204 Analyses of Booh. [March, 



which, in common with many other insects, it assumes when 

 suddenly disturbed. This stratagem, for so it may be called, 

 appears to be most decidedly practised by the animal while in 

 captivity ; and if thrown at random out of the vessel in which it 

 has been confined, however unnatural the posture may be into 

 which it has been thrown, it remains as it were in a state of 

 catalepsy during half a minute or more : the first indication 

 which it gives of recovery from this stupor, invariably consists 

 in a motion of the extremity of the antenna. 



" The general colour of the insect is a dusky brown, passing 

 either into a reddish brown, or into an ochry yellow ; those 

 parts being of the darkest colour which are most exposed to 

 view when the animal is moving in the open air. Every part of 

 the body is to a greater or less degree covered by a kind of 

 down, which seems to be the efficient cause of its capabihty 

 of repelling moisture ; which capabihty is so remarkable, that 

 when the insect is plunged under water, it appears as if cased in 

 silver, or some bright metallic covering ; this appearance being 

 evidently derived from a stratum of air, interposed between its 

 body and the surrounding liquid. This down not only serves to 

 repel the adhesion of any moist substance to its body, but also 

 facilitates tke motion of the animal, by lessening the degree of 

 friction which would otherwise take place ; and it is owing to 

 the same circumstance that there is an unusual degree of diffi- 

 culty in retaining a sure hold of the insect, even when dead ; 

 but more especially when alive, and struggling against deten- 

 tion. The degree of force which it commonly exerts on such 

 occasions is very remarkable ; and, from the sensation produced, 

 may easily be supposed to be what Rosel says it is, equal to the 

 counterpoise of two or three pounds. The skin or covering of 

 the insect is in some parts nothing more than a thin membrane ; 

 in other parts it resembles soft leather ; and sometimes equals 

 horn or even shell in its degree of hardness." 



Head. Upper part and sides a thick, hard, horny case, con- 

 taining the motor muscles of the jaws : in order to strengthen it, 

 two firm bars run transversely across the bottom both of the 

 anterior and posterior margin, which are united by a still stronger 

 bar running longitudinally from the middle of the one to that of 

 the other. 



" The antennae, which are situated near the articulation of 

 the mandibles, consist of a great number of minute segments ; 

 resembling beads of a circular form : the number of these beads, 

 which varies in different instances, is usually from 100 to 110; 

 rarely more or less: but it is worth noticing that in examining 

 the two antennae of the same individual, I sometimes found the 

 number of beads greater in one than in the other ; and as the 

 terminal bead difiisrs in its form from all the rest, the result of 

 the examination is less open to doubt than it would otherwise 

 have been. Each bead is united to the one that precedes and 



