404 



Mr. D. T. Harris. 



involving vaso-dilator nerves. Measurements of the blood-flow, by Stewart's 

 method, in the hands and feet during fever show that the cutaneous vessels 

 dilate during fall of temperature by crisis. 



"Whether the vaso- dilation of the tongue plays any part in the sensation of 

 taste was not investigated. 



Conclusions. 



1. The lingual nerve contains true vaso-dilator fibres, just as the sympa- 

 thetic contains vaso-constrictor fibres ; both are equally independent of the 

 intervention of metabolites. 



2. No evidence was found that functional hyperemia is due either to 

 diminution in vaso-constrictor tone or to increase in vaso-dilator tone. 



3. The experiments show that the increased blood-supply during muscular 

 activity is due entirely to the products of metabolism; the absence of a 

 simultaneous excitation of the vaso-dilator nerves during voluntary move- 

 ment, though probable, is not proved. 



4. Of the metabolites estimated, C0 2 and «-OH organic acids were found 

 to be increased. 



5. Apart from muscular activity, one function of vaso-dilator nerves 

 was found to be concerned with the control of body temperature ; active 

 hyperemia in the dog's tongue may be induced by reflex excitation of the 

 vaso-dilator nerves through stimulation of heat receptors in the skin.* 



REFERENCES. 



1884. Anrep, V. (senr.), and Cybulski, N., " On the Physiology of the Vaso-dilafcors and 

 Vaso-constrictors," quoted in Hofmann and Schwalbe's ' Jahresber.,' vol. 13, 

 pp. 49-55. 



1912. Anrep, G. V., ' J. Physiol.,' vol. 45, pp. 318-327. 

 1916. Anrep,. G. V., 'J. Physiol.,' vol. 50, pp. 421-433. 

 1920. Anrep and Evans, ' J. Physiol.,' vol. 54 (' Proc.,' p. 10). 

 1910. Asher, L., ' Pfluger's Archiv,' vol. 136, pp. 421-428. 



1914. Barcroft, J., 'The Eespiratory Function of the Blood,' Cam. Univ. Press. 



1915. Barcroft, J., and Kato, ' Phil. Trans.,' B, vol. 206, pp. 149-182. 

 1920. Barcroft and Parsons, ' J. Physiol.,' vol. 53 (' Proc.,' p. 110). 

 1904. Barcroft and Starling, ' J. Physiol.,' vol. 31, p. 491. 



1920. Bayliss, W. M., 'Principles of General Physiology,' Longmans, 3rd edition, 

 pp. 690-707. 



1901. Bayliss, W. M., ' J. Physiol.,' vol. 26, pp. 173-209 ; vol. 26 (Proc. 32) ; vol. 28, 

 pp. 276-299. 



1908. Bayliss, W. M., ' J. Physiol.,' vol. 37, pp. 264-277. 



1852. Bernard, Claude, ' Compt. Rend. Soc. Biol.,' vol. 4, pp. 168-170. 



* Note. — The expenses of this work were defrayed by a grant from the Government 

 Grant Committee of the Boyal Society. 



