192 Journal of Comparative Neurology. 



the nerve fibers terminate on the spindle shaped cells; while, on 

 the other hand, Frankenhauser, Lustig, Obregia and Brenheim 

 find that the nerve fibers terminate in the muscle cell, on or in 

 the nucleus, Arnold and Obregia go so far as to say that the 

 nerve fibers may pass through or over the nucleus and appear 

 again in the inter-muscular plexus (Arnold), or pass on and end 

 in the nucleus of some neighboring cell (Obregia). 



Our own results confirm the observations of those writers 

 who contend for a free ending of the terminal fibers on the 

 spindle shaped cells of involuntary muscle. Our sections were 

 obtained from the muscular coat of the stomach and intestine 

 of kittens, tortoises and fishes, stained in methylene blue and 

 alum carmine, the method here being the same as used for the 

 other motorial endings previously discussed. The sections were 

 from 5 to 7 /f in thickness. In such sections, studied under 

 the 1-12 oil imm., the cell outline of the spindle shaped muscle 

 cells, as also their nuclei,* may readily be made out; they are 

 stained red; the nerve fibers, blue. Figs. 22 and 23 may serve 

 to show the results obtained ; both sketches were made from 

 preparations obtained from the muscular wall of a kitten's 

 stomach. Preparations made from the intestine of the tortoise 

 and fish, show essentially the same kind of an ending, so that it 

 did not seem necessary to duplicate the figures. 



In Fig. 22, may be seen at a, a small varicose fibril from 

 the intramuscular plexus. The terminal fibers of this plexus 

 usually, as shown here, run parallel with the long axis of the 

 muscle cells, seemingly embedded in the inter-cellular cement 

 substance. Such terminal branches may, in sections 15 to 20 /^ 

 in thickness, be traced under a 1-12 in. oil imm., through 

 several fields of the microscope. From place to place, 

 short side filaments are given off from such terminal fibers, 

 which may be traced to a muscle cell, on which they terminate 

 in one or two nodular enlargements ; one such is shown in b, of 

 Fig. 22. A terminal fiber may, in this way, send side filaments 

 to 6 or 8 muscle cells, as it courses along in the intercellular 

 cement. Occasionally two or three short filaments end on one 

 cell, each in a small end-bulb, as may be seen in Fig 23 ; this 



