of the Oil Beetle, Meloe, and of the Strepsiptera. 349 



on its back*." The same gentleman remarks of another species, Halktopha- 

 gus Curtisii, Dale, that it died on the evening of the day on which he captured 

 itf ; and Mr. Halliday states of another, Elenchus Walkeri, Curtis, that the 

 only specimen he could " succeed in bringing home alive he put under a 

 watch-glass, but having left it for an hour, found it dead, though placed in a 

 cool spot|." 



It is thus evident that the life of the imago, in all the species, is a period of 

 the most intense but brief excitement. When on the wing, Mr. Thwaites 

 describes the Stylopes as " exceedingly graceful in their flight, taking long 

 sweeps, as if carried along by a gentle breeze," usually flying high in the air, 

 but " occasionally hovering at a few inches distant from the ground §." Mr. 

 Dale also says of the specimen captured by himself, that " it flew with an undu- 

 latory and vacillating motion" amongst the young shoots of a quickset-hedge 

 in his garden, and that he " could not catch it till it settled on one, when it 

 ran up and down, its wings in motion, and making a considerable buzz or 

 hum, nearly as loud as a Sesia^." These are precisely the habits we might 

 expect to find in an insect that required to seek the object of its solicitude on 

 the wing. But, further than this, Mr. Dale saw another Stylops, confined 

 under a glass in the sun, with a bee, Andrena labialis, from which it had 

 recently been developed, mount on the body of the bee, and remain seated on 

 it, while the latter was in motion, and using every effort to rid itself of the 

 parasite. Further, Dr. Siebold more recently has seen a male of Xenos Rossii 

 mount on the abdomen of a stylopized wasp {PoUistes gallica), and, agitating 

 its wings rapidly, endeavour with much ardour to introduce the extremity of 

 its body between the segments of the body of the wasp, which doubtless con- 

 tained the female Xenos. 



It is fair to infer, then, that this is the mode in which the apodal female 

 Strepsiptera are impregnated while still within the bodies of other insects, as 

 believed by Dr. Siebold ; and that to this great intent of creation every pecu- 

 liarity of structure in the body of the male is to be referred ; thus apparently 

 showing, not only the dependence of function, but even also of special instinct, 

 on peculiarities of structure. The great development of the organs of sense, 



• Curtis's British Entom. fol. 226. t Loc. cit. fol. 433. J Loc. cit. fol. 385. 



§ Trans. Ent. Soc. Lond. vol. iii. part 1. || Curtis's British Entom. fol. 226. 



2 z2 



