138 SPECIAL HISTOLOGY. 



nations of the nerves in the skin, can hardly be doubted ; but, on the 

 other hand, there is no obvious reason, a priori, why peculiar hitherto 

 unknown organs should exist to that end ; nor why the condition to 

 which I have already referred, the more isolated course of the fibres of 

 the nervous tubules in the papillae and terminal plexuses, their fineness, 

 superficial position, and the delicacy or absence of the neurilemma, may 

 not abundantly suffice as an explanation. That Wagner's so-called cor- 

 puscula tactus, my axile corpuscles, are not tactile organs in the sense 

 intended by Weber, is easily demonstrable. Independently of the erro- 

 neousness of his views of their structure, and of the fact that the nerves 

 are not distributed in them, but only proceed along them, outside, in 

 order, in many cases, to terminate even beyond them we find that all 

 the essential functions of the skin are also performed without such cor- 

 puscles. The feeling of warmth and cold, of orgasm, of tickling, of 

 pressure, of pricking, of burning, of pain, are found partly over the 

 whole surface of skin, partly in places where these corpuscles are cer- 

 tainly absent, which sufficiently shows that they have not in the remotest 

 degree the signification ascribed to them by Wagner. However, it is not 

 likely that they exist for nothing in those particular localities, in which 

 the sensibility to pressure is the greatest, and which we use especially 

 as tactile organs, as the ends of the fingers, the point of the tongue, and 

 the border of the lips ; and I consider them as parts, which in conse- 

 quence of their being composed principally of dense, imperfectly -formed 

 elastic tissue, confer a certain solidity upon the points of the papillae, 

 and serve as a firm support for the nerves, in consequence of which, a 

 pressure, which in other situations is not sufficient to affect the nerve, 

 here takes effect. They would, in fact, be organs, like the nails and 

 phalangeal bones, not essential and indispensable to the sense of touch, 

 but only conferring upon it a greater acuteness than elsewhere. If, in 

 this sense, they are to be called tactile corpuscles, I have nothing to say 

 against the term, but then the phalanges and the nails, the " whiskers" 

 of animals, &c., equally deserve the name of tactile organs. 



The contractility of the skin is exhibited in the wrinkling of the 

 scrotum and of the skin of the penis, the erection of the nipple, and the 

 occurrence of the so-called cutis anserina. It depends upon the smooth 

 muscles of the skin already described, which, as Froriep and subse- 

 quently Brown-Sequard and I have found, contract by electricity, inas- 

 much as by this means, even in the living subject, the cut-is anserina, 

 the erection of the nipple, and, in recently-executed persons, a wrinkling 

 of the scrotum can be produced. In the erection of the nipple by gentle 

 mechanical irritation, the whole areola becomes diminished by the con- 

 traction of its circular fibres, and thus protrudes the nipple whose mus- 

 cular fibres, in this case, seem to be relaxed. Cold causes the areola 

 and the nipple to contract, both becoming small and firm. The cutis 

 anserina, which consists in wholly local contractions of the portions of 



