520 Dr. G. Thin on the Anatomy of 



the plates that illustrate works on this subject, although the influence 

 of Yon Eecklinghausen's doctrine (namely, that wherever an epithelium 

 is found a lymphatic capillary must be supposed to exist) has led to what 

 I believe to be their true nature being overlooked. 



From a similar cause to that encountered in tendon, the complete re- 

 duction of the dense corium of mammals by potash is very difficult ; but 

 by treating thin sections of fresh cutis, isolated flat cells are found. 



In the cutis of the frog, the bundles of fibrillary tissue are arranged in 

 parallel layers, and the corium being thin, the demonstration of flat cells 

 is easier. And here the continuity of these cells with those of the rete 

 Malpighi is evident, in the same way as the cells of the anterior epithe- 

 lium of the cornea are continuous with the flat cells of the interior of 

 the structure. 



Figures 11 and 12, Plate X., represent flat cells from the skin of the 

 ox and frog. 



I make the same inference in regard to the communication of the 

 spaces between the cells of the rete Malpighi with the lymph-spaces of 

 the corium, that I make in regard to the similar arrangement in the cornea, 

 both as regards anatomical continuity and in regard to the position of 

 the nerves in the spaces. Langerhans has described the network of 

 nerve-fibres in the rete Malpighi, and, in that of the cutis of the rabbit, 

 the rich network in the spaces between the cells is not very difficult to 

 demonstrate. In the skin of the finger, I have traced a medullated nerve 

 as high as the third layer. 



Banvier, in that part of his essay which treats of the elements cellu- 

 laires du tissu conjonctif Idche, describes an entirely different anatomical 

 element from that on which the authorities with whom he is in contro- 

 versy had fixed their attention. The cells figured by him* are the same 

 as those isolated by potash when very thin pieces of skin or areolar tissue 

 are operated on. As described by him, they are applied closely to the 

 bundles. But when he attempts to show that the connective-tissue cor- 

 puscle of Virchow does not exist, and that the appearances by which it is 

 distinguished depend on an optical delusion, I believe him to be mistaken. 

 In skin and subcutaneous tissue the chloride of gold brings out in the 

 clearest manner the existence of nucleated cells with long projecting pro- 

 cesses stretching between and around the bundles, the whole of the 

 cells being connected by the anastomoses of their processes. So com- 

 plete is the analogy between skin and tendon, that it would be easy to 

 find parts of a successful gold preparation of skin where the diagnosis 

 between skin and tendon might be difficult. 



Figures 13 and 14, Plate X., illustrate the appearances presented by 

 the branched cells in skin. 



A history of the opinions held regarding the structure of the con- 

 nective tissues since the time of Schwann is equally beyond the scope of 



* L, c. p. 483, 



