12 



MORPHOLOGY OF THE 



(VII and YIII) ganglia, can l3e seen extending across the 

 niednllarv wall. Exacth' what these are it is dithcnlt to 

 determine, but it is possible that they may be the developing 

 striiV acusticcP. 



If we now turn our attention to sections cut at right 



angles to the floor of the 

 medulla, at pomts corre- 

 spondmg to the position of 

 each ganglion, we shall find 

 that they would agree with 

 the longitudinal section. 



Figure 8 shows such a 

 section of the V oangHon. 

 The medullary wall is again 

 represented \)\ the fine dots 

 and bounded externally by 

 the Randschleier, the space 

 between lines, and still more 

 externally by the coarsely 

 dotted mesodermic tissue. 

 The pharynx, internal carotid 

 artery, and jugular vein ap- 

 pear in section, and the ir- 

 regularly shaped \ ganglion 

 is seen within the meso- 

 derm. One set of nerve 

 fibres extends from the gan- 

 glion to the Randschleier, but does not enter the medullary 

 wall ; the others extend downward until they meet Meckel's 

 cartilage, and there divide. On the inner side of the gan- 

 fibres are seen extending from the Rand- 



V 



Fig. 8. 



Section of tlie medulla of an em- 

 bryo rabbit 10.8 mm. at right angles to 

 the floor of the fourth ventricle in the 

 region of the V ganglion. T" ganglion. 

 Ep. ependymal layer. Gr. gray layer. 

 Rsch. Kandschleier. Mes. mesoderm. 

 ./. jugular vein. carotid. J/C. Meckel's 

 cartilaue. 



glion certain 



