232 THE BOUNDARY-LINE BETWEEN GEOLOGY AND HLSTORY. 



Gradiuilly, in the course of thousands of years, the laud sank, the sea 

 separated parts from it, and a milder temperature prevailed. Theu a 

 portion of the tiora and fauna slowly migrated, partly to tbe mount- 

 ains, partly to the north, and partly to both. Many large animals like 

 the mammoth, incapable of living iu the mountains, remained behind; 

 the lowlands at the lower part of the Ehine's course, which Avere prob- 

 ably the principal abodes of these large herbivorous animals, gradu- 

 ally sank below the present North Sea, so that they, exposed to an un- 

 congenial climate, surrounded by a new immigrated tlora not their orig- 

 inal food, and subjected to the attacks of man, gradually died out. In 

 the lowlands new species continually appeared, many after Ireland and 

 some few after England had already become separated from the conti- 

 nent. Finally came new tribes of men with new arts, and we find the 

 first traces of agriculture. Here the historian takes up the account 

 from the geologist and palseontologist. 



This sketch necessarily remained imperfect, because it was not possi- 

 ble to make it include all the iurther proofs furnished by the study of 

 the present distribution of plants, of lower animals, (land snails,) and 

 especially of marine aninuds. It was also necessary to pass over all 

 those phenomena which relate to the existence of a separate population 

 iu Western Europe. But perhaps what has been said will be snfticieut 

 to give a general idea. 



Defenseless, like no other animal of the same size, man is born with- 

 out sharp teeth, without claws, without any external means of defense, 

 such as the fur of many beasts. The child is dependent a longer time 

 on its mother than the young of any other animal, and no being is as 

 helpless. And yet man has made himself the master of all. He has 

 made a thousand instruments, fire, and the modulations of speech his 

 own. The space of time, which now follows and which is called the Age 

 ef Man, exhibits one great, eiuluring, eminent characteristic — the pro- 

 gressive, irresistible triumi^h of the intellect. 



