Huber-DeWitt, Neuro-tcndmous End-organs. i8i 



solution, with Fig. 4 of Plate XIII. which gives more nearly the 

 natural size of the organ. 



Reptilia. 



Our own observations on the termination of nerves in the 

 neuro-tendinous organs in reptilia agree more closely with those 

 made by Ciaccio than with those recorded by Golgi and Pan- 

 sini, who described a network of fine nerve branches, at the 

 nodal points of which thickenings are found. Ciaccio investi- 

 gated under reptilia the tendons of the interspinous muscles 

 of Coluber natrix and the tendon of the gastrocnemius of 

 Lacerta agilis. He found in these no true Golgi neuro-tendi- 

 nous end-organs, but nerve plaques situated in small tendinous 

 groups, primary as well as secondary. "The plaques," he says, 

 "consist of a confused intercrossing of very fine fibers, some 

 filamentous and some ribbon-like, arranged in two planes and 

 beset with projections of different form and size." In cross sec- 

 tions, he showed that the fibers, near their termination, pene- 

 trate the primary tendon bundle and surround one or several of 

 the secondary tendon bundles composing it. In our investiga- 

 tions, we have used almost exclusively the tendons of the pos- 

 terior extremity of Emys meleagaris, especially the flat tendi- 

 nous aponeuroses of the quadriceps extensor and the tendon of 

 the gastrocnemius. In this animal as in the frog, we have fre- 

 quently been able to trace large medullated nerves with rather 

 short internodal segments, for considerable distances, which, at 

 each node of Ranvier, give off a medullated branch and some- 

 times more than one. This, after a longer or shorter course, 

 terminates in a more or less complex end-arborization. In some 

 cases the medullated nerve divides into four or five finer medul- 

 lated nerves, some of which break up at once into a number of 

 non-medullated fibers ; others extend for considerable distances 

 along the tendon and toward its extremities, giving off at 

 intervals side branches, which either are or soon become non- 

 medullated or divide into numerous non-medullated nerves. 

 Thus, along such an ending, very large numbers of such tufts 

 may be seen. After losing the medullary sheath, the fibers 



