INFL UENCE OF NER VO US S YS2"EM. 66 1 



that the increased general blood pressure is powerless to send more 

 blood through or to raise the pressure in the renal capillaries. 



The facts can be equally well explained if we assume that these 

 hidden nerve fibres are vaso-dilator in function an assumption which 

 would be in accord with the numerous other facts we have learnt with 

 regard to the regulation of the urinary flow by the central nervous 

 system. We may conclude, therefore, that the existence of secretory 

 nerves to the kidney is not proved, the subjection of the renal secretion 

 to nervous influences being effected exclusively through the intermedia- 

 tion of the vascular nerves. 



As an additional argument against the dependence of renal secretion 

 on the nervous system, Heidenhain quotes a number of experiments 

 made by Bidder l on frogs, in which the secretion of urine continued 

 normally, although in some animals the whole spinal cord, in others the 

 whole nervous system, with the exception of the medulla, had been 

 destroyed. 



1 Arch.f. Anat. u. PhysioL, Leipzig, 1844, S. 376. 



