92 Proceedings of the Royal Society of Victoria. 



in the length of this wall, the gland ducts pass through to open 

 into the tube, the last part of their wall being lined by a 

 continuation of the sensory epithelium. 



The space between the Organ of Jacobson and the cartilage of 

 Jacobson, or the bone of the crista nasalis, is closely packed in its 

 upper half with nerve fibres (Fig. 6, n.f.). These are much 

 more numerous in the median and posterior portion of the wall, 

 decreasing in quantity anteriorly. At the hinder end of the 

 tube, a large bundle passes off to run in the septal mucous 

 membrane until finally it joins the main olfactory trunk. I 

 have been able to trace these fibres among the cells of the 

 sensory layer, but not actually into the cells, where doubtless 

 they do end. As the nerve fibres decrease in number their place 

 is taken by glands. The cavernous tissue {c.t.) so conspicuous 

 in Klein's figures of the lateral wall in the Guinea-pig^ and 

 Rabbit, '^ and much more rudimentary in the median wall of the 

 Dog,' is very abundant in the lower half of the median wall in 

 Notoryctes. Here there are one or two arteries and several 

 somewhat large veins forming a plexus, and supported by 

 ordinary loose fibrous tissue. In the position of the nerves and 

 veins in this median wall, we may compare this with Phasco- 

 lomys.' In Notoryctes, as previously stated, the distinction 

 between the medial and the lateral epithelium persists right to the 

 posterior end of the Organ, as contrasted with the Rabbit, where 

 only columnar epithelium is found at the posterior end of the 

 Organ, and with Phascologale^ and with Macroscelides.^ 



Jacobson's duct, as heretofore described, is extremely short, 

 and is lined by a continuation of the ordinary nasal epithelium 

 similar to that of the lateral wall. This is to be contrasted with 

 the ordinai-y marsupial, e.g., Dasyurus,' in which Jacobson's duct 

 is lined with squamous epithelium. 



Stenson's duct, however, is lined by stratified pavement 

 epithelium continuous with that lining the palate. The surface 



1 Q.J. M.S., vol. xxi., pi. vii., fig. 5, pi. xvii., fig. 6. 



2 Loc. cit., pi. XXX., fig. 5-8. 



3 Loc. cit., vol. xxii., pi. xxvi., figs, 14, 15. 



4 Proc. Linn. Soc. N.S.W., vol. xi., n.s., 1896, 614. 



5 Proc. Linn. Soc. N.S,W., vol. xi., n.s., p. 594. 



6 Proc. Zool. Soc, 1902, vol. i., p. 226. 



7 Proc. Liun. Soc. N.S.W., vol. xi., n.s., 1896, p. 595. 



