INNERVATION OF INTEGUMENT OF CHIROPTERA 323 



(fig. 18, en). The deeply stained blue plate stands out in bold 

 contrast to the weakly colored bulb about it. The distal branch 

 arising from the thickened axis cylinder usually bends to one 

 side, breaks up into an irregular, elongate, granular mass, and 

 as such extends back through the expanded part of the bulb 

 (fig. 18, hr). In the portions of the organ surrounding the plate 

 and the recurrent granular mass no layers nor nuclei are visible. 

 With the exception of the lack of nuclei the appearance of this 

 end-bulb is practically identical with that of the structure which 

 Sabussow ('10) showed in his figure 10, and which he termed a 

 modified end-bulb of Krause. The absence in my preparations 

 of the nucleated capsule characteristic of the cylindrical end-bulb 

 of Krause can be explained by the fact that such structures do 

 not ordinarily stain in methylene blue. Although these organs 

 are somewhat smaller than the cylindrical end-bulbs in question, 

 their location and structure are such that the writer is inclined 

 to think that they are modified cylindrical end-bulbs of Krause. 

 As has been shown, the writer confirms one type of Sabussow's 

 end-bulbs, the first, which closely resembles Krause 's cylindrical 

 end-bulb (fig. 18, Sabussow's fig. 10). But the Russian author's 

 second type, namely, the large one containing a nucleated sheath,, 

 and having a zigzag course, has not yet been seen in the prep- 

 arations used for this study. However, there are present in 

 this material structures (portions of medullated nerve trunks) 

 which correspond so closely to the descriptions and pictures of 

 his second type of end-bulb (Sabussow's plate 1, figs. 5, 6, 7, 8, 9) 

 that it appears very probable that the two are identical. In 

 his figure 8, he shows 'end-bulbs,' which, to the writer, seem 

 clear examples of cut medullated fibers separating out from a 

 common trunk. Sabussow himself points out that medullated 

 fibers in this region branch repeatedly at the nodes of Ranvier. 

 His figure 7, a picture of two so-called end-bulbs, represents 

 apparently a portion of a medullated nerve fiber, which at one 

 of these nodes, divides into branches. In his descriptions he 

 states that the axis cylinder passes through the whole bulb ta 

 its very end. This is precisely what is found in a portion of a 

 medullated nerve (fig. 21) when cut obliquely. The 'ending* 



