64 PRACTICAL MICROSCOPY. 



transparent sheath the sarcolemma. They are aggregated, forming 

 primitire fasciculi, which are again united to form the larger bundles 

 of a complete muscle. The connective tissue uniting the primitive 

 fibres is termed endomysium ; while that uniting the primitive bun- 

 dles is the perimysium. 



The primitive muscular fibres exhibit marked cross striations with 



FIG. 49. STRIATED MUSCULAR FIBRES PROM THE TONGUE, TEASED AND STAINED WITH 



A. A fibre, with the muscle substance wanting, from stretching during the teasing, the sar- 

 colemma alone remaining. 



B. Partly separated disc of Bowman. 



C. Ultimate fibrillae. 



D. A blood capillary. X 400. 



faint longitudinal markings, the former being produced by alternate 

 dark and light spaces. 



Fig. 48 illustrates diagrammatically the theory of the structure of 

 a primitive fibre: A indicates the sarcolemma. The dark substance 

 B, B (Krause's membrane) divides the fibre completely, and is united 

 with the sarcolemma. The light spaces C, C, between Krause's 

 membranes, containing the contractile substance, are termed the 

 muscular compartments or discs of Bowman. This contractile sub- 



