1 86 Journal of Comparative Neurology, 



two or three primary medullated branches, each of which sooner 

 or later re-divides and ends in one or several non-medullated 

 fibers. Side branches are also given off, which, after a very- 

 short course, divide into two or three non-medullated fibers, 

 which usually run nearly parallel to the main nerve of the end- 

 ing. In the bird, as in the turtle, the characteristic appearance 

 of the end-tuft is produced by peculiar, fantastic enlargements, 

 granular in appearance and of the most varied size and shape, 

 which beset all the non-medullated fibers. Sometimes they are 

 quite regularly round or oval, but oftener they are very irregu- 

 lar, plate-like, with prominent projections, which may be 

 pointed, blunt or round, or they may resemble long leaves 

 somewhat twisted. These enlargements are in general longer 

 and more complex than those that we find in the turtle, the form 

 which seems to predominate being that in which the non-med- 

 ullated fiber itself enlarges, widens out into a large, irregular 

 granular plate, other granular plates, round, oval, rectangular, 

 club-shaped or spike-like, being added on, now at the side and 

 now at the end, and still others, until we have a long, irregular 

 string of such granular masses, at no point showing a return to 

 the normal size of the non-medullated fiber. 



The complexity of the ending may be varied by the num- 

 ber of times that the non-medullated fiber branches before thus 

 spreading out into this terminal enlargement, and by the num- 

 ber, size and shape of the granular plates that are thus pieced 

 on to the simple terminal enlargement. In addition to these 

 widenings of the main stem, we have also numerous varicosities, 

 which may rest directly on the main stem before its final en- 

 largement, or may be separated from it by a slender pedicle. 



The medullated nerves are usully quite straight throughout 

 their length, but the non-medullated fibers wind in long, sinu- 

 ous waves, now for some distance on the one surface of the 

 tendon fasciculus, now partly surrounding it and now coiling 

 from one fasciculus to another, finally entering one of the peri- 

 pheral fasciculi and passing between the secondary bundles of 

 tendon fibers composing it, while the side and terminal enlarge- 

 ments enclasp the bundles of tendon fibers, partly encircling 



