FUNCTIONS OP THE SWEAT-GLANDS. 279 



mechanical pressure present in induced sweating, that to 

 which reference was made when excessive muscular activity 

 was studied: i.e., increased cardiac activity. \Yhen pilocar- 

 pine is given in sufficient doses to produce marked diaphoresis, 

 the heart-beat is increased in power, but lowered as to rhythm. 

 During the sweating from violent physical exercise the heart- 

 beats are increased in power, but quickened in rhythm. Hence 

 there is a more or less marked loss of balance between the 

 various functional features that contribute to the general 

 process when induced sweating occurs, while there is perfect 

 balance in all these when diaphoresis occurs physiologically as 

 it does during unusual physical exercise. It is only when the 

 centers are able to adequately utilize the two subdivisions of 

 the single efferent nerve that supplies glands concurrently with 

 perfect functional activity of the suprarenal system, that nor- 

 mal i.e., physiological diaphoresis may be said to occur. 



In Onuf and Collinses cat No. 2 physiological sweating 

 supervened; but the centers could no longer transmit efferent 

 impulses to the secretion-exciting fibers nor to the arterioles 

 from which the tubular capillaries sprung. The functional 

 process therefore failed. Had it received the aid of the pow- 

 erful blood-pressure that pilocarpine procured through the 

 suprarenal overactivity, however, it would not have fallen 

 short. Nor did it when, in this same animal, the alkaloid was 

 put to the test. 



In analyzing the manner in which the nervous supply of 

 the sweat-glands originates and its relationship with the tubuli 

 we will test the following postulate, suggested by our study of 

 the innervation of the muscles and submaxillary glands: 



1. All efferent nerves to the periphery and to voluntary mus- 

 cles are subdivisions of the one great motor system. 



2. There are but two divisions of the great motor system: (1) 

 the "vasoconstrictor" nerves, and (2) the "excito-regulator" nerves, 

 which incite and govern the metabolism of the glandular elements. 



In moribund cats, while the heart-action is growing 

 weaker, sweating of the toe-pads occurs; and if these are not 

 pigmented they become pale and exsanguine (M. Duval). This 

 corresponds with the profuse sweating of death-agony in human 

 beings, attended, of course, with great pallor or lividity. We 



