On the Cartilago palatina and the Organ of Jacobson in some Mammals. 351 



plicated structure. From the upper wall tvvo cul-cle-sacs projecting 

 npwards are observed. The foremost of these sacs, the blind end 

 of which is directed backwards, opens into the anterior half of the 

 organ. And the other large sac, the blind end of which is directed 

 forwards, opens into the posterior end of the organ. 



As to the histological nature of these cul-de-sacs the foetus 

 examined allows of no sure conclusion. I have not been able to 



Fi- 9. 



Fi- 10. 



C -P s - J.o. 



c.ps. 



Tupaja sp. Foetus (44 mm). Transverse sectious of region of Jacobsons organ; c. cul-de-sac; 

 c.ps. cartilago paraseptalis; y. gland.; J.o. Jäcoeson's organ; »ix. masillary; n.s. nasal septuin; v. blood- 



vessel. x 60. 



observe, in this stage, any distinct difference between the epithelium 

 of the organ and that of these cul-de-sacs. They may be branches 

 of the organ itself; this seems at least to me most probable. 



In the speciniens of Tupaja javanica that I have examined — 

 which are males — I have found no such culs-de-sac. 



From the examination of the organ of Jacobson in Tupaja it 

 appears that this genus has certain primitive characters. As 



