211 



LECTURE X. 



Of Muscular Tissue Protoplasm of Muscle Contrac- 

 tile and Vital Movements Contraction of Muscle 

 Voluntary and Involuntary Muscle Unstriped or 

 Involuntary Muscle ; from the Bladder ; from Arte- 

 ries Structure Striated or Striped Muscle The bio- 

 plasm of Muscle Formed material of Muscle Sar- 

 colemma Development of Muscular Tissue Changes 

 occurring in old Muscular Tissue Fatty Degenera- 

 tion. 



256. Peculiar property of muscle. No phenome- 

 non has been discovered in connection with, the action 

 of any of the tissues already considered, which at all 

 resembles that which is the peculiar characteristic of 

 muscle. In both muscle and nerve "molecular" 

 changes, remarkable for their rapidity and repetition, 

 take place, the exact nature of which is still doubtful. 

 Although these tissues are associated and intimately 

 related to one another, it is doubtful if the changes 

 in muscle and nerve are of the same kind. If in 

 nervous action there is an actual movement of the 

 particles of matter entering into the formation of the 

 nerve fibre, the movements are more subtle, and of a 

 different character ; nor are they evident like those 

 which occur in all contractile tissues. The striking 

 alterations which take place when the muscle, or part 

 of it, passes from the state of rest into that of active 

 contraction, can be seen and measured while under 

 the microscope. An actual shortening can be ob- 

 served to take place in each elementary portion of 

 muscular tissue every time it contracts. What the 

 muscle loses in length it gains in width, or nearly so, 



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