io8 THE KINGDOM OF MAN 



and survives at the present day in its representatives the 

 African and Indian elephant. One of the European 

 extinct elephants the Tetrabelodon had, we have long 

 known, an immensely long lower jaw with large chisel- 

 shaped terminal teeth. It had been suggested by me that 

 the modern elephant's trunk must have been derived from 

 the soft upper jaw and nasal area, which rested on this 

 elongated lower jaw, by the shortening (in the course 

 of natural selection and modification by descent) of 

 this long lower jaw, to the present small dimensions 

 of the elephant's lower jaw, and the consequent down- 

 dropping of the unshortened upper jaw and lips, which 



FIG. 28. 



The oldest fossil fish known discovered in the Upper Silurian strata 

 of Scotland, and named Birkenia by Professor Traquair. 



thus become the proboscis. Dr. Andrews has described 

 from Egypt and placed in the Museum in London 

 specimens of two new genera one Palceomastodon, in 

 which there is a long, powerful jaw, an elongated face, 

 and an increased number of molar teeth (see figs. 29 

 and 30) ; the second, Meritherium (fig. 31), an animal 

 with a hippopotamus-like head, comparatively minute 

 tusks, and a well-developed complement of incisor, canine, 

 and molar teeth, like a typical ungulate mammal. Un- 

 doubtedly we have in these two forms the indications of 

 the steps by which the elephants have been evolved from 

 ordinary-looking pig-like creatures of moderate size, 

 devoid of trunk or tusks. Other remains belonging to 

 this great mid-African Eocene fauna indicate that not 



