OF THE SKIN. 131 



more sharply-defined bodies, to which the numerous transverse striae 

 give a certain vague similarity to a fir-cone (Fig. 54). In its more inti- 

 mate structure, such an " axile corpuscle," as I call it, does not con- 

 sist of superimposed discs, as Wagner supposes, but of an internal mass 

 of homogeneous connective tissue, which is most distinct in transverse 

 sections, and when viewed from above ; and of an external generally 

 single layer of undeveloped elastic tissue, which, in the form of fusi- 

 form cells probably connected together and, more or less, drawn out 

 into fine fibres, with shorter or longer nuclei (these last were also seen 

 by Wagner), closely surrounds the internal substance in which here 

 and there similar corpuscles also appear to be contained. Morphologi- 

 cally, then, such a corpuscle is by no means peculiarly constructed, but 

 resembles the axis of certain other papillae (e. g. of the sole of the foot), 

 which are surrounded by true elastic fibres, particularly their often less- 

 developed summits ; it is very similar, again, to the bundles of connec- 

 tive tissue, with elastic fibres wound round them, such as are found in 

 the corium; indeed, the difference consists principally in this, that the 

 axis-corpuscles contain more undeveloped elastic tissue ; a circumstance 

 easily comprehensible, since the papillce, as compared with the cutis 

 itself, consist altogether of a tissue which is in a more embryonic state. 

 With regard to their occurrence, axile corpuscles of the kind here de- 

 scribed occur only in certain papillae ; arid, in fact, so far as my inves- 

 tigations hitherto extend, only in those of the palm and surface of the 

 hand, the red edges of the lips, and the tip of the tongue, not in those 

 of the toes, thorax, back, glans penis, nymphse, and only rarely in those 

 of the back of the hand and of the sole of the foot.* In the hand they 



* [I have recently succeeded in detecting these tactile corpuscles in the toes. They cor- 

 respond exactly to the tactile corpuscles, as described by Wagner and Kolliker in other 

 parts, only they were far less numerous than on the palm of the hand, or on the edges 

 of the lip. I first discovered them in the papillae of the toe of an infant, and have twice 

 since verified my observation. Their minute structure apparently consisted of superim- 

 posed discs, such as described by Wagner. They may be most conveniently studied in fine 

 transverse or perpendicular sections, which have been treated with acetic acid, or a dilute 

 solution of soda. 



The nature of these so-called "tactile"' or "axile" corpuscles is as yet a matter of dispute. 

 Most recent observers seem to entertain regarding them the same views as Kolliker (see 

 Mr. Dalzell's, in the Edinburgh "Monthly Journal of Medical Science," March, 1853; also 

 Mr. Huxley, "Quart. Journal of Micr. Sc.," Oct. 1853, and in Appendix to this work) ; yet 

 Wagner, (in his reply to Kolliker, in "Miiller's Archiv. 1852,'') and more recently Meissner, 

 ("Beitrage Zur Anatomic und Physiologie der Haut," Leipsig,1853) add additional observa- 

 tions in confirmation of the nature of these "corpuscula tactus" as first described by them. 

 Meissner has presented us with some very interesting researches on the relative frequency 

 of their occurrence in the papillae in different parts of the body. Thus he found on a sur- 

 face of 7 lines in length on the lips and apex of the tongue, only 4 or 5 ; on one square 

 line comprising 400 papillae of the last joint of the index finger, 108, but only 40 on the 

 second joint, 18 on the first. In the papillae at the root of the tongue, he was not able to 

 discover any of these bodies. 



The tactile corpuscles are probably surrounded by a special membrane, since they can 

 be isolated. They have as yet only been observed in Man, and in the Ape. DaC.] 



