luminous when the animal is disposed to yield its light. 

 The penultimate and antepenultimate segments each ex- 

 hibited a middle transverse band of yellow radiance, ter- 

 minated towards the trunk by an obtusely-dentated line ; a 

 greener and fainter light being emitted by the rest of the 

 segment. 



Though many of the females of the Lampyrida are without 

 wings, and even elytra (in which circumstance they dhTer from 

 all other apterous Coleoptera), this is not the case with all. 

 The female of Pygolampis 2 Italica, a species common in Italy, 

 and which, if we may trust to the accuracy of the account 

 given by Mr. Waller in the Philosophical Transactions for 

 1684, would seem to have been taken by him in Hertford- 

 shire, is winged ; and when a number of these moving stars 

 are seen to dart through the air in a dark night, nothing can 

 have a more beautiful effect. Sir J. E. Smith tells us that 

 the beaus of Italy are accustomed in an evening to adorn the 

 heads of the ladies with these artificial diamonds, by sticking 

 them into their hair ; and a similar custom, as I have before 

 informed you, prevails amongst the ladies of India. 



1 Geoffr. i. 167. De Geer, iv. 35. 



2 I call by this name all those Lampyridce whose head is not at all, or but 

 little, concealed by the shield of the prothorax, and both sexes of which are 

 winged. 



