782 Dr. J. BEARD, 



nerve {og) and its division into two portions corresponding to the 

 division of the olfactory organ into the nose proper and Jacobson's 

 organ. The upper ganglion (ogl) belongs to the nose proper, the 

 lower one (ogll) to Jacobson's organ. Zeiss F. oc. 2. 



Plate XXXVII. 



rig. 9. Jacobson's organ in longitudinal vertical section. Lacerta 

 agilis. From an embryo shortly before hatching. It shows very 

 slight signs of the division into ganglionic columns. Zeiss D. 

 oc. 2. 



Fig. 10. A similar section from a similar embryo of Anguis fr agilis. 

 Zeiss D. oc. 2. 



Fig. 11. Section through the region of the still open anterior neuro- 

 pore of a very young lizard embryo, showing the first origin of 

 the olfactory neural ganglionic foundation (ol a n). Zeiss D. 

 oc. 2. 



Fig. 12. Section through the fore-brain region of a very young lizard 

 embryo. Shows the limits of the olfactory neuro - epithelium (s e) 

 and also the olfactory neural ganglionic foundation (olan). Zeiss 

 D. oc. 2. 



Fig. 13. Portion of the nasal epithelium from the same snake embryo 

 as fig. 6. To show the indications of ganglionic columns (sglc) 

 and smell - buds (sb) in the olfactory mucous membrane. Zeiss 

 D. oc. 2. 



Fig. 14. Section through the fore-brain region of a very young lizard 

 embryo, to show the epiblastic origin of the olfactory nerve, i. e, 

 of the olfactory neural ganglionic foundation (ol a n). Zeiss D. 

 oc. 2. 



Fig. 15. Portion of the sensory epithelium of Jacobson's organ from 

 an adult T. natrix. The figure shows the terminal smell - buds 

 (s &) and their ganglionic columns. Zeiss D. oc. 2. 



Plate XXXVIII. 



Fig. 16 and 17. Two di'awings of a section through the fore - brain 

 region of a young Torpedo embryo. To show the origin of the 

 olfactory neural ganglionic foundation {ol a n). Fig. 16. Zeiss F. 

 oc. 2. Fig. 17. Zeiss C. oc. 2. 



Fig. 18. Section of a Torpedo embryo, showing the fusion of the ol- 

 factory neural-ganglion {ol a n) with the neuro-epithelium (s e). Zeiss 

 D. oc. 2. 



Fig. 19. Horizontal section through the olfactory neuro-epithelium of 

 a Torpedo embryo , showing the origin of ganglionic cells (ol g 

 lateral ganglion) from the neuro-epithelium. Zeiss D. oc. 2. 



Fig. 20. Is a low-power drawing of the section from which fig. 18 was 

 taken. Zeiss A. oc. 2, 



