HOG-TRIBE. 543 



observatioQ of the parent Giraffe. She arrived at the Zoological 

 Gardens in May 1836, and was then about eighteen months old, 

 and had all the deciduous series with the first permanent true 

 molars. The two middle deciduous incisors were shed in the 

 month of March 1838, the second incisor on each side in the 

 following July, the first deciduous molars in October, and the 

 second deciduous molars in November and December of the same 

 year. At this time the second true molars come into place. The 

 last true molars began to appear above the gum in August 1839, 

 and the last deciduous molar was replaced by the third premolar 

 before the end of that year : the shedding of the whole deciduous 

 series was completed by the fall of the canines in the female 

 Giraffe at the period of the birth of her second fawn in May 

 1841, when she must have been six years and a half old: the 

 large bilobed crowns of the permanent canines were not completely 

 in place until September 1841. 



The middle incisors are relatively larger in the deciduous 

 than in the permanent series as compared with the buter ones and 

 the canine, in most ordinary Ruminants ; the Giraffe deviates 

 furthest from the typical proportions of these teeth in the superior 

 expanse of the bilobed crown of the permanent canine, but it is 

 interesting to find that the deciduous canine, though its crown is 

 also bilobed, is relatively smaller in proportion to the incisors, and 

 thus shows a less amount of deviation from the common type. 

 The third lobe of the last inferior deciduous molar, in the Giraffe, 

 as in the Sheep and Ox, is relatively larger and retains its central 

 enamel-crescent longer than in the last inferior true molar. This 

 tooth in the great extinct Sivatherium (PI. 133, fig. 3) retained 

 more of the form of its deciduous analogue the last milk-molar 

 than is usually seen in existing species of Ruminantia. 



195. SuidfB. — Of all the natural groups of Ungulata the Hog- 

 tribe offers the greatest diversity of dentition, especially in the 

 structure of the molar teeth : the African Wart-hogs (Phaco- 

 chcerus) rival the Elephants in the relative size and complexity 

 of the last molars, whilst these teeth in the South American 

 Peccaris are simply tuberculate, without increase of size : so 



