54 SCIENCE PROGRESS. 



tambour. Simultaneous blood-pressure tracings and 

 plethysmographic tracings of other parts, spleen, kidney, 

 etc., were also taken. Thev describe the vaso-constrictors 

 as leaving- the cord from the fifth thoracic downwards. 

 The upper of these supply the upper part of the intestine, 

 duodenum and jejunum, the lower part supplying the ileum 

 and colon. Stimulation of the eleventh, twelfth, and 

 thirteenth thoracic, and first and second lumbar white 

 rami causes a constriction soon followed by a marked dila- 

 tion of the vessel accompanied by a fall in blood pressure. 

 These roots, therefore, contain the chief vaso-dilator 

 fibres. 



Loiver Part of Intestinal Canal. — Fellner,^ in working 

 upon the innervation of the rectum, supports v. Basch's 

 theory that where there is an organ with double muscular 

 wall and double nerve supply, the one set of nerve fibres 

 causes contraction of one muscular layer and inhibition of 

 the second, whilst the other set of nerve fibres exerts the 

 reverse effect. In accordance with this Fellner describes 

 that in the dog stimulation of the nervus erigens causes 

 contraction of the longitudinal and relaxation of the circular 

 fibres of the rectum. Stimulation of the hypogastrics 

 causes the reverse effects. Commenting upon this theory 

 and Fellner's later experiments, Langley and Anderson 

 write :" " We do not wish to assert that this theory applies 

 in no case, but most certainlv it is not one of o-eneral 

 application. x'\ccording to this theory the descending colon 

 of the rabbit should receive from the lumbar nerves no 

 inhibitory fibres for its longitudinal coat, and from the 

 sacral nerves no motor fibres for its circular coat. In fact, 

 when due care is taken inhibition of the longitudinal coat is 

 produced by the lumbar nerves with undeniable distinctness; 

 and the contraction of the circular coat produced by the 

 sacral nerves is, at its best, one of the most striking visceral 

 actions that can be brought about bv stimulatino- any nerve 

 in the body. At the same time we must state that our 



^ Pflilgers Archiv, vol. Ivi., p. 542, 1S93. 

 '^ Jo urn. of Phys., vol. xviii., p. 104, 1895. 



