ON THE PALPICORNES. 443 



head of which is inclined under the corslet, and its abdomen 

 a little curved, is supported in this lodge only by means of 

 these various appendages. No other part is in contact with 

 the interior parietes of its dwelling, which circumstance, ac- 

 cording to M. Miger, preserves it from an injurious degree 

 of humidity. If this nymph be turned on the back or side, 

 it soon re-establishes itself in its natural position, by the 

 movements of the rings of its body. But it does so with 

 difficulty in a cavity of a different curve. 



The nymph state endures about three weeks, during which 

 the corneous parts become coloured by little and little. 

 Turned upon its back, and causing its feet and the rings of 

 its body to move, the insect contrives to disengage itself from 

 its envelope, which was at first cleft at its superior part. 

 The elytra being applied under the belly, go and place them- 

 selves over the back ; the wings are unfolded and remain ex- 

 tended, until they have acquired a certain degree of consis- 

 tence. The insect soon draws them under the cases, which 

 are still white and soft, and places itself upon its feet, which 

 are as yet but infirm. At the end of twenty-four hours it 

 has acquired the brown colour which is proper to it ; but it 

 still remains for twelve days in the earth, and without mov- 

 ing. When this period has elapsed, it has acquired all its 

 strength. The flexibility of its elytra, the compressibility 

 of its body, and the play of its other external organs, impart 

 to it the means of breaking its prison. It escapes through 

 a very small aperture. According to the very interesting 

 observations of M. Miger, the total duration of these meta- 

 morphoses, beginning with the oviposition, is about ninety- 

 eight days ; of this number the insect has passed sixty days 

 in the larva form. 



According to this skilfid naturalist, the larvse of the hy- 

 drophili are of two kinds. The first, which he designates 

 under the name of swimmers, (nageuses;) have near the res- 



