226 ORGANIC EVOLUTION CONSIDERED 



the larva feeds on the organic matter which has been 

 prepared in the ball. 



Here we have a series of instincts serving a com- 

 mon purpose. The deposit of the egg in the organic 

 matter, the shaping of this into a ball, the prepara- 

 tion of a hole in the ground, and the moving of the 

 ball into this place of safety, are all done for the 

 benefit of offspring that can never be known to the 

 parent. 



To account for these wonderful instincts, we are 

 told that " necessity is the mother of invention," 

 that the struggle for existence is so severe that the 

 production and preservation of new instincts are a 

 matter of necessity. The fact that the first beetle 

 deposited an egg in such decomposing organic matter 

 by accident was no assurance that the egg would pro- 

 duce a beetle which would repeat the accident. But 

 we must assume that the first deposit of an egg thus 

 made was on account of a new-born instinct which 

 was strong enough to be inherited by the offspring. 

 Strangest of all, however, is the instinct which causes 

 this beetle to move this ball, considerable distances 

 frequently, by standing on its front legs and pushing 

 backwards with its hind legs. These balls are several 

 times as large as the beetles themselves. Sometimes 

 two beetles join in moving a single ball, one pushing, 

 while the other climbs on to the opposite side of the 

 ball, thus disturbing its equilibrium. But moving the 

 ball would be useless to the species unless it were de- 

 posited in the ground in a place of greater safety, so 

 that the instinct to move it and the instinct to de- 

 posit it in a more secure place by digging a hole in 

 the ground must have been evolved at the same time. 

 I see no reason to believe that this could have taken 

 place. It is no argument to say that such changes 

 take place by chance, and that they are preserved 



