in DIGESTION IN THE MOUTH AND STOMACH 201 



venting the cardia from dilating, while excitation of the same 

 region must, on the contrary, provoke a violent and forcible 

 dilatation of the cardia, and reflex emission of the gastric 

 contents. 



Lastly, Muratori's experiments in our laboratory (1909) on dogs 

 with a gastric fistula, through which a long semi-rigid sound (pro- 

 vided with electrodes) can easily be passed to the various regions of 

 the mucous coat of the stomach, show that the whole surface is not 

 capable of exciting reflex vomiting on artificial stimulation with 

 electrical and mechanical stimuli. It is the cardiac region proper, 

 which is distinguished from the rest of the gastric mucous membrane 

 by the property of determining reflex vomiting, the pyloric region 

 being destitute of this capacity. Division of the vagi in the neck 

 abolishes all reflex vomiting, while sensibility to pain remains. 

 These observations of Muratori are not entirely new, Bulatowicz 

 (1858) having noted analogous data. 



The theory of the mode in which the action of the many 

 centres of gastric motion is associated and co-ordinated in the 

 performance of the acts that normally occur in vomiting, has still 

 to be worked out. Certain observations of Openchowski, Tumas, 

 and Ducceschi, however, bear on this question. 



Among the fibres of the vagus coming from the corpora striata, 

 Openchowski (1883) discovered in the rabbit a nerve which, on 

 peripheral excitation, produces contraction of the pylorus as well 

 as dilatation of the cardia. The two antagonistic effects, which 

 are eminently adapted to bring about or favour vomiting, are 

 synchronous. 



Openchowski distinguishes two groups of emetics : those which 

 act directly on the centres, and those which promote vomiting by 

 reflex paths. Apomorphine and lobeline, which belong to the 

 first group, transmit the central excitation through the paths of 

 the spinal cord, so that it is a mistake to consider (as stated in 

 many text-books) that the vagus is the only nerve of vomiting. 

 With emetics of the first group vomiting becomes impossible after 

 the destruction of the corpora quadrigemina ; after division of the 

 cord or its anterior columns to the level of the 5th vertebra ; after 

 section of the thoracic chain of the sympathetic at the height of 

 the 6th and 7th ribs ; after extirpation of the 5th, 6th, and 7th 

 spinal roots ; lastly, after complete separation of the splanchnics. 

 Under all these conditions the characteristic movements of the 

 stomach also come to a standstill. It has hitherto proved impossible 

 to give any adequate explanation of these phenomena. Apomorphine 

 may perhaps paralyse the motor nerve fibres which end in the 

 cardia and upper third of the stomach, with simultaneous excita- 

 tion of the inhibitory fibres, which causes dilatation of the whole 

 cardiac region. 



Valenti saw that interruption of the peripheral sensory paths 



