FOLLICULAR STAGE OF DENTITION IN THE RUMINANTS. 53 



II.— ON THE FOLLICULAR STAGE OF DENTITION 

 IN THE RU^riNANTS, WITH SOME REMARKS 

 ON TILVT PROCESS IN THE OTHER ORDERS 

 OF ]\IAMMALIA. 



Since the meeting of the British Association in 1838, at wliich 

 the paper on the development of the human teeth was read, 

 I have detected the follicidar stage of dentition in the pig, 

 rabbit, cow, and sheep, but have not had an opportunity 

 of examining it in those animals in which observations 

 would have been most valuable. I have been able to 

 verify, what was at that time stated as probable — viz. that 

 all the permanent teeth, with the exception of the first molar, 

 which does not succeed a milk-tooth, are developed from the 

 internal surface of cavities of reserve, and that the depending 

 folds of the sacs of composite teeth are formed by the lips of 

 the follicles advancing inwards after closure of the latter. In 

 tracing the progress of development of the pulps and sacs 

 of the teeth in the cow and sheep, from their first appear- 

 ance, as minute as possible, on the full surface of the 

 membrane of the mouth, or on the internal surface of the 

 cavities of reserve, till they have acquired their ultimate 

 configuration, I have to announce the fact, that at an 

 early period of the embrj'onic life of these animds they 

 possess the germs of canine and superior incisive teeth ; 

 the former existing as developed organs in two or three 

 genera only of ruminants, the latter being found in the 

 aberrant family of camels. The.^e germs present them- 

 selves under the form of slight dunples in the primitive 

 groove, and after the closure of the latter, tlu-y remain 



