226 



THE CHAIN OF LIFE. 



almost human sagacity, star.d alone, without father or mother, 

 without descent. 



The Rodents, or gnawing animals, appear in the Early Eocene 

 on both continents in familiar forms allied to our Squirrels and 

 Rats. Porcupines and Beavers are added in the Miocene. 

 This group seems thus to have conilnued much as it was; and 

 it is still perhaps represented by as many snecies as at any 

 previous time. Many of the ancient forms were, however, much 



B'lG. 182.— Head of Dinothe7i7t:n f:i;;antcuut. 

 Greatly reduced. Miocene of Eur. pc. 



Kir,. 1 83. — Wing of Vespertilio 

 aquensis. An Eccene Hat. 

 After Gaudry. 



larger than any modern species, and some of these larger forms ' 

 present singular points of approach to very distinct types, as, for 

 example, to that of the Bears ; but these large and composite 

 F^ecie arc long since extinct. The insectivorous mammals 

 have much the same history with the Rodents. Such highly 



^ For example, Tillotherittni of the American Eocene, which was as large 

 as a tapir, and in form resembled a bear. 



