94 yoiirnal of Comparative Neurology and Psychology. 



its course to the nucleus of the same side, which is chiefly situated 

 farther caudad (cf. Figs, c and ci). Another part about as large 

 enters the fasciculus dorsalis, but does not immediately leave it 

 at the other side, but farther caudad like the other motor fibers, 

 as I found in the teleosts and as Johnston also observed in the 

 ganoids. 



Only very few of the sensory fibers end at the place of their 

 entrance. By far the greater part pass backward as the radix 

 descendens trigemini, and its course may be followed through the 

 whole oblongata, decreasing but little in circumference and at the 

 inner side always accompanied by a thin long strand of small 

 cells into which it sends neurites and especially collaterals (Van 

 Gehuchten). In the octavus region it lies farther from the outer 

 surface, as it is covered there by the fibers of the descending 

 octavus and ascending posterior lateralis roots (Figs, c to cv). 

 Behind the most anterior vagus roots, with which the posterior 

 lateralis enters, it approaches the surface again and terminates 

 in the most anterior part of the medulla spinalis in the nucleus 

 Rolandi or nucleus trigemini descendentis, while another part of its 

 fibers seems to run farther caudad (Figs, cvii, cviii). This region 

 has far smaller dimensions in Galeus than in Lophius where a 

 thick spinal root also ends here. 



I was not able, either in Galeus or in Angelus squatina, to be 

 absolutely certain whether or not there is a radix ascend ens trigem- 

 ini. Much more than in the bony fishes I got the impression 

 that there is really such a root (Fig. c, at the right), which ends 

 not far away under the cerebellum. However, since I know that 

 in the teleosts this same impression was given by the course of the 

 secondary communis tract, I am inclined to believe that the tract 

 which gives the impression of being the ascending or cerebellar 

 trigeminus root is, just as in the teleosts, the secondary communis 

 bundle connecting the communis region with the nucleus lateralis 

 cerebelli. As already noticed for the bony fishes. Van Gehuch- 

 ten and C. J. Herrick are of the opinion that we are to deny the 

 existence of this root in the teleosts, nor is it mentioned by Kings- 

 bury. In his latest publication Edinger describes sensory fifth 

 fibers (though without proving their trigeminus relations by 

 degeneration) which ascend into the cerebellum, as Johnston 

 found in the ganoids. Without having undertaken degeneration 

 experiments, I do not venture to pronounce positively in the matter 



