INHERITA>iCE OF ACQUIRED CHARACTERS loi 



to become smaller — i.e., to germinal variation. It has 

 often been argued that the races of man living in different 

 latitudes are what they are on account of the climatic 

 conditions in which they live. It is true climatic influ- 

 ences have some effect on the organism, as we shall see 

 later, but these are not inherited. How if we turn the 

 argument round, and say only such races survive in certain 

 regions as can acclimatize themselves to the surrounding 

 conditions ? Plenty of evidence could be adduced in 

 support of this contention. We know that white men 

 cannot survive in certain climates, though the black races 

 thrive in the very same regions. 



In short, when a character is inherited it does not follow 

 that it was acquired in the first instance. It may well 

 have been originally a germinal variation. So long as 

 such cases can be explained in this manner, they cannot 

 be one-sidedly adduced as evidence in favour of the 

 transmission of acquired characters. 



[e) Acquirements. 



While in the cases just mentioned we had characters 

 doubtlessly inherited, but originally not acquired, we now 

 deal with phenomena of the reverse order. Here the 

 characters are certainly acquired, but the doubtful point 

 is whether they are inherited. Instances of this kind are 

 furnished by those cases where organisms brought into new 

 surroundings become changed, this change being shared by 

 their offspring. Thus, we have experiments made by 

 Professor Nageli, who transplanted Alpine plants from 

 their original habitat into rich soil at the Munich Botanical 

 Gardens, and found that they changed their appearance, 

 this change continuing for a considerable number of 

 generations. It is well known that sea-plants have certain 

 characteristics, are more hairy than inland plants, and so 

 forth ; that desert plants have thick fleshy leaves to guard 

 against evaporation. Now, though it is true that the 



