350 



NEllVES OF VOLUNTARY MUSCLES. 



parts in gold preparations is well exhibited in figs. 411, 412. Applied to the branches 

 of the ramification small granular nuclei (fig. 414, n) are seen at intervals ; these 

 nuclei of the arborisation are different from the clear nuclei of the bed (V), and also 

 from the flattened nuclei of the sheath which lie immediately under the sarcolemma 

 covering the end-plate, and which resemble the nuclei of the sheath of Schwann of 

 the nerve. The sarcolemma over the situation of the nerve-ending is slightly raised 

 above the general surface (fig. 410, a). It would appear that in mammals each 



dr- k- ' I 



, S|rjl f|M- 



Fig. 411. MOTOR END-ORGAN OF A LIZARD : GOLD PREPARATION. (Kiihne.) 



n, nerve-fibre ; r, terminal ramification of axis-cylinder ; m, clear substance surrounding the 

 ramification (matrix) ; b, granular bed or sole of the end-organ. 



Fig. 412. CROSS-SECTION OF MUSCULAR FIBRE AND END-ORGAN OF LIZARD : GOLD PREPARATION. 



(Kiihne.) 

 r, terminal ramification of axis-cylinder ; m, matrix ; b, nucleus of bed ; t, nucleus of telolemma. 



Fig. 413. MOTOR END-ORGAN OF HUMAN MUSCLE : GOLD PREPARATION. (Kiihne.) 

 n, medullated nerve-fibre ; r, terminal ramification of axis-cylinder. 



muscular fibre has but one terminal structure, and receives consequently but one 

 nerve-fibre. As, moreover, the fibres of a nerve undergo division, probably repeated 

 division, before ending, it follows that one fibre in a nerve-root or -trunk may supply 

 several muscular fibres. In reptiles the longer muscular fibres may have two or more 

 nerve-endings. 



The shape and extent of the terminal ramification of the axis-cylinder within 

 the end-organ varies greatly, not only in different classes of animals, but also in 

 animals belonging to the same class, and there is even some variation in individuals 

 of the same species, as is evident from the various representations of the end-organs 

 of the green lizard, which are here given. On the whole, it may be stated that the 

 terminal ramification is most compact in mammals and reptiles and least so in 



