1 6 Journal of Comparative Neurology and Psychology. 



sented in Fig. i, B and C. A separate non-medullated nerve («) is shown 

 which forms a small plexus on B, one fiber of which penetrates to a lower plane 

 than the others and ends by forming under the sarcolemma a knob like Fig. i, 

 B ; the other fibers pass on, one to end on B, the other on C. 



Fig. J. Zeiss D, Comp. occ. 4. Three medullated nerves (a), (6) and (c), 

 which pass to three separate muscle fibers, A, B and C, and which have ultra- 

 terminal fibrillae and interlacing of endings. Muscle fiber B is seen only in 

 part. 



Ftg. 4. Zeiss D, Comp. occ. 4. The type of ultraterminal fibrillae seen 

 most frequently. 



Fig. J', A. Zeiss D, Comp. occ. 4. An ending forming a complex net- 

 work on muscle fiber C. A nerve coiling round the primary terminal divisions 

 of another nerve (compare page 11 on relation of nerve to sarcolemma). The 

 nerve n goes to two muscle fibers, A and C. The nerve 3 on which no medull- 

 ary sheath was seen divides into two branches ; one of these ends undivided, 

 the other separates into two branches which run close together and parallel. 

 At (2) the upper branch coils round a primary fibril of the nerve ending on 

 muscle fiber A; in addition it gives off a fibril which disappears in adjoining 

 ■connective tissues. 



Fig. 5, B. Part of Fig. 5, marked (i), drawn with Zeiss oil immersion 

 1-12 Comp. occ. 4. 



PLATE II. 



Fig. 6. Zeiss 1-12 oil immersion, Comp. occ. 4. Sections cut 10 yu. 

 Nerve endings shown only in part, with ultraterminal fibrillae (I), (2) and (3), 

 one of these (i) with sheath. The main fiber is seen at n. From it a branch 

 to the right passes off and soon divides ; one of these divisions has been cut by 

 the sectioning, the other (i) passes to an adjoining muscle fiber, there to end 

 in a small termination like an end-plate with end knobs. The nerve sheath 

 could only be traced distinctly to the point where the nerve enters into contact 

 with the muscle fiber. 



Fig. J. Zeiss 1-12 oil immersion, Comp. occ. 4. Sections//. Stained in 

 orange G, acid fuchsin. Part of nerve ending lying over sarcolemma. This 

 dye colors the sheath of Henle rose-pink, the neurilemma pink, and the 

 muscle fiber orange. The medullary sheath was apparent at M just above the 

 node R, where the axis-cylinder divides into three branches which pass to the 

 muscle fiber. The sheath of Henle (H) is seen continued over R wituout at- 

 tachment, and two of its nuclei (Hn) were distinctly outlined. Within the 

 sheath of Henle and closely applied to the axis-cylinder, lay the neurilemma 

 N, attached to the node R. The primary terminal fibrils surrounded by the 

 sheaths lie over the sarcolemma which is distinctly marked beneath the sheath. 



Fig. 8. Zeiss apochomatic 1.5, Comp. occ. 6. Section 7.5 //. A primary 

 terminal fibril with sheaths. H, Henle's sheath; N, neurilemma; S, sarco- 

 lemma. 



Fig. g. Zeiss apochromatic 1.5, Comp. occ. 6. Section 5/i. A terminal 

 Tinob lying under the sarcolemma and covered by a cap which is chiefly com- 

 posed of the nerve sheath. Fine fibers pass at (a) and {b) from the sarcolemma 

 •to blend with the nerve sheath in the cap. 



