108 



KNOWLEDGE. 



[May 1, 1894. 



Fig. 3. — Front view of full-sized female Hippopotamus, Tiorn 5th NoTember, 

 in the Zoological Gai'dens, London. 



Fortunately, however, paleeontology here once more comes 

 to our aid, showing not only which pair has been lost, but 

 how the loss was brought about. Prom the gravels of the 

 Narbada Valley in central India, which are probably 

 intermediate in age between the Pliocene deposits yielding 

 remains of the Siwalik hippopotamus and the brick-earths 

 of our own country in which occur those of the common 

 African species, there are found two extinct members of 

 the genus, one known as the Narbada hippopotamus 

 {H. namadicus) , and the other as the Indian hippopotamus 

 (H. palaindicm). In the former of these the lower 

 incisors are similar in size and number to those of the 

 Siwalik species ; but in the latter, while the inner and 

 outer pairs are very large, there occurs on each side 



between them a minute and rudimentary 

 tooth, squeezed out from the general 

 line to the upper margin of the jaw, 

 and evidently just about to disappear 

 altogether. We have thus decisive 

 evidence that the missing pair of lower 

 incisor teeth in the common hippo- 

 potamus is the second ; and we further 

 see how a complete transition can be 

 traced, as regards the number of these 

 teeth, from the Siwalik species through 

 the common one to the Liberian hippo- 

 potamus. While it is quite possible 

 that the African hippopotamus may 

 have been directly derived from the 

 Siwalik species, it is quite clear that 

 the pigmy hippopotamus is not the 

 descendant of its giant existing 

 cousin. 



With regard to the geographical 

 distribution of the genus, we have 

 already said that the two living species 

 are confined to Africa, to which it may 

 be added that there is no record of their 

 having ever occurred in the districts 

 lying to the north of the Sahara during 

 the historic period. They are, there- 

 fore, essentially inhabitants of what 

 naturalists term the Ethiopian region, 

 although they are quite unknown in the 

 island of Madagascar, which belongs to 

 the same zoological province. So far 

 as we are aware, there is no evidence 

 that the pigmy species ever ranged 

 beyond its present habitat of Liberia, 

 although the case is very different with 

 regard to the range of the common 

 species. At the present day this animal 

 is found from the Cape Colony north- 

 wards to the cataracts of the Nile, and 

 it extends westwards to Senegal ; but 

 while for several centuries it has been 

 very seldom met with on the Nile below 

 the entrance of the Atbara and Blue 

 Nile, there is abundant evidence that 

 in the time of the Pharaohs it was 

 common in Egypt, where in the temple 

 of Edfu, as well as several other 

 buildings, there are frescoes repre- 

 senting the mode in which it was 

 hunted and speared. That the hip- 

 popotamus is the animal indicated in 

 the book of Job under the name of 

 behemoth is, according to Canon 

 Tristram, undoubted, but there is no 

 evidence that the Jews were acquainted with it otherwise 

 than during their sojourn in Egypt. It is true, indeed, 

 that the writer just mentioned suggests that its range may 

 have extended eastwards as far as Palestine, but this is 

 mere conjecture, and had the creature ever lived there the 

 expeditions which have from time to time explored that 

 country ought to have found some of its remains. In the 

 Pleistocene and upper Pliocene deposits of southern and 

 central Europe there occur, however, numerous remains of 

 a hippopotamus which cannot be specifically distinguished 

 from the existing African form, although it was generally 

 of rather larger size. This difference in size was at one 

 time thought to indicate that the fossil form was a distinct 

 species, but the discovery many years ago of a half 



1872, 



