THE REIGN OF MAMMALS. 227 



specialised and abnormal forms as the Bats might be supposed 

 to be modern. But, strange to say, they appear with fully 

 developed wings both in Europe and America in the Eocene 

 (Fig. 183). Gaudry thinks that it is *' natural to suppose " that 

 there must have been species existing previously with shorter 

 fingers and rudimentary wings ; but there are no facts to support 

 this supposition, which is the more questionable since the sup- 

 posed rudimcnta.y wings would be useless, and perhaps harm- 

 ful to their possessors. Besides, if from the Eocene to the 

 present,, the Bats have remained the same, how long would it 

 take to develop an animal with ordinary feet, like those of a 

 shrew, into a bat ? 



The F.arly Eocene was not altogether a time of peace in the 

 animal world. The old carnivorous Saurians were dead and 

 buried, but their place was taken by carnivorous mammals, 

 allied to our modern Tigers, Hyaenas, F^oxes, and Weasels. 

 The Carnivora, however, were subordinate in the Eocene, and, 

 as already remarked, some of them appear to be intermediate 

 between marsupial qnd placental forms — a fact which evolu- 

 tionists have noticed with much satisfactior They appear to 

 attain to their culmination in the Miocene, when their powers 

 seem to be proportionate to those of the great and well-armed 

 tjuadrupeds they had to deal with. To this age belongs the 

 introduction of the terrible " Cymetar-toothed Tiger" (Mac/i- 

 airodus^ Fig. 184). Its huge tusk-like canines and power- 

 ful limbs seem to fit it more than any other of the cat family 

 for destructive efficiency. Yet ordinary cat-like animMs were 

 contemporary with it, and have survived it, since Maciiairodus 

 disappears in the Post-Pliocene, though in previous periods it 

 had been very widely distributed on both continents. It is a 

 curious fact, perhaps of more significance in various ways than 

 we yet understand, that the Dog-bear {Arctocyon), of the oldest 

 French Eocene, believed to be the oldest placental mammal 

 known, though technically placed among the Carnivora, has a 

 kind of dnntition indicating that, like the modern Bears, it w'as 



Q 2 



