MEDULLA OBLONGATA OF THE RABBIT. 



11 



enter the Randschleier, but which do not penetrate mto 

 the medullary wall. These fibres are reinforced by others 

 from the (VII and VIII) ganglia, and below this point 

 certain fibres are found 



within the medullary 

 wall, as well as in the 

 Randsclileier. 



In a section of this 

 •kind it cannot be de- 

 termined whether the 

 former (within the me- 

 dullary wall) are derived 

 from the V or (VII and 

 VIII) ganglion. It will 

 be seen later, when we 

 examine the cross-sec- 

 tions of this region, that 

 they are really derived 

 from the latter. This 

 band of fibres, from the 

 (VII and VIII) ganglia, 

 enters the medullary 

 Avail, and joins a tract 

 which is derived from 

 the posterior nerve roots 

 of the IX and X ganglia, 

 and which is commonly 

 known as the tractus 

 solitarius. 



Certain other nerve 

 fibres, derived from the 



J 



Fig. 7. 



Section of tlie medulla of an embryo rablnt 

 10.8 mm. parallel to the floor of tlie fourtli ven- 

 tricle. F, ganglion. VT/, 1777, ganglia. X, 

 sections of the IX and X ganglia. TS, tractus 

 solitarius. 07^, otic vesicle. J, jugular vein. 

 J/e5, mesoderm. Ep^ ependymal layer. Gr^ 

 gray layer. Rscli. Randschleier. 



