154 A STRANGE EXTINCT BEAST 



close to each other, very large, and each with a tremen- 

 dously long, deeply set root. They meet a similar pair ot 

 teeth in the upper jaw, and give the hare, rabbit, rats, 

 mice, beavers, and porcupines the power of " gnawing " 

 tough substances. These animals are hence called Rodents, 

 or gnawers, and the two great front teeth are called " rodent- 

 teeth." No arrangement of teeth could be much more 

 unlike than are the group of eight little chisel-like teeth of 

 the lower jaw of the Ruminants and the two enormous 

 gnawing teeth of the Rodents. Apparently the two rodent 

 incisors, or front teeth, of the lower jaw of the rat corre- 

 spond to the two middle incisors of the Ruminant's lower 

 jaw ; the other front teeth of the Ruminant have atrophied, 

 disappeared altogether. The rodent condition has been 

 developed from that of an ancestor which had several front 

 teeth and not two large ones only ; but we have not at 

 present found the intermediate steps. 



The reader should compare the teeth of the goat and 

 the large rat here pictured with the more typical and 

 complete series of the pig, given in Fig. 15, p. 140. The 

 pig's teeth are the same in number as those of the 

 ancestral primitive typidentate mammal, and their form is 

 near to that of the ancestor's teeth. 



Now I come to the extraordinary interest of Miss Bate's 

 goat-like or antelope-like animal from Majorca. Although 

 it is shown by its skull (Fig. 25) and other bones to be 

 distinctly one of the sheath-horned ruminants, very like a 

 small goat or antelope, the lower jaw, of which there are 

 several specimens, does not present in front the little group 

 ^f eight small chisel-like " cropping " teeth, but, instead, two 

 enormous rodent teeth placed side by side, very deeply 

 fixed in the jaw, and quite like those of some rat-like 

 animals in shape. Hence the name given to this little 

 marvel by Miss Bate "Myotragus," "the rat-goat." This 

 strange little animal also differs from goats and antelopes 



