Huber-DeWitt, Nerve-Endings in Muscles. 221 



atrophy of the nerve trunk leads to atrophy of the muscle-fibers 

 within the spindle, though it is probable that it takes a consid- 

 erable length of time for changes to take place in the muscle- 

 fiber within the spindle." 



Spiller describes the muscle-spindle in a case of intense 

 muscular dystrophy. The muscle-spindles were normal, also 

 medullated "intramuscular nerves." He gives no observations 

 on the ending of the spindle-nerves. 



Horsley, in a brief note accompanied with photographs, 

 summarizes observations made on trans-sections of gastronene- 

 mii and solei of dogs and cats in which the sciatics were divided 

 at periods varying from 3 days to i year before the animal was 

 killed. 



Horsely shows that although the muscle-spindle seems to 

 undergo an apparent shrinkage from about the 17th day after 

 the section of the nerve, this shrinkage is parallel to the general 

 shrinkage which the atrophy of the muscle gradually undergoes 

 as a whole, the intrafusal fibers being apparently unaltered in 

 character. 



In a case of pseudo-hypertrophic paralysis, in which the 

 muscle-spindles were examined by Griinbaum, he finds "the 

 muscle-spindles were for the most part unaffected, but in a few 

 there was a diminution in size of an intrafusal fiber with a 

 deposit of hyaline material around." 



We wish finally to refer briefly, to that portion of Ruffini's 

 recent note on the sensory endings in striated muscle, in which 

 he summarizes his observations on the spindle-nerves. Ruffini 

 has studied more particularly the muscle-spindles in the cat, and 

 describes these three kinds of endings of the spindle nerves : — 

 primary, secondary, and plate-like. 



Primary endhigs. The large nerve-fiber going to the spin- 

 dle almost always divides into two or more secondary branches, 

 each of which divides into tertiary branches after having 

 passed through the capsule ; each of these ends on the intra- 

 fusal muscle fiber. These tertiary branches lose their sheath of 

 myelin, become broad, flat and ribbon Hke, and are either spir- 

 ally wound about an intrafusal fiber or run along one side of it 



