1 88 Journal of Comparative Neurology. 



ing, consisting of one meduUated nerve which branches little 

 and shows only a few terminal plaques. 



Longitudinal sections, stained in methylen-blue and coun- 

 ter-stained in alum carmine, as represented in Plate XV, Figs. 

 1 6 and 17, show that the few large tendon fasciculi, which enter 

 the spindle, break up into smaller fasciculi and these still far- 

 er divide and then re-unite at the distal extremity of the spin- 

 dle ; that the intrafusal tendons have very numerous nuclei, 

 oval or elHptical ; that the non-medullated fibers have a sinuous 

 course, now on and now between the tendon bundles, while 

 the terminal plates are granular and seem to pass between the 

 bundles of fibrillar connective tissue. In some cross sections, 

 as shown in Plate XV, Figs. 18 and 19, we see a thin connect- 

 ive tissue capsule, which is seen to be wanting in others. We 

 see also that the meduUated nerves pass in the connective tissue 

 surrounding the fasciculi while the non-medullated fibers, as 

 Ciaccio has mentioned, penetrate the fasciculus and end on the 

 small groups of fibrillar coimective tissue of which the fascicu- 

 lus is composed. 



Mammalia. 



Concerning the general structure of the neuro-tendinous 

 end-organs in the different forms of mammalia studied, our ob- 

 servations have not differed materially from those of Golgi, 

 Cattaneo and Ciaccio. Concerning the form of the end-organs, 

 we may say that the true spindle-shape is not quite uniform, 

 the amount of enlargement in the equatorial region varying so 

 much that at times we find the spindles reduced to long, slen- 

 der cylinders, having nearly the same dimensions throughout 

 their length, but usually tapering slightly at the ends. This 

 cyhndrical form seems especially common in the dog. The 

 length of the organ, according to Cattaneo, varies from 80^ to 

 800 //, the width, from 50 ^^ to 400 ;/. These figures seem to us 

 not correctly given in the text cited and do not correspond with 

 the proportions of those end-organs figured by Cattaneo. K61- 

 liker gives his measurements of the human spindle as 1.28 mm. 

 to 1.42 mm. long and o. 17 mm. to 0.25 mm. wide at the mus- 



