EXPLANATION OF PLATE IL 

 Fig. 5. Cross-section of two small trabeculae. Stained in iron hsematoxylin 

 and followed by Van Gieson's. Leitz 01). 12, Oc. 3. Camera Incida. X 1,000. 

 Lettering the same as Fig. 7. 



Fig. 6. Cross-section of a trabecnla. Stained in iron htematoxylin and fol- 

 lowed by Van Gieson's. Leitz Ob. 12, Oc. 3. Camera lucida. X 1,000. 

 Lettering the same as Fig. 7. Shows two nuclei at same level, each in its 

 axis of protoplasm. 



Fig. 7. Cross-section of a large trabecula. Stained in iron hsematoxylin 

 followed by eosin. Leitz Ob. 12, Oc. 3. Camera lucida. x 1,100. a— Nuclei 

 of connective-tissue sheath, b — Connective-tissue sheath around trabecula. 

 c — Protoplasm within sheath, d — Nucleus of muscle fiber, e — Axial proto- 

 plasmic region in which nuclei are embedded. 



Fig. 8. Longi section of a trabecula. Iron hiematoxylin followed by Van 

 Gieson's. Leitz Ob. 12, Oc. 3. Camera lucida. X 1,100. f — Connective- 

 tissue membrane, g — Strand of contractile fibrils. Other letters the same 

 as in Fig. 7. 



Fig. 9. Longi section stained with Mallory's connective-tissue stain. Color 

 shown as in preceding figures. Leitz Ob. 12, Oc. 3. X 1,100. a — Cleft divid- 

 ing the trabecula into which the connective tissue sheath has entered. The 

 appearance is similar to what Heidenhain figures as the "daughter sarco- 

 lemma." 



Fig. 10. Longi section. Iron hsematoxylin followed by eosin. X 1,100. a — 

 connective-tissue sheath which persists between the fusing trabeculae until 

 the cross striation becomes synchronous. 



