364 COSMOS. 



the combined action of many different internal, as well as 

 external conditions, the nature of which cannot in all cases 

 be defined, the most striking varieties being found in those 

 families which are capable of the greatest distribution over 

 the surface of the earth. The different races of mankind are 

 forms of one sole species, by the union of two of whose mem- 

 bers descendants are propagated. They are not different 

 species of a genus, since in that case their hybrid descendants 

 would remain unfruitful. But whether the human races have 

 descended from several primitive races of men, or from one 

 alone, is a question that cannot be determined from expe- 

 rience."* 



Geographical investigations regarding the ancient seat, the 

 so-called cradle of the human race, are not devoid of a mythical 

 character. " We do not know," says Wilhelm von Humboldt, 

 in an unpublished work, On the Varieties of Languages and 

 Nations, " either from history or from authentic tradition, 

 any period of time in which the human race has not been 

 divided into social groups. Whether the gregarious condition 

 was original, or of subsequent occurrence, we have no historic 

 evidence to show. The separate mythical relations found to 

 exist independently of one another in different parts of the 

 earth, appear to refute the first hypothesis, and concur in 

 ascribing the generation of the whole human race to the union 

 of one pair. The general prevalence of this myth has caused 

 it to be regarded as a traditionary record transmitted from 



submerged bed of the (shallow) Meiocene Sea. This great flora, in the 

 epoch anterior to, and probably in part during the glacial period, had 

 a greater extension northward than it now presents. 9. The termina- 

 tion of the glacial epoch in Europe was marked by a recession of an 

 Arctic fauna and flora northwards, and of a fauna and flora of the 

 Mediterranean type southwards ; and in the interspace thus produced 

 there appeared on land the Germanic fauna and flora, and in the sea 

 that fauna termed Celtic. 1(X The causes which thus preceded, Jlw 

 appearance of a new assemblage of organised beings, were the~3estruc- 

 tion of many species of animals, and probably also of plants, either 

 forms of extremely local distribution, or such are were not capable of 

 enduring many changes of conditions, species, in short, with very 

 limited capacity for horizontal or vertical diffusion. 11. All the changes 

 before, during, and after the glacial epoch, appear to have been gradual, 

 and not sudden ; so that no marked line of demarcation can be drawn 

 between the creatures inhabiting the game element and the same locality 

 during two proximate periods."] TV. 



* Joh. Miiller, Physiologic des Menschen, bd. ii. s. 768. 



