ON THE SERRICORNES. 36l 



of position ; by this movement the long spine issues entirely 

 out of the oval hole in which it is lodged. At the same 

 time it always applies its feet against the under part of the 

 body, and holds them fast there, and crowded together, 

 which secures them from the dangers of the fall. After- 

 wards, approximating the corslet to the breast, it pushes 

 strongly and rapidly against the edge of the hole, the long 

 point, which falls back like a spring in re-entering its cavity. 

 The corslet with its lateral points, the head, and even the 

 upper part of the elytra, all coming with force against the 

 plain of position, also concur by their elasticity, to raise the 

 body into the air. By holding the insect by the belly be- 

 tween the fingers, one may easily convince himself of the 

 exactness of these observations. The more the plan of posi- 

 tion is firm and hard, the greater will be the elevation of the 

 leap. It has been also remarked that the insect rests the two 

 lateral spines of the corslet against the inferior edge of the 

 elytra, and that it relaxes them at the same time that it 

 causes the long point to re-enter the whole, which operation 

 is very capable of augmenting the elastic force which carries 

 it upwards. It is necessary that the corslet should have a 

 movement, and free play upon the breast ; accordingly it is 

 very mobile, and the insect can lower it considerably. 



By pressing the belly of the male between the fingers, 

 three parts are made to come out, of which those of the 

 sides serve as a case to that of the middle, and are concave 

 anteriorly. In their natural situation these three parts are 

 enclosed in a second case, which opens towards the sides, 

 and which is supported by two concave scaly lamina?, form- 

 ing a third case. The elongated portion of the middle is 

 doubtless that which characterizes the sex of the male. From 

 the belly of the female, by the same pressure, parts totally 

 different are made to come out. This is a long, cylindrical 

 piece, at the end of which are found two other elongated 



