THE NUCLEUS CARDIACUS NERVI VAGI AND THE 

 THREE DISTINCT TYPES OF NERVE CELLS WHICH 

 INNERVATE THE THREE DIFFERENT TYPES OF 

 MUSCLE 



EDWARD F. MALONE 



The Anatomical Laboratory of the University of Cincinnati 



THREE FIGURES 



When one has carefully and critically studied in series of Nissl 

 preparations the brains of various mammals, there is revealed 

 the presence of constant cell groups whose cells invariably pos- 

 sess certain definite characteristics as to size, form and struc- 

 ture. A separation of two groups of cells based merely upon 

 differences in their histological characters is justified in the 

 present state of our knowledge, only when such differences are 

 constant and striking. When these conditions are fulfilled we 

 may conclude that such constant and striking differences in cell 

 character correspond to a difference in cell activity, just as in 

 other portions of the body. I have pointed out elsewhere that 

 very real differences in cell character have been neglected by 

 experimental workers, and that their results have been rendered 

 thereby of less value. Since the dorsal motor (sympathetic) 

 nucleus of the vagus is known to contain centers for the con- 

 trol of both heart muscle and smooth muscle, one would sup- 

 pose that any real difference in the cell character of various 

 portions of this nucleus would at once claim the attention of 

 the experimental worker and that he would attempt to inform 

 us as to the relation of these different types of cells to the 

 various functions of the vagus nerve. But such is not the case; 

 we are informed casually that some cells are large and others 

 small, and thereafter the cells are considered as if they were all 

 of the same type. 



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