96 MIND IN EVOLUTION CHAP. 



hollow, and finding the sides too steep to roll it up, 

 whereupon 



" leaving the ball he butted down the sand at one side of the 

 hollow so as to produce an inclined plane of much less angle." 1 



Once again, the beetle's nervous system seems to be 

 lifted out of the class of hereditary mechanisms. 



Of the many contrasts that might be quoted from the 

 bee world 1 will give only one, where the power of adapta- 

 tion and the tendency to mechanical persistence are illus- 

 trated in a single case. 



" Fritz Muller has recorded a singular case bearing on the 

 instinct of these social Insects. He says that a nest of a small 

 Trigona was built in a hollow tree, and that as a consequence of 

 the irregularity of the hole the bees were obliged to give a very 

 irregular shape to their combs of honey. These bees were cap- 

 tured and put in a spacious box (presumably together with the 

 irregular comb, but this he unfortunately does not mention) : 

 after a year, c when perhaps not a single bee survived of those 

 which had come from the canella tree,' they still continued to 

 build irregular combs, though quite regular combs were built by 

 several communities of the same species that he had kept." ' 



Though the bees are not so dominated by mechanism 

 but that they can, at need, adapt their building to the re- 

 quired space, the strength of inertia is still such that the 

 very modification once acquired tends to go on of itself. 



Had we been concerned to disprove that wasps have an 

 intelligent conception of their whole plan of operations for 

 feeding their young, we might have quoted the numerous 

 cases in which they tolerate, or even feed, parasites, which 

 live upon the food which they store up for their own 

 grubs. But we may quote one even stronger case from 

 among ants, whose power of adaptive modification far ex- 

 ceeds that of any other insect. Every one knows the tender 

 care which ants bestow upon their larvae. Yet they freely 

 tolerate in their nest the Lomechusa beetle, the larva of 

 which eats their cherished young. It is as though we bred 

 and tended cattle which habitually devoured our children. 

 Does any one say that this proves the nursing of larvae to 



1 Animal Life and Intelligence, p. 368. 



2 Cambridge Natural History, VI. p. 64. 



