NERVES OF A MUSCLE. 



459 



contact with it. This branched arrangement of the axis-cylinder under the sarcolemma, Kiihne 

 has called a "motor-spray" ( ' ' motorisches Geweih "), and the mode of distribution of the 

 branches varies in different classes of animals. In the frog (fig. 310), tailed amphibians, and 

 birds, the hypolemmal branches of the axis-cylinder form bayonet-like and branched endings. 

 In the lizard, snakes, and mammals, the branches are often curved or twisted, and possessed of 

 lobes, and as the division is very variable, there is every form from a simple hook-like bend to a 

 highly arborescent termination. ] 



[Where a motor nerve enters a muscular fibre at the eminence of Doyere, the sheath of the 

 nerve-fibre, known as the perineural or Henle's sheath ( 321), becomes 



continuous with 



a A a 



Fig. 310. 



the sarcolemma. The eminence itself consists of 

 mass of protoplasm or sarcoplasm called 

 by Kiihne sarcoglia which contains gran- 

 ules and nuclei, the latter with a mem- 

 brane and peculiar nucleoli ; the nuclei 

 themselves are the fundamental or basal 

 nuclei of the sarcoglia. The outer surface 

 of the eminence is covered by a mem- 

 brane called telolemma by Kiihne, but 

 which in reality consists of two mem- 

 branes, an outer 

 one, the epilemma, 

 continuous with 

 the perineural or 

 Henle's sheath, and 

 an inner one, the 

 endolemma, the 

 continuation of the 

 sheath of Schwann 

 of the nerve-fibre, 

 both ultimately be- 

 ing connected with 

 the sarcolemma. As 

 the nerve pierces 

 r> c1 . c the muscular fibre, 

 Profile, view of it loses its myeline! 



B, bed ; D, large granule in B ; C, nuclei of the bed ; E, muscle nuclei 

 F, contractile substance. 



the telolemma (fig. 311). 



Fig. 310. Motor nerve-ending in the frog (Kiihne), 



entrance of the nerve ; b, b, nuclei of the branches of the axial cylinder , 

 c, c, c, nuclei of Henle's sheath ; e, muscle nuclei. Fig. 311. Motor -_ t ^ e k era tm 

 nerve-ending in lizards, mammals, and man. Schematic after Kiihne. A, |i,' li. __ v ;i QTY1TY1Q 

 axis-cylinder ; A A , terminal branches of A ; a, a, myelin of nerves ; b, f+heaxis-cvlinder 

 perineural or Henle's sheath, and its nuclei (c) ; d, nuclei of telolemma ; ,, . ,, sm . av l 



like ending is ac- 

 companied only by 

 The telolemma contains nuclei which are derived from Henle's 

 sheath (Kiihne). 



[In some animals, such as the lizard, in order to see the nerve terminations, it is sufficient to 

 stain portions of fresh muscles with Delafield's logwood. ] 



[Nerve-endings, then, are sublemmar, and the terminations of the nerves never 

 penetrate into the depth of the muscular fibre, but come into direct contact with 

 the contractile prism or cylinder moistened by the fluids of the muscle. In 

 many cases the striped substance is separated from the blunt nerve-endings by some 

 of the sarcoglia, which in some cases penetrate and traverse the other constituent 

 of the fibre. The latter Kiihne has called " rhabdia." The antler-like division of 

 the axis-cylinder or spray, in contact with the muscular substance, serves to conduct 

 the excitation from the former to the latter, but excitation of the muscular sub- 

 stance is never transmitted in the reverse order to the nerve-ending (Kiihne).] 



Each muscular fibre of the cray fish is supplied by two nerve-fibrils arising from separate 

 axis-cylinders (Biedermann). 



Sensory fibres also occur in muscles, and they are the channels for muscular 

 sensibility. They seem to be distributed on the outer surface of the sarcolemma, 

 where they form a branched plexus and wind round the muscular fibres (Arndt, 

 Sachs) ; but, according to Tschirjew, the sensory nerves traverse the substance of 

 the muscle, and after dividing dichotomously, end only in the aponeurosis, either 



