MUSCULAR CONTRACTION IN TISSUE-CULTURES. 209 



organism this activity becomes controlled by various influences, such as the nervous 

 system, the differentiation of the cells, etc., yet when this tissue is removed from 

 these controlling elements, as in tissue-cultures, the muscle cell again undergoes 

 contraction as a part of its normal life processes. However that may be, the fact 

 remains that in tissue-cultures the muscle cell, whether originating from theamnion, 

 the heart, or the skeletal muscle, may exhibit this property. 



CONCLUSION. 



Contraction, characteristic of the amnion smooth muscle, the heart muscle, 

 and the skeletal muscle, takes place in the growth from these muscles in tissue 

 cultures in Locke- Lewis solution. 



The phenomenon of contraction, while characteristic for a given type of tissue, 

 is not dependent upon a complicated muscular structure such as myofibrils. 



The mechanism for the study of the phenomenon of contraction may be reduced 

 to a single, slightly differentiated, living cell in Locke- Lewis solution. 



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