OBSERVATIONS ON THE HISTOLOGY OF STRIPED MUSOLE. 77 



Connection of Nerve-ending with Muscle 

 Network. 



Nerve-endings may be divided into two main types, the 

 circumscribed and the diffused form. Between these types 

 there are many intermediate forms, as shown by Kilhne in his 

 classical work on ' Nerve-Endings/ ^ The uerve-endings in the 

 muscle of the snake form a good example of the circumscribed 

 variety. Here we have a localised end-plate, compact and non- 

 ramifying. This is also the common type in mammalian muscle. 

 In Dytiscus, on the other hand, we find the diffuse form, which 

 branches and ramifies nearly to the end of the fibre. 



In each case the nerve-ending, when stained by any of the 

 gold methods, is seen to consist of a slightly stained ramifying 

 portion, with darkly stained irregular masses between the 

 branches of the lighter stained portions. The lighter stained part 

 appears to be continuous with the axis-cylinder of the nerve. 



In attempting to demonstrate a connection between the 

 nerve-ending and the muscle-network there is great difficulty, 

 because the methods which best show the uerve-endings usually 

 disintegrate the muscle-fibre and destroy the network. The 

 best method of obtaining the nerve-endings is that employed 

 by Mays,^ and also, with modifications, by Kiihne,^ viz. the mix- 

 ture of arsenic acid, gold chloride, and osmic acid mentioned in 

 the first part of this j)aper. But this method usually destroys 

 the network, owing to the action of the arsenic acid. Another 

 difficulty arises from the fact that the connection, if it exists, 

 must take place underneath the nerve-ending, and hence in the 

 normal position of the parts it could hardly be seen. 



Dytiscus. — In one preparation of Dytiscus muscle prepared 

 by May's method I succeeded in finding a portion of fibre with 

 the network still intact (fig. II). A portion of the ramifying 

 nerve-ending is seen crossing the fibre transversely ; both the 



' " Untersucbungen iiber motorisclie Nerveneudigung," ' Zeit. f. Biol.,' 

 Bd. xxiii. 

 - ' Zeit. f. Biologic,' Bd. xx, 1884, 

 ' Loc. cit. 



