88 A NEW THEORY OF EVOLUTION. 



the muscles. If the prey become less abund- 

 ant, more exertion must be expended on its 

 capture. There will be more exercise to 

 develop the muscles, but there will be no 

 more food to sustain them ; and if endurance 

 be developed, it will be at the expense of 

 some other part of the animal economy. 

 Should the struggle for food become intense, 

 the vigour of the strongest must become im- 

 paired, and the weakest perish. And so the 

 experienced hunter of big game knows that 

 where food is scarce he will get little sport 

 and no fine specimens. 



But there is no need to rest our conclusions 

 on hypothetical illustrations. A struggle for 

 existence, on a great scale, has been going on 

 in Australia for the last five years, and forty 

 millions of sheep, it is officially reported, 

 have succumbed in their struggle for food and 

 water. Five years ago there was no struggle 

 for existence on Darling Downs grass and 

 water were there in plenty, and the flocks 

 were as fine as any of their breed. And now 

 the wretched creatures, dying by the way, or 

 selling at a shilling a-head, are the remnants 

 that have survived in the terrible struggle. 

 And how do the fittest of them compare with 

 the flock of five years ago ? Has any bene- 

 ficial variation appeared during the prolonged 



