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tegument with these sheaths may be seen in sections of the claw with 

 the integument still adhering to it, when on carefully tearing away the 

 latter, its prolongations into the sheaths will be dragged out. That 

 the hairs have some especial and important connexion with the inner 

 vascular and nervous layer of the integument of the lobster's claw and 

 elsewhere, seems probable from the observations made by the author 

 on the contents of the claw. The terminal moveable piece, the pollex, 

 and the prolongation of the metatarsus which it opposes, the index, 

 do not contain muscular fibre, but are filled entirely by a soft pulpy 

 mass of corium. The nerves of the limb are large, but only some 

 small branches will be found to go to the muscles ; the principal nerves 

 pass on and terminate in the pulp which fills the opposing pieces of 

 the claw. The author believes that it is the office of the hairs to 

 establish a communication between the outer surface and this inner, 

 and no doubt highly sensitive pulp,- and that this is rendered still 

 further probable by the comparison of the claws on the two sides. 

 In the smaller claw the edges are sharp, and have fine tubercles 

 along their margin ; and the hairs are placed in a regular series of 

 short tufts on each side of the tubercles, beyond which they do not 

 project. But on the larger crushing claw, the tubercles are massive, 

 and no hairs are seen projecting above the surface. If, however, a 

 section be made, it will be seen that a communication is esta- 

 blished between the inner pulp and the surface by means of an abun- 

 dant series of canals which terminate in bulbous extremities, sometimes 

 projecting beyond the surface, sometimes lodged in depressions in the 

 shell. This arrangement may be found in other parts ; and in the 

 crab's claw, where the tubercles are deficient, these hairless pulp- 

 cavities almost entirely replace the hairs. 



Here, then, lodged within the densest part of the shell, is a struc- 

 ture richly supplied with nerves, shut off from other parts of the 

 body, and having communication with the surface only through the 

 medium of canals, which are sometimes continued into short bristles, 

 and sometimes terminate in mere bulbs. As a prehensile organ, the 

 claw needs sensibility, but no force which the animal could exercise 

 could make any impression on the parts within, through its dense 

 tuberculated edges. On the other hand, it is difficult to assign any 

 office to the bristles, and still more to the bulbs, mechanical or 

 otherwise, unless it be that which has been suggested, that, establish- 



