ADAPTATION AND SELECTION IN NATURE. 113 



3. Ilistonal Selection, or the selection among the various 

 cells of an organism, conceives the singular notion that 

 within the organism there is a struggle of the parts going 

 on, and certain cells are selected to survive, and relegated 

 to their appropriate region of the organism. This is very 

 much like a civil war, or a fight within a fight, a series of 

 single combats fur pre-eminence. This aspect of a house 

 divided against itself, as Sir William Dawson calls it, is a 

 strange and fanciful one when from such internecine strife 

 is to emerge an harmonious, correlated, and perfect Avhole, 

 such as an organism presents when developed. 



4. Germinal Selection of AVeismann is purely hypothetical, 

 and declares that within the germ, among a host of in- 

 difi'erent variations, there are always present the necessary 

 favourable variations for upward progress, and that these 

 are selected to survive, and form adaptive modifications. 



Of these four forms of selection the fourth may be looked 

 upon as pure hypothesis, and only entertained because of 

 its supplying a mode of thought which may, or may not, fit 

 into an articulated whole. 



3. Histonal selection of Roux is also too vague and 

 supported by too insecure evidence to be of any more 

 importance, except as a suggestion, than that of Weismann. 



2. Sexual selection is obviously applicable only to the 

 higher forms of life in animals, so as a factor in organic 

 evolution it is of minor importance. 



1. Personal or natural selection of Darwin is the real 

 conception which mainly concerns us here, tliough it may 

 be pointed out in passing how great is the importance in 

 the modern world of the sexual form of selection under the 

 guiding hand of man, which is responsible for all the wealth 

 of beauty and utility arising from purpose and intention by 

 man, in artificial selection of plants and animals. 



Selection resembles adaptation in that it has been robbed 

 as far as possible of all purposeful meaning, so much so that 

 it has been applied by Professor Karl Pearson and Sir Norman 

 Lockyer and others to the physical selection of chemical 

 elements composing the heavenly bodies and our own 

 planet, and to so-called "meteoritic evolution," and is in 

 this form considered a leading factor in inorganic evolution. 



In organic existence selection depends on three preceding 

 conditions. Liinng matter, organisms composed of this ; varia- 

 tions among individuals of these organisms ; in addition to the 

 equally momentous condition of appropriate environments. 



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