582 DR9. Q-EORGE AITO FRAKCES E. HOGaAN ON 



epidermic fibrils or free endings in every stage of growth. 

 Sometimes these fibrils 'are single and pass perpendicularly 

 through the e|)idermis, until on reaching the inert layers near 

 the surface they may divide into several branches, and then 

 crumble away into fragments. At other times (and this gives 

 the key to the whole question) they may form a loop or arch, the 

 columns of which rest upon or are continuous (as in fig. 19, 

 Plate XV.) with two or more of the cells forming the ganglionic 

 group lying upon the lower surface of the epidermic interpapil- 

 lary downgrowth, showing that the so-called terminal nerve- 

 cells belong to the same nerve-system as the intraepidermic 

 nerves. Next to the important fact that they are so connected, 

 comes the question of how the fibres come to lie throughout the 

 epidermis. This we think we are able to explain, and in doing 

 so to describe a new power, hitherto unrecognized, but whose 

 existence will account for other phenomena connected with the 

 nervous system, to which we shall also call attention. 



"First, let it be understood that the branched nerve-cells we 

 are now considering are often found in large numbers forming 

 groups at various localities and depths in the dermis, and that 

 they appear to grow up upon, or are prolonged with the nerve- 

 fibres, generally non-medullated, to which they are attached. 

 The conditions of their presence there, however, seem to be very 

 variable, as if the groups made their appearance there by fits 

 and starts ; for in two contiguous localities in the skin of the 

 same animal one may be full of these cells and the other destitute 

 of them. When found, however, they are seen to be evidently 

 growing up towards the epidermis. There they become arrested, 

 either on the lower surface of the epidermic interpapillary 

 downgrowths or within the papillae themselves, which sometimes 

 become stuffed full of such cells. In fact, the cells collect 

 against any obstruction as drift-rubbish collects before a grating 

 on a stream. So closely do the cells apply themselves to the 

 lower surface of the epidermis, that they become flattened and 

 show a slight concavity towards the free surface of the skin. At 

 other times they get jammed between the epidermic cells, more 

 especially on the sides of the dermic papillae, so that, when cut 

 through in perpendicular section, they appear quite narrow and 

 elongated. 



In fig. 19, Plate XY., we have a group or ganglion of such 

 cells flattened against the lower surface of the epidermis, the 



