Huber-DeWitt, Neroe-Endings in Muscles. 229 



Figs. I to ^. Surface view of muscle fiber and nerve ending. 



Figs. 6 to S. Longitudinal section of muscle fiber and motor ending. 



Figs, p to II. Cross-section of muscle fiber and nerve ending. 



Figs. 12 to i^. Nerve ending in amphibian muscle — frog. 



Fig. 12. Surface view of muscle fiber and nerve ending. 



Figs. 13 to 14. Cross section of muscle fiber of frog and hypolemmal nerve 

 fibers. 



The lettering is here the same as in the previous figures. 



Figs, i^ to 2T . Ending of nerve fibers on cardiac muscle of the auricle of 

 the cat's heart. 



Figs, ij to 20. Surface view of cardiac muscle cells with nerve endings of 

 varying degrees of complexity. 



Fig. 21. Cross section cardiac muscle cell with nerve ending. 



Figs. 22 to 24. Ending of nerves in involuntary, smooth muscle from mus- 

 cular wall of the intestine of a cat. 



Figs. 22 to 2^. Longitudinal section. 



a. — axis cylinder terminating. 



/5.— termination . 



n — nucleus of the cell. 



Fig. 24. Cross section of involuntary muscle cell through the point where 

 nerve fibril terminates. 



PLATE XV. Nerve-ending in Muscle-spindles. 



c— capsule. 



a. s. — axial sheath. 



c. n. — connective tissue sheath, surrounding each intrafusal fiber; only here 

 and there designated. 



i. f, — intrafusal fiber. 



p. a. s. — periaxial space. 



s. n. — medullated spindle-nerve. 



H. S. — Henle's sheath. 



s. ni. — striated muscle fiber from muscle, given to show the relative size of 

 intrafusal and the other striated muscle fibers. 



Sy. n. — sympathetic nerve fiber — vaso-motor fiber. 



bl. V. — blood vessel. 



Nerve fibers and endings blue, all other stuctures red. 



Figs. 2S to 2j. Muscle-spindles of amphibia. 



Fig. 2^. Longitudinal section of the distal portion of the muscle-spindle. 



Fig. 26. Cross section of a muscle-spindle at the place of entrance of a 

 spindle-nerve. 



Fig. 2-/. Cross section of the distal portion of a muscle-spindle. 



Figs. 2S to JO. Muscle-spindles of tortoise. 



Fig. 28. Longitudinal section through equatorial region, showing entrance 

 of spindle-nerve. 



Fig. 2g. Cross section of distal portion of muscle-spindle. 



Fig. JO. Cross section of muscle-spindle through place of entrance of 

 spindle-nerves. 



