XXV] EFFODIENTIA 669 



hair on the upper part of the body is replaced by horny scales like 

 those of Snakes and Lizards, covering the bony plates. 



It is thought that in comparatively recent times, geologically 

 speaking, South America was an island, and just as Australia has 

 preserved some curious animals which could never have held their 

 ground against the powerful Lions and Tigers and Wolves of the 

 Old World, so also in South America evolution seems to have run 

 a course of its own. 



Order II. Effodientia. 



The African group formerly classed with the South American 

 Edentata consists of two genera each representative of a family and 

 both are ant-eaters. The MANIDAE are represented by Manis, the 

 Scaly Ant-eater, which has the hair agglutinated to form overlapping 

 scales, but has no dermal plates and no teeth. This genus is also 

 found in Eastern Asia. M. tricuspis is arboreal in its habits. The 

 ORYCTEROPODIDAE are represented by the Cape Ant-eater, Orycteropus, 

 which has peculiar folded teeth and scanty hair. It is termed by 

 the Boers the Aard-vark or Earth-pig and is nocturnal in its habits, 

 sleeping during the day in burrows which are usually found in the 

 neighbourhood of the large ant-mounds so common on the veldt. 

 The womb and the placenta in this group are of quite a different 

 type from that which is found in true Edentata, and this is one of 

 the main reasons for separating the two groups. In Edentata the 

 two uteri have coalesced to form a single dome-shaped uterus, 

 whereas in Effodientia the two uteri have coalesced only at their 

 lower portions and a forked or "bicornuate" uterus is the result. 



Order III. Insectivora. 



This is a group of small animals which, as their name implies, 

 feed chiefly on insects. They have three or four sharp pointed 

 cusps on each of their back teeth, adapted for piercing the armour of 

 insects, while their front teeth in both jaws are directed outwards 

 so that they act like a pair of pincers in seizing the prey. The 

 Insectivora are plantigrade, that is, they place the whole palm and 

 the whole sole on the ground when they walk (Figs. 336, 337) ; in 

 nearly every case they have the full number (five) of fingers and toes ; 

 they have long flexible snouts projecting beyond the mouth and 

 their brains are of a low and simple structure, the surface of the 

 cerebral hemispheres being smooth, while they leave the cerebellum 



