ENDING OF NERVES IN VOLUNTARY MUSCLE. 



155 



terminal organ, and receives consequently but one nerve-fibre. As, 

 moreover, the fibres of a nerve undergo division, probably repeated 

 division, before ending, it fol- 

 lows that one fibre in a nerve- Fig. lOC. 

 root or trunk may supply 

 several muscular fibres. 

 Longer muscular fibres have 

 two or more end-phates. 



The motorial end-]5lates have 

 now been recognised in mamma- 

 lia, birds, and scaly rejitiles. They 

 were discovered by Eoug-et* in 

 lizards and wann-blooded animals ; 

 they had l)een previously found, 

 but in a modified form, hy Doyere 

 and others in various invertebrata. 



In amphibia (fig. lOli) there is 

 no trae end-plate, but the branches 

 resulting from the division of the 

 medullated nerve lose their medul- 

 lary sheath on i^enetrating the 

 sarcolemma. and are continued as 

 pale fibres. These give off branches 

 which run for a shoit distance 

 parallel with the axis of the fibre 

 between the sarcolemma and the 

 muscular substance, terminating 

 abruptly by rounded extremities. 

 These pale fibres present here and 

 there slight enlargements, con- 

 nected with which are granular, 

 pear-shaped nuclei (A), not to be 

 confomided -svith the jn'oper nuclei 

 of the muscle (r). A fine tortuous 

 fibril is stated by Klilme to be 

 given off from the i^ale fibre to 

 each of these graniilar nuclei, and 

 to tenninate in it by a bulbous 

 enlargement. 



The above account may be taken 

 as the one most in accordance 

 with the more recent researches 

 on the subject, and as probably, 

 on the whole _ correct. It is, 

 however, only r ight to state that 

 the existence of the end-plates has 

 been lately called in question by 

 G-erlach, who from the study of 

 muscular fibres ijrejjared ■with 

 chloride of gold has amved at 

 the conclusion that the axis-cylin- 

 der of the nerve after passing 

 through the sarcolemma forms 



Fig. 106. — Nerve-Ending in Muscle of Frog 

 (Kiibne). 



a, one of the branches of the medullated fibres 

 passing within the sarcolemma ; b, b, gi-anular 

 pear-shaped nuclei ; c, c, nuclei of i^rimitive 

 sheath ; e, muscle nuclei. 



a close network of minute varicose fibrils 



* Comptes Rendus, Iv., 1862. See also Krause, Gottinger Nachrichten nnd Zeitsch. 

 f. rat. Med. (various papers): Engelmann, Unters. ueber d. Zusammenh., &c. , 1863: 

 Kiilme, Virch. Arch, (various papers), and article in Strieker's Handbook of Histology, 

 where also a complete account of the history and literature of the subject will be found. 



