158 



MYOLOGY. 



fusiform or elongated cells, which become apparent after macer- 

 ation of the tissue in dilute hydrochloric acid or other reagents, 

 or it may be without any such preparation. These cells are 

 the contractile cells of Kolliker, and in them au elongated nucleus 

 may be visible. The fasciculi vary very greatly in size in dif- 

 ferent situations, and often crossing each other, they give the- 

 tissue in some parts a mesh-like appearance. The non-striped, 

 tissue is very abundant, being found in the walls of the ali- 

 mentary canal and hollow viscera, in gland ducts, in the 

 coats of blood-vessels, in the skin, and 

 elsewhere. 



Both varieties of muscular tissue are 

 plentifully supplied with blood, and in stri- 

 ated tissue the capillaries or minute blood- 

 vessels are arranged longitudinally with 

 transverse connecting branches, but they 

 do not penetrate the sarcolemma, they and 

 the larger vessels alike being found in the 

 perimysium or interstitial connective tissue. 

 The striated tissue is supplied with nerves 

 from the cerebro-spinal system, but the non- 

 striated tissue receives its supply from the 

 sympathetic system, and the vital stimulus 

 conveyed by either of these causes the contraction of the fibres. 



The description of the arrangement of involuntary tissue forms 

 no part of the present section of our subject ; the tissue is 

 described here chiefly in order that its structure may be com- 

 pared with that of the voluntary kind. 



TENDONS. 



The tendons in which voluntary muscles terminate at either 

 end are structures resembling ligaments in their composition, 

 being formed of white fibrous tissue mixed with yellow fibres. 

 Like ligaments, they are practically non-elastic, and while they 

 attach the muscles to the bones, they merely transmit the action 

 of the former to the latter, and are therefore passive instruments 

 of motion. 



The extremity of a muscle which has the most fixed attachment 

 is called its origin ; the other extremity attached to the more 

 movable structure, its insertion. The tendon of insertion is 

 often longer than that of origin, which is frequently rudimentary. 

 In some cases both extremities are equally movable. 



YiQ. 69. 

 A, Non-striated muscular 

 fibres; a a. The component 

 fusiform cells; 6, 6, The 

 nuclei. B and C, Single cells 

 mora highly magnified; C 

 having been treated with 

 acetic acid. 



