46 SCIENCE PROGRESS. 



Kreidl ' has examined the roots of the glossopharyngeal, 

 vagus and accessory at their exit from the medulla to 

 determine in which rootlets these fibres leave the central 

 nervous system. These roots are described by Grossmann ^ 

 as arranged in three groups, which, for convenience of 

 description, bespeaks of as group [a), group (d), and group 

 (c). Group (a) corresponds chiefly to the glossopharyngeal, 

 (d) to the vagus, and [c) to the spinal accessory. 



Kreidl's method consists in dividing one or more of 

 these roots at their exit from the medulla without an- 

 aesthetics and shortly after they have been given a meal 

 consisting of green food-stuffs. The animals (rabbits) are 

 then allowed to recover and given a meal of carrots. In 

 those experiments in which the roots of either groups [d) or 

 (c) had been divided no paralysis of the oesophagus was 

 observed, but where group (a) had been divided the animal 

 soon ceased to eat and the oesophagus was found full of 

 food. This result was constant in over thirty rabbits. He 

 further shows that section of the glossopharyngeal immedi- 

 ately after it leaves the cranium has no influence over the 

 result, and that consequently the fibres after passing through 

 the roots of group {a) pass directly into the vagus. 



Steinach '^ states that in the frog not only does the vagus 

 contain motor fibres for the oesophagus, but that similar 

 ones are present in the posterioT" roots of the second and 

 third nerves. 



Rethi ^ by stimulation of the peripheral end of these 

 roots concludes that the fibres for the tensor palati leave in 

 the motor root of the fifth, for the stylo-pharyngens in 

 group {a) and for the constrictors of the pharynx, the 

 levator-palati, the palato-pharyngeus, and the palato-glossus 

 in group (b). 



Stomach. — In a paper upon the peristaltic contraction of 

 the stomach and intestines, which contains an account of 



1 Pfluger's Archiv, vol. lix., p. 9, 1895. 



2 Ibid., p. I, 1895. 



3 Ibid., vol. Ix., p. 593, 1895. 



* Siiz. d. k. Ak. Wien, vol. ci., Abt. iii., p. 381, 1892. 



