30 BEES AND BEE-KEEPING. 



part of their bodies, by a layer of secreting cells, 

 called the hypodermis, an external skeleton, com- 

 posed of a remarkable substance, to which the name 

 Chitine has been given. Chitine is capable of 

 being moulded into almost every conceivable shape 

 and appearance. It forms the hard back of the 

 repulsive cockroach, the beautiful scale-like feathers 

 of the gaudy butterfly, the delicate membrane which 

 supports the lace-wing in mid air, the transparent 

 cornea covering the eyes of all insects, the almost 

 impalpable films cast by the moulting larvae, and the 

 black and yellow rings of our native and imported 

 bees, besides internal braces, tendons, membranes, and 

 ducts innumerable. The external skeleton, hard for the 

 most part, and varied in thickness in beautiful adap- 

 tation to the strain to which it may be exposed, gives 

 persistency of form to the little wearer ; but it needs, 

 wherever movement is necessary, to have delicate 

 extensions joining the edges of its unyielding plates. 

 This we may understand by examining the legs of 

 a lobster or crab, furnished, like those of the bee, 

 with a shelly case, but so large that no magnifying- 

 glass is required. Here we see that the thick coat 

 is reduced to a thin and easily creased membrane, 

 where, by flexion, one part is made to pass over the 

 other. Likewise, in the antennae of the bee (a, Plate II.), 

 the insertion into the head, by a sort of ball and 

 socket joint, covered by chitine so thin and transparent 

 that nerves may be seen through it, admits of the 

 varied movements proper to this instrument of inter- 

 communication; for it is hardly too much to say that, by 

 means of the antennas, the intelligent little creatures talk. 



