286 ON THE CORPUSCULA TACTUS 



2. Everything I have seen leads me to believe with Kolliker, that 

 the ' corpuscle ' is not histologically, in any respect, a special structure, 

 but merely rudimentary connective tissue (areolated embryonic con- 

 nective tissue of Kolliker), exactly resembling that which is to be 

 found in the rest of the papilla. This consists in fact of a homo- 

 geneous matrix in which endoplasts (nuclei) are embedded, and 

 which, in various directions surrounding and radiating from these, is 

 metamorphosed into a substance more or less resembling elastic fibre. 

 The sole difference from the surrounding substance presented by the 

 corpuscle consists in this, that these elastic bands and filaments are 

 more or less parallel to one another, and perpendicular to the axis of 

 the corpuscle (fig. i). 



In one respect, however, I believe that the corpuscles are peculiar, 

 and something more than the mere, imperfectly formed axis of the 

 papilla. Kolliker has pointed out (/. c. p. 67) that the nerve-tubules 

 which enter the papilla are accompanied by a delicate neurilemma, 

 and I believe that the " corpuscles " are its continuation and termina- 

 tion. In structure, the neurilemma which surrounds the more delicate 

 branches of the nerves in the human finger (fig. 7) is identical with 

 the " corpuscles,'' except that in the former the elastic element is 

 disposed parallel with the nerve fibre, while in the latter it is more or 

 less perpendicular to it. In fact, I believe, that the " corpuscle " is 

 simply the modified extremity of the neurilemma of the nervous 

 tubules which enter the papillse. 



3. With respect to the extremely difficult question of the mode of 

 termination of the nerves, I may state that, without having any 

 reason to urge against the existence of loops (on the contrary, having 

 observed them very distinctly in the cutaneous papillje of fishes), I 

 have never been able to convince myself of their presence, and fre- 

 quently when I believed I had such cases before my eyes, the use of 

 a higher power, or the causing the papilla to turn a little, would 

 undeceive me. 



On the other hand, it is by no means difficult to obtain the clearest 

 possible evidence of the occurrence of the so-called free ends (figs. 3, 

 4, 5). The dark-contoured fibres pass, sometimes only a little beyond 

 the proximal extremity of the corpuscle (figs. 4, 5), sometimes quite 

 to its distal end (fig. 3), and here terminate by one or two pointed 

 extremities, which appear to be continuous with the tissue of the 

 corpuscle. I have never been able to obtain any evidence of the 

 entrance of a dark-contoured nerve fibre into a " corpuscle.'' My 

 belief that the nerves in the corpusculated papillae of Man do reallj^ 

 terminate in this manner, is strengthened by the ease with which this 



