12 S. B, VINCENT 



For the most part these nerves terminate in a one-layer mantle 

 of touch cells all over the follicle in the Malpighian layer of 

 the outer root sheath, but the endings are the largest and most 

 characteristically developed over the superior swelling of the 

 sheath (a, fig. 9). The large nerves preserve their myelin almost 

 to the very end, when they suddenly go over into disc-like expan- 

 sions of various sizes — ^leaf-like endings with thread-like stalks. 

 The whole appearance is as if the sheath were flattened out very 

 thin to furnish a support for the intertwined neuro-fibrils (fig. 11). 

 At times there is just one of these leaf-like endings, again there 

 may be^two, three or four. When there is more than one, each 

 member is connected with the preceding by a deeply stained 

 fiber which arises from the corner or tip of the expansion and 

 the whole series has a somewhat definite arrangement. I have 

 often seen follicles which looked as if they were surrounded by 

 horizontal or oblique running bands of these menisques. They 

 have been well described by Cajal ('09, p. 474): 



They show in the interior a fine network of neurofibrils separated by 

 an abundant uncolored neuroplasm. This network is of the same com- 

 position as that of the body of the nerve cells. We find first, the large 

 neurofibrils frequently bending and forming the framework of the ter- 

 mination and second, pale fine fibrils which bind together all the others. 

 A large number of menisques are supplied by one nerve fiber. 



The cells between which or under which these menisques lie 

 are large ovoid cells, probably modified Malpighian cells of the 

 'outer root sheath. There is no connection to be seen between 

 the cell and the fibrillar plexus of the menisques. What has 

 happened is this: The nerve has lost its myelin and one of the 

 fine fibers described before has pierced the glassy layer and 

 expanded within under one of the large cells found here. The 

 glassy layer is very thin over the superior swelling and disappears 

 above it. As it is very dense and hard to perforate elsewhere, 

 the greater number and size of the endings found at this place is 

 accounted for. Yet fibers do push through at lower levels also. 



There has been a great deal of discussion as to the relative 

 position of these menisques with regard to the cell body and to 

 the axis of the hair. In the rat" there seems to be no one char- 



