204 Journal of Comparative Neurology. 



PLATE X. 



Fig. g. Transection of the myel in the cervical region near the 3rd (ist 

 ganglionated) spinal nerve, x 22. 



Figs. 10-20. A series of transections through the myel and oblongata, to 

 illustrate its structure and the origin of the cranial nerves ; from a series fixed 

 in Hermann's fluid. The nerve cells are represented necessarily diagrammatic- 

 ally and somewhat enlarged. The metatela is shown merely in outline. 



Fig. 10. Transection of the myel near the second spinal nerve. 



Fig. II. Transection at the beginning of the metatela. x 22. 



Fig. 12. At the level of the exit of the last root of the Vagus nerve, 

 (X'). x 22. 



Fig. ij. At the exit of the first root of the Vagus (X^). x 22. 



Fig. 14. At the level of the glossopharyngeus (IX*+*). x 22. 



Fig. 75". At the entrance of the "dorsal ninth " (IX'+^). x 22. 



Fig. lb. Transection between IX^ and VIII. x 22. 



Fig. ly. At the level of the seventh and eighth nerves, x 22. 



Fig. 18. A portion of a transection in the region of the eighth nerve 

 showing the form and relations of the Mauthner cell, x 42.5 



Fig. ig. A transection between the seventh and fifth nerves, at the divis- 

 ion of the " dorsal seventh " (Vllb) one branch going to the Gasserian gan- 

 glion (Yz Vllb, Fig. I). X 22. 



Fig. 20. At the exit of the fifth nerve, x 22. 



Fig. 21. Transection farther cephalad, at the rising of the lemniscus, and 

 showing the lateral extensions of the metencephal, the hypophysis and saccus 

 vasculosus. X 14+ . 



Fig. 22. Transection at the mesencephalic groove and the entrance of the 

 third nerve. Attention is called to the large cells of the mesencephalic trige- 

 minal nidus and the fibers from the ojfactory region which end in this neighbor- 

 hood. (Tr. olf.) X 14+. 



Fig. 2j. Transection at the transverse commissure showing the epiphysis 

 and the beginnings of the peduncular tracts; also fibers joining them from the 

 thalamus (walls of the diacoele). x 18 + . 



Fig. 24. A transection through the cranium and ear capsules to show the 

 relation of the endolymphatic sac to the brain. The walls of the membranous 

 ear are distorted, the perilymphatic space being very large. Compare Figs, 17 

 and 19. X 8.3. 



Fig. 2j. A portion of a dorsal frontal section to show the paraphysis and 

 the extension of the diaccele simulating a more caudal evagination, lined with 

 cells differing in appearance from those of the paraphysis. x 14. 



Fig. 26. A section slightly farther ventrad than the section shown in 

 Fig. 25. X 9. 



Fig, 27. A frontal section far ventrad, following Fig. 35, Plate XI. It 

 passes through the precommissure and the mesencephalic groove. Just caudad 

 of the mesencephalic groove, fibers are shown decussating ; cephalad of it are 

 fibers from the olfactory lobes, x 6.6. 



