58 LEAVES FROM THE 



But colour is often a treacherous guide when specific 

 character is the question ; and to say nothing of differ- 

 ences due to sex and age, the alteration of colour in the 

 same individual when its skin is dry, when it is moist, 

 and when the river-horse is taking his subaqueous walk, 

 has been remarked by more than one observer. Le 

 Vaillant, for instance, watched the progress of one at 

 the bottom of Great River, from the top of an ele- 

 vated rock, which advanced into the stream, and he 

 remarked that its colour — which is grayish, he says, when 

 the animal is dry, and bluish when the skin is only moist 

 — as it walked along under the water, appeared to be of a 

 deep blue. After the French traveller had satisfied his 

 curiosity by looking over this unconscious peripatetic, 

 as a certain personage, not to be named to ears polite, 

 is said to look over Lincoln, he watched the moment 

 when it came to the surface to breathe, and killed it 

 with a well-directed bullet, to the great joy of his 

 Hottentots, who, in their surprise at the feat, and delight 

 at the size of the beast, called it, ' The grandmother of 

 the river.' 



In its osteological organization, the hij)popotamus 

 approaches in some degree that of the ox and the hog. 

 The skull, especially, exhibits much similarity in the 

 connexion of its bones, and the figures of its sutures, to 

 that of the Su'idce; but, at the same time, it bears the 

 impress of its own peculiarity. 



The teeth are very remarkable, and, especially the 

 molars, vary much in form, number, and position, accord- 

 ing to the growth and age of the animal. The long 

 subcylindrical incisors, and the canines — the latter being 

 enormous tusks terminating in a sharpened edge, which 

 reminds the observer of that of a chisel — of the lower 

 jaw, give a tenific aspect to the mouth when it is open. 

 This tremendous apparatus, formed principally for tearing 

 and bruising more than grinding, is a fit crushing mill 



