

54 Actual Races in History. 



requires five months to germinate, to grow and 

 ripen, whereas, in the cold of Finland and Lapland, 

 it accomplishes the same phases of growth in two 

 months. The power of reproduction, also, can 

 vary so much that some roses will bloom two or 

 three times a year; and theie are strawberries that 

 keep in fruit nearly the whole year. 



58. To be quite precise in this matter, we may 

 sum up with Wigand all the known variations or 



modifications under the following heads. 



There are chemical alterations, as in the 

 color, acid, sugar, ethereal oil, etc.; anatomical 

 alterations, as in the covering with hair, texture, 

 thickening of cellular walls, etc.; the physiological 

 function of growth, or enlargement of the entire 

 plant, as well as of each single part, without preju- 

 dice to the essential proportions of form; also the 

 periodical functions of the producing of foliage, 

 the time of blooming, of ripening, of dying; mor- 

 phological variations, in the direction and relative 

 length of the shoots, in the form of leaves, or in 

 the indenting of their edges, in the relative dis- 

 tances of parts, in the number of flowers, etc.; 

 modifications, in short, more numerous . than we 

 care to exemplify. Now, all these changes are 

 actuated, perpetuated, or reduced again, whether by 

 the mere operation of nature, which has been 

 called " natural selection," or by the sagacious de- 

 signing of experimenters, which is much more 

 effective, and is rightly termed " artificial selection." 



