Huber-DeWitt, N euro-tendinous End-organs. 183 



divides dichotomously, one of the resultant branches termin- 

 ating quickly, while the other gives rise to two sets of tufts, be- 

 fore breaking up into its final arborization. 



Longitudinal sections, as represented in Plate XIV, Figs. 

 7 and 8, show that in the turtle, as in the frog, the tendons on 

 which these nerve endings are arranged, have not the character- 

 istics of ordinary tendon, but have smaller tendon fasciculi and 

 many more nuclei, both fasciculi and nuclei staining more 

 deeply than the surrounding tendon. The endings are usually 

 found deeply embedded in the tendon and may even be nearer 

 its superficial surface than its muscular face. In some cases, 

 however, as in Plate XIV, Fig. 7, they are found just at the 

 boundary of muscle and tendon. We see also that the terminal 

 fibers have a somewhat undulating, serpentine course, winding 

 about or between the tendon fasciculi, while the terminal plates 

 may enclasp or partially surround the smaller bundles of tendon 

 fibers. Neither the spirals nor the rings, however, which are 

 so strongly emphasized by Ciaccio in both his figures and his 

 descriptions as a most characteristic feature of the terminal 

 plaque, seem, in our preparations and figures, so definite and 

 strongly marked a feature of the ending as his figures would 

 seem to indicate. This fact, which we note in all our prepara- 

 tions from all species of vertebrates studied, may, it seems to 

 us, be due to the fact that, while the gold chloride stains, not 

 only nerve fibers, but also tendon fasciculi, connective tissue, 

 tendon cells and nuclei, or may precipitate in the lymph spaces 

 or semi-fluid ground substance, so that the appearance is often 

 deceptive, the methylen-b]ue far more sharply differentiates the 

 nerve structures from all other tissue elements of the end-organ. 

 In many preparations which we believe to have been perfectly 

 stained and in which only the nerve fibers and their terminal 

 ramifications were blue, we have found no rings, such as Ciaccio 

 finds in all his preparations, except those from the amphibia, 

 and no spirals, the rings being reduced to a clamp-like partial 

 encircling of the tendon by the terminal disks, and the spiral to 

 an occasional loose winding of the fine terminal fibers in and 

 out between the bundles of tendon. 



