130 SPECIAL HISTOLOGY. 



which the relations of the nerves of the skin have hitherto been entirely 

 misconceived. From the investigations of G. Meissner and himself, 

 which were instituted upon the nerves of the palm of the hand, Wagner 

 divides the papillce into nervous and vascular. The former are said to 

 contain a peculiar oval corpuscle in their axis, which consists of super- 

 imposed saccular or band-like laminae, resembling a fir-cone, and this 

 structure is regarded by Wagner, as a peculiar sensory apparatus, and 

 named by him " tactile corpuscle" (corpusculum tactus). Into these 

 the nerves 1 to 3 fine dark-bordered tubules are said to enter from 

 below, or from the side, and to terminate within them, either free, or 

 perhaps divided into many delicate branches. Wagner found these 

 corpuscles to be most abundant in the points of the fingers, and that 

 they were more and more rare towards the wrist. I have considered 

 it requisite to investigate these assertions, which are made with much 

 confidence, particularly as Wagner grounds upon them great expecta- 

 tions of the physiology of the sense of touch, and the following are the 

 results at which I have arrived. 



Independently of the vessels and nerves, the papillae consist, in the 

 main, of a sometimes more homogeneous, sometimes more distinctly 

 fibrillated collagenous substance, which there is no reason to distinguish 

 from connective tissue, and of fine elastic fibres in different stages of 

 development, as fusiform cells (corpuscles of the connective tissue, of 

 Virchow), cell networks, isolated fine elastic fibres and fibrous networks. 

 These elements are so distributed, that in most papillce a cortical layer 

 and an axile tract can be distinguished. In the former the fibrous 

 elements are disposed longitudinally, and the connective tissue is often 

 distinctly fibrillated, with the exception of the most superficial layer, 

 which forms a clear, homogeneous but not separable margin. In the 

 latter, on the other hand, the substance is more uniform and clear, and 

 in many places is separated from the outer layer by transverse elastic 

 fibres. When these latter, true elastic fibres, are not very closely dis- 

 posed, no one would be led to consider that there is anything peculiar 

 in this arrangement ; but undeveloped and very close together, as they 

 are in Wagner's corpuscle, it is otherwise. These are, in fact nothing 

 but the clear axis marked by transverse nuclei and nucleated fibres, 

 which I have already described ; and, if no reagents be added, they pre- 

 sent no other appearance than that which I have figured in my "Micro- 

 scopic Anatomy," Fig. 4, or in Fig. 48 of this work. 



Dilute solution of soda, of which almost solely I have availed myself 

 in investigating the course of the nerves in the papillae, often does not 

 render their contour at all more distinct, and I therefore paid no fur- 

 ther attention to their structure ; while, on the Other hand, acetic acid, 

 which was also employed by Wagner and Meissner, brings out the axes 

 of the papillae generally, though not always, as oval, or cylindrical, 



