INNERVATION OF INTEGUMENT OF CHIROPTERA 321 



3. Special sensory end-organs 



The literature dealing with special sensory end-organs in 

 general has recently been reviewed by a number of investigators : 

 Szymonowicz ('95), Trejakoff ('02), Dogiel ('03), Schafer ('10). 

 Therefore only a brief survey of the observations upon such end- 

 organs in the skin of bats will be given here. 



Arnstein ('76) found in the flying membrane of a bat an end- 

 bulb which he thought resembled the well known cylindrical end- 

 bulb of Krause. It was possible for him to trace an axis cylinder 

 into the organ, but he was unable to make out the ending of 

 the fiber. In one instance, however, he saw it break up into fine 

 fibrils. Arnstein was of the opinion that these end-bulbs occurred 

 in the flying membrane where no hairs were present. 



Schumacher, in 1907, mentioned the presence of a large num- 

 ber of layer-like corpuscles ('Lamellenkorperchen') among the 

 phalanges. 



Sabussow ('10) investigated the flying membrane of two 

 species of bats (Vesperugo noctula and Vespertiho daubentonii) . 

 He stated that in weakly stained preparations he could see ter- 

 minal bulbs which were divisible into two classes according to 

 size. Some were so small that upon shght magnification it was 

 difficult to see them; others were comparatively large, had a 

 zigzag course, and could be recognized with ease. The latter 

 could also be seen in material prepared by Apathy's after-gilding 

 gold chloride method. The general characteristics peculiar to 

 all end-bulbs which Sabussow observed were: (1) a longitudi- 

 nal course of the fibers of the enveloping connective tissue mem- 

 branes, apparent in gold preparations, and (2) a delicate wavy 

 appearance of these membranes seen in methylene blue material. 

 The connective tissue nuclei did not stain in methylene blue 

 preparations, but on account of the difference of refraction, 

 Sabussow thought that by focusing he could see them. He 

 noted that the core of the bulb was narrow, but was unable to 

 make out its finer structure. 



The consideration that led Sabussow to classify these struc- 

 tures under the cylindrical t^-pe of end-bulbs was chiefly the 



