540 UNGULATES. 



194. Succession. — The deciduous series of teeth in the Ruminants 

 consists of: — 



. 3-3 1-1 4-4 



m, — ; c. — ; m. — : = 32. 



3-3 ' 1—1 ' 4-4 



The superior incisors and canines are represented in the cavicorn 

 Ruminants and most Cervidcs by minute rudiments imbedded in the 

 gum, and were first observed in the embryos of the Cow and Sheep by 

 Mr. John Goodsir.(l) I have detected similar rudiments of a molar 

 tooth, very near the canines, in the foetus of a Fallow-deer. These 

 rudiments present themselves in the form of minute papillae sunk 

 in depressions of the primitive groove, and, as Mr. Goodsir remarks, 

 *' after the closure of the latter, they remain for a short time as 

 opake nodules imbedded in the gum, in the course of the line of 

 adhesion." They do not attain to that stage of calcification which 

 distinguishes the rudimental hidden teeth discovered by GeofFroy 

 in the gums of the foetal whales. In the Camel tribe, the third or 

 outermost of the upper incisors together with the canine and first 

 premolar, are completely calcified and have permanent successors : 

 in the Musk-deer and the Muntjac the permanent canine attains, 

 as we have seen, unusual size and becomes a formidable weapon ; 

 but the primitive rudiments of the upper incisors and of the first 

 molars in both jaws, disappear without giving origin to the matrices 

 of any successors. The functional and fully developed milk-teeth, 

 commonly found in the Ruminants, are the six incisors and two 

 canines of the lower jaw, and the second, third and fourth molars 

 in both jaws, the first molar being rudimental and not calcified or 

 manifested above the gum except in the Camel tribe. The interest 

 attached to the change of dentition, as indicative of the age of the 

 valuable domestic cattle derived from the Ruminant order has 

 attracted more than usual attention to its successive phases in these. 

 Bojanus(2) has given the most accurate account of these phenomena 

 in the Sheep. The whole of the functional deciduous series, viz : 



0-0 0-0 3-3 



m. — ; c. — : m. — : 



3-3 ' 1—1 ' 3-3 



(1) Report of the British Association, 1839. 



(2) Nova Acta Nat. Curios, torn, .xii, pt. ii, p. 702. 



