1 82 Journal of Comparative Neurology. 



which we believe are under the sarcolemma. The terminal 

 branches which are non-meduUated, are entirely devoid of any 

 sheath; even under the 1-12 in. oil imm., no trace of the sheath 

 of Schwann, which, according to KoUiker, accompanies such 

 branches to their termination, can here be made out. The 

 same may be said of muscle stained in methylene-blue and cut 

 parallel to the long axis of the muscle fibers, the sections being 

 further stained in alum carmine, The terminal branches (hypo- 

 lemmal fibers) are, as Fig. 12 may show, devoid of any cover- 

 insf of their own. The neurolemma becomes continuous with 

 the sarcolemma as soon as the nerve fiber passes under the latter. 

 See Fig. 14, n. I. Sihler would, if these observations are cor- 

 rect, be in error when he states that neither the sheath of 

 Schwann nor Henle's sheath is continuous with the sarcolemma. 



The myelin of the medullated fiber stops abruptly as soon 

 as the axis cylinder passes under the sarcolemma ; this point 

 needs no further discussibn. 



Concerning the structure of the hypolemmal branches of 

 the axis cylinder in frog's muscle, the statements above made 

 on the hypolemmal nerve branches in rabbit's muscle are 

 equally applicable. Kiihne and Feist describe an axial 

 thread and stroma ; Cuccati, peripheral granules ; and Retzius 

 finds sometimes an axial thread, and again the granules men- 

 tioned by Cuccati, in picrate of amitionium fixed methylene 

 blue stained muscle tissue, but not in such tissue examined be- 

 fore such fixation. In our sections of frog's muscle, stained in 

 methylene blue and alum carmine, the appearance most gener- 

 ally seen is shown in Fig. 12. The hypolemmal branches 

 present a fine granular appearance, are often more or less vari- 

 cose and often show marked differences in thickness in the 

 course of a branch. Now and then what might have been 

 interpreted as an axial thread was seen, this, however, very 

 seldom and only in some of the hypolemmal branches. 



In sections giving a surface view of the muscle fibers of 

 the frog, double stained in methylene blue and alum carmine, 

 it may be seen that the muscle nuclei are more numerous in 

 that portion of the muscle fiber receiving the ramified ending 



