172 STRONG. [Vol. X. 



2d and 3d roots, more dorsal ("nach hintere oder obere ") 

 and originating from the Lobus medullae oblongatae, s. Lobus 

 posterior (which also gives rise to R. lateralis nervi vagi). 

 Fibres exclusively large, some being as large as motor fibres, 

 e.g., those of the oculomotor, and others, in smaller number, still 

 larger. After their exit these roots exhibit no perceptible gan- 

 glionic swelling, but closer investigation shows their fibres to 

 be continuous with bipolar ganglion cells. These roots are 

 non-motor. One goes over into the Trigeminus, the other into 

 the Facialis. 



4th root, " entspringt abwarts von den vorigen etwas mehr 

 aufwarts oder hinterwarts als die erste Wurzel, aus der Seite 

 der Medulla oblongata." Fibres fine and ganglionated, but not 

 so apparently connected with ganglion cells, which are seldom 

 bipolar. Non-motor. A part goes over to the Trigeminus, a 

 part to the Facialis, and a part composes the bulk of the R. 

 palatinus. 



5th root, smallest, furthest caudad, issuing immediately in 

 front of the first acoustic root. Fibres exclusively large. 

 Motor. Goes over entirely into the Facialis. 



In Raja, according to Stannius, we have only three roots, 

 which closer examination resolves into four, inasmuch as roots 

 3 and 4 of bony fishes are in close apposition. 



1. Emerges in two strands, is composed of fibres of various 

 size and also of mixed functions, the motor fibres being in the 

 ventral part. This root corresponds to root i of bony fishes. 



2. Emerging close to VIII, principally from corpus resti- 

 forme. Part goes over into V and part into VII. Fibres are 

 partly broad and partly half as broad. Some of the fibres are 

 motor, which belong to the VII exclusively. 



3. A large "hintere oder obere" root, arising above the 

 preceding, of broad fibres and non-motor. A part mingles 

 with 2 and part goes over into the V. 



Stannius summarizes as follows : 



Root I. — Motor and sensory. Fibres mixed. Belongs to the 

 Trigeminus proper. Sometimes divided. 



Root II. — Non-motor, ''hintere," sometimes single, some- 

 times divided. From corpus restiforme. Only broad fibres 



