ELECTROMOTIVE ACTION IN NERVE 



341 



In the eye-muscles of the frog, the predominating nerve-endings 

 recall the simpler types of low amphibians (Proteus) and fishes 

 (Eetzius, I.e.). The contrast between eye-muscles and skeletal 

 muscles in mammals is in this respect even more striking (cf. 



m 



FIG. 224. End-plates (fresh) of Lcwerta agilisin 0*6 % NaCl. Expansion with nuclei. 



Eetzius, I.e. p. 48). While the former invariably exhibit charac- 

 teristic end-plates, the latter present terminal arborisations which 

 vary in a marked degree from the ordinary type, and again re- 



Fio. 225. End-plates from muscle-fibre of mouse. Expansion of the nerve in profile. 



semble the forms that obtain in the lower animals. The rami 

 that extend longitudinally in the muscle are but little branched, 

 and bear a varying number of " terminal discs." Of interest, too, 

 are the " simplest forms of end-branches " observed by Eetzius 

 (I.e. p. 48) in the same object (and confirmed by Biedermann), 

 which consist of an unbranched non-medullated lateral fork of a 



