The questions that arise are: Where did the rat-goat come from? How did this utterly peculiar change in a Ruminant's teeth come about? With regard to the second question, it is a matter of importance that although we have hitherto not discovered any Ruminants with this modification of the teeth, still less any cavicorn or sheath-horned Ruminant so altered, yet it is by no means rare amongst herbivorous mammals to find such rat-like teeth making their appearance, whilst the smaller side-teeth of the incisor group or front teeth disappear. The Australian kangaroos and wombats are a case in point--so is the lemur-like aye-aye of Madagascar (an insect eater). So is the Hyrax or "damian" of the Cape, and also the very ancient Plagiaulax from the prae-chalk Purbeck clay. But perhaps the best case for comparison with the ruminants is that of the rhinoceroses. There are a great many species and even genera of fossil and recent rhinoceroses. An old Miocene kind (called Hyracodon) has eight little teeth in the front of the lower jaw. In a Pliocene kind of rhinoceros (called _R. incisivus_) these are reduced to two, the middle two, which are of great size and project far forward--like those of the rat-goat of Majorca. Among living rhinoceroses the Indian species have these two front teeth, but smaller, whilst the square-mouthed African rhinoceros has none at all! This helps us, as a parallel, to understand "the strange case" of Myotragus. But, of course, the rhinoceroses are a distinct line of animal descent--remote from Ruminants. They are (like horses and tapirs) odd-toed hoofed beasts--not even-toed ones, as are pigs, camels, and ruminants. * * * * *