130 SPECIAL HISTOLOGY. 



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. 1 



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 de- 

 scribed, which, as Froriep and subsequently Brown-Sequard 

 and I have found, contract by electricity, inasmuch as by 

 this means, even in the living subject, the cutis 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 contraction of its circular fibres, 

 and thus protrudes the nipple whose muscular 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 whollv local contractions of 

 the portions of the skin around the hair sacs by which their 

 apertures are protruded conically, is explained simply by the 

 existence of the muscles which I discovered, and which pass 

 obliquely from the superficial part of the cutis down to the 

 hair sacs, and when they act, extrude the sacs, and retract 

 those portions of the skin whence they arise. The assumption 

 of a contractile connective tissue in the skin, as well as in 

 other parts, I must repudiate here, as I have already done 

 (Mittheil. der Zuricher Gesellschaft, 1847, p. 27), because the 

 smooth muscles, which can be microscopically demonstrated in 

 the skin, and whose contraction by galvanism may be experi- 

 mentally shown, sufficiently account for all the contractile 

 phenomena which it exhibits. 



1 [See, however, Wagner's reply to Kolliker, ' Ueber die Tastkorperchen,' in 

 M'uller's 'Archiv,' August, 1852.— Eds.] 



