Literajy Notices. vii 



Motor Fnnctious of Dorsal Spinal Nerves.* 



The question proposed in this investigation is, " Do the dorsal 

 spinal nerve roots carry functional motor fibres for the splanchnic mus- 

 culature, on the one hand, and on the other hand, for the musculature 

 of the bladder, which is also derived from the lateral plates ?" The 

 investigations of van Wyhe and Hatschek have shown that this is true 

 for selachians, Amphioxus and Ammocoetes ; does it also hold for the 

 higher vertebrates ? 



The dorsal roots of the spinal nerves of the frog were electrically 

 excited with a Du Bois Reymond's apparatus and the results controlled 

 by means of mechanical stimuli of these roots. Such stimulation 

 evoked peristaltic and and anti-peristaltic motions of the digestive tract, 

 and it was demonstrated that the successive pairs of roots correspond 

 to distinct, though not sharply defined successive regions of the diges- 

 tive tract. This result stands in pleasant harmony with the recent work 

 of Sherrington and others on the segmental distribution of the cuta- 

 neous nerves. The innervation is bilateral and the reaction persists after 

 the cessation of the stimulus. The time intervening between the begin- 

 ning of the stimulus and the first noticeable reaction varies ; it is never 

 less than three seconds. These reactions are independent of the vagus 

 or vagus centres. Study of the ventral roots showed that no motor 

 fibres go to the digestive tract from the spinal cord through any of the 

 ventral roots except fibres to the rectum from the sixth and seventh. 

 For the details of the connections of the several roots and of the very 

 interesting relations of the nerves of the rectum and bladder the orig- 

 inal must be consulted. The reader will notice that these results stand 

 in harmony with the anatomical discoveries of Lenhossek and others 

 who have described centrifugal fibres in the dorsal roots. 



C. J. H. 



Spiral Fibres in the Invertebrates.^ 



Ganglion cells are described in the ventral nerve chain of Hirudo 

 medicinalis which are essentially similar to those known in the sympa- 

 thic system of amphibians and reptiles. The spiral fibre breaks up 

 into a reticulum upon the body of the ganglion cell and the author de- 

 scribes this reticulum as consisting of two parts, one extra-cellular, the 



J Steinach, E. and Wiener, II. Motorische Functionen hinterer Spinal- 

 nervenwurzeln. Arch. f. d. ges. Physiologie, LX, p. 539. 



2 Simon, C. Sur I'existence de la cellule k fibre spirale chez les invert^bres. 

 Bibliographie Anat., Ill, 6, Dec, 1895. 



