362 A. Ärnbäck Christie-Lmde 



With regard to the further development of the palatal cartilage 

 in the adult animals I have only had an opportunity to examine 

 Sorex aranens. The sickle-shaped cartilago ductus nasopalatini is 

 present, though in a reduced state, but its outer part has no con- 

 tinuation backwards; the cartilago palatina as such has apparently 

 disappeared. And most probably it does not remain in the other 

 adult shrews. 



As to the Chiroptera mentioned above Pteropus sp. and Miniopterus 

 schreibersii are adult specimens, and in them the cartilago palatina 

 is well developed. And Vesperugo noctula figured by Grosser 1 

 is also an adult specimen. 



As to Tupaja I can state nothing at present, having no adult 

 specimen at my disposal. But in a rather old foetus of Tupaja 

 javanica, in which the milk-teeth and the two anterior molars are 

 calcified and about to penetrate the gums, it is present and well 

 developed. 



According to Broom it is not present in the adult Macroscelides 

 proboscideus. 



It may be pointed out that the Prosimiae examined are all 

 young ones and that the cartilago palatina observed in them is very 

 well developed, as appears froni Fig. 14. 



In consideration of the supposed relationship between Tu- 

 pajidae and Prosimiae it is an interesting fact that a well de- 

 veloped palatal cartilage, situated in the same way, is present in 

 both these groups. Of course no decisive conclusion can be drawn 

 from this point of agreement alone, but Tupajidae and Prosimiae 

 have other characters in common, which, together with this one, 

 suggest a genetic connection between them 2 . 



For the present it may be left undecided whether a rudimen- 

 tary palatal cartilage generally occurs in early foetal stages of the 

 mammals or only in certain lower groups. 



Further, it may be an open question, whether this cartilage 

 found in monodelphic mammals still retains some function or whether 

 it is to be regarded as a mere rudiment. 



It most probably plays no part in the formation of the naso- 

 palatine canal. This opinion is supported by the following Observa- 

 tion. In a very young embryo of Tupaja javanica — head-length 



i 0. Grosser, 1. c. Taf. I, Fig. 1. 



2 W. K. Gregory, The Orders of mammals. Bull. Amer. Mus. Nat. Hiat. 

 Vol. XXVII. 1910. 



