324 JAMES EDWARD ACKERT 



of the axis cylinder appears pointed or hooked, according to 

 the position of the nerve when cut. The connective tissue nuclei, 

 which did not stain in methylene blue, but which Sabussow 

 thought he could make out by focusing, are in the opinion of the 

 writer nuclei of the sheaths of Schwann or of the perineurium. 



In the present investigation no gold chloride method was 

 used, but material prepared by the Cajal silver nitrate method, 

 Bielschowsky's method, or with methylene blue counter-stained 

 with carm.alum, has failed so far to reveal the presence of this 

 second type of 'end-bulb' as described by Sabussow. 



b. Terminal corpuscles. These comparatively large spheroidal 

 corpuscles are found in the stratum reticulare of the corium, 

 usually at some distance beneath the lower level of the hair fol- 

 hcles. In methylene blue preparations they stain deeply, ex- 

 hibiting a cellular appearance, and frequently showing one or 

 more nuclei (figs. 19, 20). Their size, which is fairly constant, 

 is approximately 20m in length by lO/x in width. Each corpuscle 

 is innervated by a medullated fiber which arises from the second 

 nerve layer. The fiber passes into the deeper part of the corium, 

 and after giving off a few branches, enters the corpuscle, where it 

 disappears among the cells. Occasionally, the fiber, on approach- 

 ing the organ in question, forms a shght spiral coil (fig. 19). 

 Thus far it has been impossible to trace the course of the nerve 

 fiber within the corpuscle. To estabhsh the identity of these 

 organs with any of the known types of corpuscles is difficult. 

 The layer-like capsules characteristic of Pacinian corpuscles are 

 not apparent, but their absence may be due to incomplete stain- 

 ing. They more nearly approach the size of the type in question 

 than that of any other type of corpuscles commonly found in the 

 mammalian skin. Their location is identical with that of Pacin- 

 ian corpuscles. From the fact set forth it seems possible that 

 these spheroidal, cellular bodies may be Pacinian corpuscles. 



To these two types of sensory end-organs may be added ter- 

 minal varicosities, which are abundant in the region of hair 

 follicles, outside of the root sheaths. Comparatively strong 

 nerve fibers can be seen to enter these structures, where they 

 break up into fine fibrils, and are surrounded by neuroplasm. It 



