PAIRING OF INSECTS. 



211 



serve, however, that there are a few remarkable ex- 

 ceptions to this o-eneral rule, in the same way as, 

 among-st birds of prey (Raptores,yiGORs), the greater 

 size of the female is an exception to the general rale 

 of the male of birds and quadriipeds being the largest. 

 According to this latter rule, then, and of course an 

 exception amongst insects, we may mention the 

 dragon-flies {Libellulina), whose females are often a 

 little smaller, and never larger, than the males, as 

 is also the case with the water-spider {Argyronda 

 aquatica, Walck.). But the most remarkable in- 

 stance of this occurs in the stag-beetle {Lucanus 

 cervus), so common in Kent and some other dis- 

 tricts, though rare, or unknown, in the greater part 

 of the empire. The size, however, is not the only 

 distinction ; for the female possesses little more than 



Male and female stag-beetle. 



the rudiments of the very remarkable horn-like man- 

 dibles with which the male is furnished. This organ 



