On the Cartilago palatina and the Organ of Jacobson in some Mammals. 355 



lower and higher mammals, uniting primitive characters with features 

 found ehiefly in higher mammals. 



Further the occurrence of the rudimentary turbinal makes it 

 probable that the Insectivora (as well as several more mammals 

 which have retained the same character) descend from vertebrates 

 in whieh the organ of Jacobson was of a more complicated struc- 

 ture than is now generally met with in any living mammals, ex- 

 cept Ornitliorhynchiis and Echidna. 



It may also be pointed out that the presence of the cartilaginous 

 outer bar representing the rudiment of a turbinal is an additional 

 low character common to Soricidae and Marsupialia, which, as I 

 have lately shown, agree in important points with respect to the teeth. 



Broom in his paper on the organ of Jacobson in the Marsu- 

 pials 1 finds it manifest that Jacobson's organ »must be a very valu- 

 able factor in the Classification of groups — apparently of more im- 

 portance than even the dentition.« 



However, considering the fact that »we have one type in such 

 dissimilar forms as the Ox, Sheep, Horse, Dog, Cat and Hedge- 



hog « the reason given by the above-mentioned author in 



support of his view seems to me more apt to justify an opinion to 

 the contrary. 



The importance of the organ in phylogenetic respect is, I think, 

 indisputable, but the occurrence of the same type of the organ in 

 widely different groups of animals certainly makes it rather unsui- 

 table as a factor in the Classification of groups. 



On the Cartilago palatina. 



As appears from the above, a rudimentary palatal cartilage is 

 present in Soricidae as well as in Tupaja, and it is better deve- 

 loped in the latter. I have also observed it very well developed 

 in Prosimiae 2 . 



Among the Prosimiae I have had an opportunity to examine 

 three young specimens of Chirogaleus smiihii and a newborn speci- 

 men of Galago demidoffii. In both these species I have observed 

 a small cartilage situated in the same way as in Tiqmja and in 

 other respects showiug a striking agreement with the palatal carti- 



i R. Broom, 1. c. 1896 p. 614. 



2 The raicroscopic preparations of Prosimiae used in this examination 

 belong to the Zootomical Institute of the Univeroity in Stockholm. 



