394 THE TISSUES. 



2. The myoline is the demi-solid substance filling the myolemma, 

 and on the surface of this are the transverse markings before men- 

 tioned. It consists, first, of very minute threads, called fibrillce, 

 placed side by side, from 2T5 J^ to ^-Q-Q of an inch in diameter, and 

 averaging about Tirim? f an i nc ^ ''between which is, secondly, the 

 muscular juice, to be described under the chemical composition of 

 this tissue. Each one of these fibrillae has its own transverse mark- 

 ings. Fig. 250, 1, shows a fibre splitting into its compound fibrillae 

 in consequence of maceration. The same cause sometimes produces 

 a transverse cleavage of the fibres ; in which case the fibre has been 

 described as being made up of superimposed disks, instead of fibrillae. 

 Fig. 250, 2, represents this form of cleavage. Often, atlso, a longi- 

 tudinal striation is apparent. The fibrillae are not tubular in man 

 (as in some of the lower animals), but are homogeneous throughout. 

 The fibrillae are connected together by an albuminous tenacious 

 intermediate substance of a double nature: viz., the "muscular juice'* 

 hereafter to be described; and a granular molecular substance 

 probably fat in part which certain distinguished microscopists 

 have seen lying between the extremities of the fibrillae of a fibre 

 which had been transversely divided. Each fibrilla is also by Todd 

 and Bowman regarded as being composed of cells, called "the sar- 

 cous elements," as represented in Fig. 250, 5 and 6. 

 Fig. 252. These cells average about -g-JvQ f an ^ nc ^ * n ^i- 



ameter ; and as the alternate ones are often larger 

 than those between them, the striated appearance 

 of the fibrillae has sometimes been accounted for 

 in this way. 



Peculiarity. In the heart (of man, and proba- 

 bly of all mammals), anastomosing and dividing 

 fibres are found. Branched fibres are also found 

 in the human tongue, (Fig. 252.) 



The striated muscular tissue is abundantly sup- 

 plied with bloodvessels and nerves (both the fine 



Anastomosing fibres , , /i \ i . -i -.1 



from the human, heart, and the coarse nerve-fibres), and scantily with 

 (KoUiker.) lymphatics. (See Section II. of this chapter.) 



Chemical Composition and Physical Properties of Striated Muscular 



Tissue. 



There is reason to believe that the chemical composition of the 

 two forms of muscular tissue is identical. C. Schmidt supposed he 



