64 SCIENCE PROGRESS. 



a few being found in the third and fourth, and tenth and 

 eleventh anterior thoracic roots. The nerves to the hepatic 

 artery have been investigated by Cavazzani and Manca.^ 

 Their method was to establish an artificial circulation and 

 then determine the amount of outflow under different 

 circumstances. They find vaso-dilators in both the 

 splanchnic and vagus, and constrictors in the splanchnic. 

 Asphyxia causes a dilation which is not produced when the 

 vagi are cut. Stimulation of the coiliac plexus low down 

 causes better dilatation than stimulation of the vasfus. 



I nnervation of the Thoracic duct. — By determinations 

 of the rate of outflow of a fluid at constant pressure passing 

 through the Thoracic duct, Camus and Gley^have obtained 

 evidence of the presence of nerves, causing both dilation 

 and constriction of the duct, in the sympathetic chain under 

 the first thoracic ganglion. As a rule the dilator effect is 

 produced. 



NERVES TO THE GENITO-URINARY SYSTEM. 



To the kidney. — Bradford^ has determined the origin of 

 the vascular nerves to the kidney by observations of the 

 changes in its volume on excitation of the various anterior 

 roots. He finds that thevaso-constrictors are mainly contained 

 in the eleventh, twelfth, and thirteenth thoracic nerves, to a 

 less extent in the seventh, eighth, ninth, and tenth thoracic, 

 and sometimes in the sixth thoracic and fir&t and second 

 lumbar nerves. He determined the presence of vaso- 

 dilator nerves by stimulating with induced shocks, repeated 

 only once per second, or once in two seconds. By this 

 method he was able to show the existence of dilator fibres 

 to the kidney in the eleventh, twelfth, and thirteenth 

 thoracic nerves. 



Langley and Dickinson ^ have shown that the nerve 

 cells on the course of the constrictor fibres are situated in 

 the coeliac, mesenteric, or renal ganglia, and that the cells 



^ Arch. Ital. de Biol., vol. xxiv., pp. 33 and 295, 1895. 

 '^ Arch, de Physiol., vol. vii., pp. 301, 328, 1895. 

 ^ Journ. Physiol., vol. x., p. 358, i88g. 

 ^ Proc. Roy. Soc, vol. xlvi., p. 423, 1889. 



