66 SCIENCE PROGRESS. 



upper set of fibres they traced passing through the fourth 

 and fifth anterior lumbar roots, to the sympathetic chain by 

 white rami communicantes, thence by the mesenteric nerves 

 to the inferior mesenteric gangHon, then along the hypo- 

 gastrics to the hypogastric plexus, and so by the vesical 

 plexus to the bladder. The lower set left the cord in the 

 second and third sacral nerves, and reached the hypogastric 

 plexus by the pelvic nerve, and so on to the bladder. 

 Stimulation of either of these two sets caused marked 

 contraction of the bladder. 



Sherrington ^ recorded the movements of the bladder, 

 consequent upon stimulation of the anterior roots of the 

 lumbar and sacral nerves, by means of a water manometer 

 connected to the interior of the bladder by a catheter. 

 In the cat he describes the effective roots, as beino- the 

 third and four lumbar, together with either the second or 

 fifth, or occasionally both. Of the lower set the second 

 sacral was the chief root, and the first and third usually 

 contained fibres havino- this function. In Macacus Rhesus 

 he found the third and fourth lumbar with either the 

 second or fifth, and the second sacral with the first and 

 third to less extent. The lower set always produced the 

 more powerful contraction which was unilateral when a 

 nerve root of one side was stimulated. 



Griffiths ^ found that stimulation of the pelvic nerve 

 produced a more powerful contraction than stimulation of 

 the hypogastric, but that both of them produced contraction 

 throughout the entire thickness of the muscular coat. 

 Stimulation of the nerves on one side produced unilateral 

 contraction of the bladder. Langley and Anderson ^ found 

 that stimulation of either set of nerves caused contraction 

 of the whole muscular coat, but did not get a unilateral con- 

 traction on stimulating the nerves of one side, though the con- 

 traction on the same side was much better marked than on 

 the opposite side. The upper set of fibres left the cord in 

 either the second and third or third and fourth, or fourth 



'^ Joiirn. of Fhys., vol. xiii., p. 677, 1892. 



"^Journ. of Anat. a?2d Fhys., vol. xxix., pp. 61 and 254, 1895. 



^Journ. of Fhys., vol. xix., p. 71, 1895. 



