CHAPTER VIII 



MUSCLE TISSUE. 



This variety of tissue is of mesoblastic origin, and is 

 divided into three classes : voluntary, involuntary and 

 heart muscle. All muscle tissue is rich in blood vessels, 

 lymphatics and nerves. The blood vessels break up 

 into capillaries, which form a net work around each 

 individual fiber. The nerves terminate in special end- 

 organs under the sarcolemma. 



The voluntary or skeletal muscle is the most wide- 

 ly distributed. It forms all the skeletal muscles, and 

 is under the control of the will. It is composed of 

 long, cylindrical fibers, by some authors called cells. 

 These are the largest cells in the body so large that 

 one cannot be placed in the field of the microscope at 

 once. Sometimes they are i l /2 inches long. They 

 are all surrounded by a delicate membrane, or cell-wall, 

 called sarcolemma, just under which are placed the 

 nuclei of the cell. The transverse striations that are 

 seen all along the course, are said to be due to the pres- 

 ence rnd make-up of the sarcous elements. There are 

 seen running along the long diameter of the cell deli- 

 (56) 



