280 



EUMTNATION AND SELECTION. 



an actual expansion and contraction of the life-area, as 

 when a continent was rising or sinking, but there would 

 be a virtual expansion and contraction as the power of 

 supporting life in the area was, by changes of climate or 

 other causes, increased or diminished. During good times, 

 varieties which would otherwise be unable to hold their 

 own might arise, and have time to establish tliemsolves. 

 Durin;» bad times, all who were then foitnd unfit would be 

 eliminated. 



That elimination by competition obtains among human 

 folk, needs, alas ! no illustration. Hero, too, there is an 

 alternation of good times and hard times, with effects suffi- 

 ciently marked. The introduction of ostrich-fanning in 

 South Africa alfords a case in point. Tiiis produced good 

 times for the farmers. Whereupon there resulted variation 

 in two directions. Some devoted increased profits to im- 

 provements on their farms, to irrigation works which could 

 not before be afforded, and so forth. For others, increased 

 income meant increased expenditure, and. an easier, if not 

 more luxurious, mode of life. Then came hard times. 

 Others, in Africa and elsewhere, learnt the secret of ostrich- 

 farming. Competition brought down prices, and elimination 

 set in — of which variety need. hard.ly be stated. 



Such, then, are the modes of elimination. Observe that 

 it is a differentiating process. As Darwin says : " It may 

 be well here to remark, that with all beings there must be 

 much fortuitous destruction, which can have little or no 

 influence on the course of natural selection."* The ant- 

 bear swallowing a tongue-load of ants; baltenoptera engulf- 

 ing whole shoals of herrings ; the Greenland whale swallow- 

 ing thousands of fry ; the bear or the badger destroying 



• " Origin of Species," p. 08. 



