204 LANGDON. [Vol. XI. 



rounded by a black deposit ; secondly by the fact that they 

 may be traced into the central nervous system. 



Both cross and longitudinal sections show that these fibres 

 pass between the epidermal cells from the basement-membrane 

 almost or quite to the cuticula. Some of the fibres are simple, 

 some branch one or more times. It is hard to decide definitely 

 as to their ultimate endings. Some become very slender and 

 seem to end freely between the cell walls at varying distances 

 below the cuticula ; most of the fibres pass almost to the cuti- 

 cula, where their ends are lost in the black deposit which is 

 usually found there. The fibres vary in diameter and depth of 

 stain ; they are sometimes straight and of uniform caliber, but 

 usually a little sinuous and varicose. In a few cases the upper 

 end was found to turn at right angles and to run for a short 

 distance just beneath the cuticula, sometimes again turning 

 and running a very short distance toward the basement-mem- 

 brane. There is sometimes found an appearance which sug- 

 gests an anastomosis of these fibres in the epidermis (PI. XIII, 

 Fig. 5). A careful study shows that, in such cases, the fibres 

 merely cross one another. 



Sometimes in the basement-membrane, sometimes among 

 the cells of the basal layer of the epidermis, are larger and 

 more deeply stained fibres. In sections which pass obliquely 

 through the epidermis, it is easy to see that the fibres between 

 the epidermal cells arise from these fibres which pass along 

 the base of the epidermis. It is not difficult to find places in 

 cross sections in which the same fact is clearly shown (PI. XIII, 

 Figs. 3 and 6). These epidermal fibres often appear, at first 

 sight, to be connected with the basal processes of the support- 

 ing cells, but a careful study shows that in every such case the 

 fibres really run under or over these processes. Sections pass- 

 ing obliquely or tangentially through the base of the epi- 

 dermis show that these subepidermal fibres form a freely 

 branching network (PI. XIII, F'igs. 8, 9). The fibres of this net- 

 work often appear to anastomose, but careful focusing shows 

 that in the greater number of such cases the fibres merely 

 cross each other. In a smaller number of such cases there 

 seems to be a real anastomosis (PI. XIII, Fig. 9, a). 



