50 PHYSIOLOGY. 



nerves, as the muscular tissue. There is reason to believe 

 that every filament, however fine, is provided with the ulti- 

 mate branch of an artery, vein, and nerve. f*The direction 

 of the fibres of muscles varies ; in some, being parallel ; in 

 others, radiating in different directions. In some instances, 

 they form nearly or quite a circle, as the muscle which 

 closes the eye, and those of the intestinal canal ; in others, 

 they are penniform, or having their fibres disposed like those 

 forming the feathery part of a quill jj 



Two portions of muscle ; one of which, cr, is covered with mem- 

 brane ; the other, b, is uncovered ; c, the muscular fibres terminating in 

 tendon. 



27. [Muscular tissue is supposed to consist chiefly of 

 Jibrin, though some chemists state that it contains albumen, 

 gelatine, and osmazomefc These latter substances however, 

 are probably obtained from the cellular tissue which encloses 

 and dips down between the fibres of muscles. Fibrin con- 

 tains a larger proportion of azote, the element peculiar to the 

 animal body, than any other animal substance. The flesh 

 of young animals affords a large proportion of gelatine, while 



