ARTIODACTYLES 97 



" close time," and, indeed, in many districts it has already been exter- 

 minated. Nor is it looked upon with any favour by the forester, 

 inasmuch as it inflicts serious damage on the trees by tearing off the 

 roots, and destroys plantations made with much care and trouble. It 

 must be conceded, on the other hand, that by incessant burrowing 

 it destroys an immense quantity of injurious insect larvse, and at the 

 same time, by burying underground the fruits of the trees, it brings 

 about involuntarily a sort of natural sowing of the forest. The only 

 one who would regret the total disappearance of this animal is the 

 sportsman, whose great joy it is to bring down with a sure shot a 

 "fine tusker," a full-grown boar. (The female is called "sow." To 

 what uses is the dead animal turned ?) 



Related Species. 



All the species of wild boars multiply very rapidly, and are easily 

 fattened if well fed and kept inactive (compare with ox). They have, 

 consequently, for thousands of years been domesticated by man. By a 

 constant selection of the best animals for propagation, our Domestic Pig 

 (Sus domesticus) has been developed, as well as its many varieties (com- 

 pare the formation of breeds of the dog). In the domestic pig the skull 

 is shorter and higher and the hairs fewer than in the wild boar. The 

 ears are dependent. (How do you explain these deviations ?) The 

 descendants of pigs which have returned to the wild state reassume the 

 form and structure of their ancestral parents (compare with dog and cat). 

 The manifold uses of the pig are too well known to need description. But 

 as the host of the trichina and of the scolex or cysticercus of a tape-worm 

 (Tcenia solium) — " measly " pork — it may become a source of great 

 danger to man. 



A more distant relation of the pig is the Hippopotamus (Hippo- 

 potamus amphibius), an inhabitant of well-watered districts south of the 

 Sahara. As its name implies, its true home is in the water, which 

 it leaves unwillingly and exceptionally. The body, too, is adapted 

 to its generally aquatic habits. Its huge, unwieldy mass can only 

 be moved with any speed or precision in water, which bears a large 

 part of its weight. The disproportionately short legs, which terminate 

 in toes united by webs, serve both as oars and rudders to this colossal 

 creature. The neck, as in all other aquatic mammals, is short. The 

 nostrils, which can be closed, and the eyes and ears, lie high up in 

 the skull, so that the animal needs only to raise the upper part of its 

 immense head above the surface of the water in order to breathe or 

 observe what goes on around it. (Compare what is said in the same 

 respect regarding the Greenland whale, the seal, the otter, and the 



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