tion, or rather over-reproduction, is a universal character- 

 istic of living things. The normal rate of multiplication 

 is such that any given form of animal or plant would 

 cumber the earth or fill the sea in a relatively brief period 

 of time. We now know that a bacillus less than %ooo of 

 an inch in length multiplies under normal conditions at a 

 rate that would cause the offspring of a single individual 

 to fill the ocean to the depth of a mile in five days. "Slow- 

 breeding man," wrote Darwin, "has doubled in the past 

 twenty-five years." But excessive multiplication is checked 

 by the third part of the whole process, namely, the struggle 

 for existence, that fierce unequal warfare waged by every 

 individual with its inorganic surroundings, with other 

 species of living things, and with others of its own kind. 

 Indeed where members of the same species compete, the 

 struggle often surpasses in ferocity the warfare with other 

 organisms. Communal organisms only are in part excep- 

 tions, for in these the battle involves the clash of com- 

 munity with community more than it does the interests of 

 the individuals of a single colony. To what, now, do these 

 elemental processes lead, asks Darwin. Though all seek 

 to maintain themselves, all cannot possibly live when only 

 a few can find sustenance or can escape their enemies. 

 Naturally those which possess any advantage whatsoever, 

 that vary ever so slightly in the direction of better adjust- 

 ment would survive where their brethren perish. And this 

 is nature's selective process, with its positive and negative 

 aspects the survival of the fittest and the elimination of 

 the unfit. Now we can see why adaptation is a universal 

 characteristic of species there are no unadapted. If 

 such there were, they have fallen long ago, and the world 

 knows them no more. True it is that perfection is not 

 attained by any creature, but it must establish a modus 

 Vivendi or it perishes. Thus, Darwin held, nature perfects 

 species by dealing directly with favoring derivations that 



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