316 JAMES EDWARD ACKERT 



Observations made by different investigators on the inner- 

 vation of the hairs of bats have been so conflicting that it seems 

 advisable to give a brief review of the literature. Schobl (71) 

 studied the innervation of the hair of the flying membrane, and 

 set forth the following principal points: In the hairs of the bat, 

 the nerves terminate in special corpuscles ('Terminalkorperchen') 

 situated at the bases of the hair follicles. The hair receives a 

 bundle of nerves which consists of from two to five medullated 

 fibers. These twist many times in a spiral about the hair shaft 

 forming a nerve wreath or ring. From this spiral ring two to 

 four nerve fibers are given off, and these extend downward, end- 

 ing in the terminal corpuscle beneath the hair follicle. A super- 

 ficial nerve ring which consists of from one to two coils is formed 

 by fibers from the fourth nerve layer. ^ Boll ('71), working on 

 similar material, confirmed Schobl's observations. 



The following year Stieda took exception to Schobl's account, 

 especially in regard to his 'Terminalkorperchen.' This observer 

 concluded that the structure in question was not a nervous 

 apparatus but rather a differentiated part of the hair folhcle 

 ('Haarkeime'). The nerve ring was not mentioned by Stieda. 

 Beil ('71) also denied the existence of Schdbl's end-corpuscles, 

 although he was able to see the nerve ring. Concerning the 

 structure of the latter, its course, or the endings of its fibers, he 

 could determine nothing definitely. Above the sebaceous glands, 

 however, Beil noted the entrance t>f two or three bundles of non- 

 medullated nerves into the hair follicle. 



Using the method described by Schobl himself, Veleeky ('72), 

 investigating the flying membrane, likewise did not find the so- 

 called end-apparatus; nor did the use of gold disclose these 

 'Terminalkorperchen.' By the latter method, however, he dem- 

 onstrated non-medullated nerves which approach, from below, 

 the cells of the epithelium of the outer root sheath of the hair, 

 and spread into the intercellular spaces, forming a net. 



In the same year appeared a more important piece of work by 

 Jobert, in which he described in considerable detail the inner- 

 vation of the hair of the bat's wing. The principal points brought 

 out were as follows: (1) All the hairs of the skin are supplied 



