EXTERNAL ANATOMY OF INSECTS. 591 



cumstance, and upon which a theory may be built. In 

 some insects the primary and secondary wings or their 

 analogues are placed before the legs, in others over the 

 legs, and in others behind the legs : but whatever their 

 position, the pieces which I have named the scapularia 

 and parapleural invariably connect the one with the 

 other : the former, the primary wings with the mid-legs, 

 and the latter, the secondary wings with the hind-legs. 

 This circumstance seems to prove that the wings by the 

 intervention of these pieces have an action upon the legs, 

 and the legs upon the wings ; and this is further proved 

 in one case by an observation of M. Chabrier with re- 

 gard to Melolontha vulgaris, — that the levator muscles of 

 the wings, by means of a long tendon, are attached to 

 the lower part of the posterior coxae a . Now, more than 

 one medical friend has suggested to me, that what are 

 called the coxa in insects are really analogous to the 

 thighs of vertebrate animals b : consequently these parts 

 must represent the coxae ; whence it would seem that the 

 wings are really appendages of the legs. It must, how- 

 ever, be observed, that were this opinion admitted, in the 

 Apt era, Hymenoptera, and Dipt era, or even in the pro- 

 thorax of other insects, there would scarcely be any ana- 

 logue of the coxa at all distinct from the trunk itself, of 

 which even in the other Orders these pieces are com- 

 ponent parts. An instance occurs in the Strepsiptera K., 

 and in which the arms are furnished with an alary ap- 

 pendage, and the metathorax has none c . 



a Ubi supr. c. ii. 333. 



b According to M. Chabrier, who agrees with him, M. Latreille 

 also is of opinion, that the parapleura is the analogue of the poste- 

 rior cox<e. Ubi supra, c. ii. 312. Note 2. 



c M. Latreille has changed the denomination of this Order to 



