298 MATHEWS. 



Most of these facts, brought out chiefly in the sahvaiy glands, 

 have been found to be true for other glands. The independ- 

 ence of blood pressure and secretion, the inhibitory action of 

 atropine, and an increase in concentration of the secretion coinci- 

 dent with a more rapid flow, have been observed by Afanassiew 

 and Pawlow," Gottlieb,^-' Pawlow and S/'^ Simonoskajain the pan- 

 creas, stomach and other glands, in which secretion is normally 

 accompanied by vaso-dilation. Sweat may be secreted during 

 vaso-constriction or vaso-dilation, and in the cat's foot, twenty 

 minutes after ligaturing the artery or cutting the leg from the 

 body/" The skin glands of amphibia can secrete in the total 

 absence of blood supply/^ Moreover, of recent years, the im- 

 portance of the condition of the secreting cells, as a factor of 

 secretion, has been clearly realized. The quick paralysis of 

 some secretions during dyspnoea or by the action of drugs has 

 emphasized this factor of secretion. Even in the kidney, where 

 secretion apparently more nearly approaches a filtration, it has 

 been shown that the condition of the capillary, or glomerular 

 epithelium, and the character of the blood, exerts an influence 

 on the secretion.^ The possibility at once suggests itself that 

 if the condition of the cells is so readily affected by external 

 agents it may be modified by direct nerve action. The very 

 rich nerv^e supply of many glands and the intimate association 

 of nerve end and gland-cell undoubtedly bring strong confirma- 

 tion to this supposition. 



From this brief outline the extreme complexity of the problem 

 of secretion will be manifest. Some secretions are accompanied 

 by vaso-dilation ; others by vaso-constriction. Some may per- 

 sist twenty minutes after cutting off the blood supply ; others 

 are paralyzed within two or three minutes. Some are paralyzed 

 by atropine and quinine ; others are not. In the same gland 

 stimulation of one nerve may cause the secretion of a large 

 amount of watery secretion, while stimulation of another nerve 

 causes the secretion of a small amount of exceedingly viscid 

 secretion. There seems, in fact, to be no general rule of secre- 

 tion true for all glands. The great difference between the phe- 

 nomena of different secretions suggests that the mechanisms of 



