344 LEIEBVRE ON MANTIS. 



do not present this striking disproportion, it would seem that 

 these etiolated specimens have not been placed (like their 

 allied species), at the period of their transformation from the 

 pupa to the perfect state, in circumstances so favourable to the 

 development of their organs of flight, but nevertheless they 

 have just as much arrived at maturity. It must, however, be 

 remarked that this imperfect organization appears more per- 

 ceptible in the wings than in the elytra, inasmuch as they are 

 merely rudiments, scarcely differing from what they were in 

 the pupa state ; whilst the elytra, though still etiolated, yet 

 much larger than the wings, hide a part of the thorax, and 

 possess the form and characters they would have assumed if 

 yet further developed. 



In calling attention to this abortive state, I have been in- 

 duced to class together those species in which it is apparent, 

 that it may be understood as regards the size of these parts, 

 they may be met with much better developed ; and consequently 

 what I have said is susceptible of modification according to 

 their dimensions. 



It is extremely difficult to fix the precise time when the 

 wings and elytra in Orthoptera, (but especially in certain 

 groups,) attain their full size ; for few insects in their last state 

 afford such variety in their organs of flight, and that too in 

 specimens unquestionably of the same genus, and which seem 

 so nearly allied, that the knowledge we possess of the normal 

 size of these parts in certain species would favour the opinion 

 with respect to others of the same genus, that though appa- 

 rently more or less abortive, their alary organs had attained 

 their perfect state. 



In fact, in a new species nothing is more difficult than to 

 define the standard size, if the wings and elytra have not ac- 

 quired that expansion which the allied species indicate. But 

 though these organs may be a little scanty, it does not follow 

 that they must always remain so, or that they are incapable of 

 expansion, if, at its last change, the insect were placed in 

 circumstances favourable to their development. Here is a 

 difficulty: for in some well-known species we have sometimes 

 large elytra and small wings, and vice versa ; in others, again, 

 we find merely the rudiments of both organs, which would 

 lead one to suppose that their imperfection was no deviation 

 from the intention of nature: — I will cite, amongst others, a 



