Literary Notices. xxiii 



spinal cord. A.s the terminal nucleus of the cutaneous fibers of the 

 trigeminal nerve is scattered along the whole course of the spinal fifth 

 root in the substantia gelatinosa, so the terminal nucleus of the vis- 

 ceral fibers of the ninth and tenth nerves bears a similar relation to 

 the more deeply lying fasciculus solitarius, with this difference that 

 this nucleus toward its cephalic end is considerably more com- 

 pacted, thus giving rise to the sensory portion of the chief vagus 

 nucleus. 



The new-born mouse is a particularly favorable subject for the 

 the demonstration ot this relation. The author says, referring to the 

 vagus and glossopharyngeal nuclei (p. 44): " There do not exist, 

 therefore, in this animal two sensory terminal nuclei, nor two separ- 

 ate portions for each nerve. A single root common to both nerves 

 proceeds without loss of fibers into the fasciculus solitarius in such a 

 manner that between the upper, or chief, nucleus referred to and the 

 lower, or descending, nucleus there is no distinction aside from that 

 of position." 



To complete the parallel which we have begun, we may call at- 

 tention to the fact, not alluded to by Cajal, that just as the spinal tri- 

 geminal tract runs down into the dorsal horn, so the fasciculus solitari- 

 us runs down into that intermediate zone of the cord which contains 

 Clark's column, the lateral horn and other structures which, following 

 Gaskell, we are inclined to regard as visceral centers To the review- 

 er this parallism, which has been suggested by others also, seems, to 

 be of more than passing importance, especially as it will be found to 

 hold, he believes, throughout the entire vertebrate series. But this 

 brings up the moot question of the homology of the fasciculus soli- 

 tarius and the fasciculus communis of the Icathyopsida, a homology, 

 however, which he regards as established. He would even go farther 

 and suggest that probably the transverse fibers of Cajal's " commis- 

 sural nucleus " of the fasciculus solitarius of the mouse are contained 

 in the " commissura infima Halleri" of the fishes. But these are 

 subjects which he hopes to treat more in extenso shortly. 



c. J. H. 

 The Nervous System of Cestodes.^ 



The worms were killed by immersion in v. Rath's mixture con- 

 sisting of 500 cc sat. picric acid sol., 3 cc. glacial acetic acid, 5 grm. 

 platinic chloride in 5 cc. distilled water, 2 grm. osmic acid crystals. 

 After remaining ten hours they were cut into pieces 3 cm. long and 



* Wm. L. Tower. On the Nervous System of Cestodes. Zool. Attz. 508, 

 1896. 



