158 DR. R. BROOM ON 



and has probably very little affinity with the more typical In- 

 sectivores." 



When my paper was written I was in the Karroo, far from any 

 libraries, and I was not aware that in 1864 Peters bad divided 

 the Insectivora into two groups : (A) those with an intestine 

 with a large caecum, including " Galeopitbeci," " Tupayse," and 

 " Macroscelides " ; and (B) those with intestine simple, without 

 caecum, including " Centetinee," " Erinacei," " Talpina," and 

 " Sorices." 



Haeckel in 1866 definitely divided the Insectivora into two 

 suborders: (1) Menotyphla, including the families Cladobatida, 

 with Cladobates and Tupaja, and Macroscelidia, with Macroscelides 

 and Rhynchocyon ; and (2) Lipotyphla, including the families 

 Soricida, Talpida, Erinaceidea, and Centetida. 



Though most later workers have regarded the Insectivora as 

 a single natural group, Leche (1884) has suggested separating the 

 Menotyphla as a distinct order, and Gregory, in his recently 

 published work on 'The Orders of Mammals' (1910), places the 

 typical Insectivora in the Superorder Therictoidea, and the 

 Menotyphla as an order of the Superorder Archonta, together 

 with Dermoptera, Chiroptera, and Primates. 



For some time I have been most anxious to examine the organ 

 in Tupaia to see how far it agreed with Macroscelides, and 

 fortunately I was able to obtain from the American Museum a 

 very good specimen, preserved in formalin, of a young Tupaia, and 

 for comparison a young specimen of Gymnura. Both specimens 

 had been obtained in Borneo by Mr. 0. W. Beebe. Prof. J. P. 

 Hill's laboratory assistant, Mr. F. Pittock, has kindly sectioned for 

 me by microtome the Gymnura snout, but owing to the extreme 

 hardening of the Tupaia specimen the snout had to be cut by 

 hand. Both specimens show all the desired characters satis- 

 factorily. 



The Organ of Jacobson in Tupaia. 

 (Plate I.) 



The nose in Tupaia, unlike that of Macroscelides, does not 

 extend very much in front of the premaxillary bone, and the 

 nostrils are nearly terminal, but look more outwards than 

 forwards. 



A section passing through the nostril shows the nasal cartilages 

 forming a median septum with a well-developed alinasal cartilage 

 above and a small cartilaginous extension forming the nasal floor. 

 A few sections further back, the anterior part of the inferior 

 turbinal is seen in section, attached to the upper part of the nasal 

 wall, and showing the opening of the naso-lacrimal duct on its 

 side. Immediately behind the nostril the inferior turbinal is 

 seen rising vertically from the nasal floor. The nasal-floor 

 cartilage is still attached to the base of the septum but is small, 

 and there is no cartilage in the external wall of the nasal 

 passage. 



