THE NEW EVOLUTION 



of bees and wasps which live in cells carefully pre- 

 pared so as to avoid a loss of moisture, are soft and 

 flabby, more or less like earthworms. 



Compared with the grubs of bees and wasps most of 

 those caterpillars which are the young of butterflies 

 have a thick tough skin, though they nearly all live 

 in more or less humid situations and of course take 

 in water all the time with the portions of the leaves 

 they eat. Many caterpillars, like those of the fritil- 

 laries, conserve their moisture by feeding only in the 

 night time, in the day hiding beneath sticks and stones 

 or among fallen leaves. 



The caterpillars of some of those curious butterflies 

 that feed on ants live in the ants' nests mostly below 

 the surface of the ground. They are soft and their 

 skin is very thin, so that they look much more like 

 the grubs of beetles than they do like the young 

 of butterflies. 



Much as the soft and thin skinned young of house- 

 flies, June-bugs, bees and wasps differ from their 

 parents do the marsh-living and aquatic frogs and 

 salamanders differ from the toads. 



It is the same with plants as with the animals. All 

 the plants on land have some special adaptation to 

 prevent damage through their drying up. In many 

 cases plants flourish in the rainy or the warm summer 

 season and when that passes go into a drought-resist- 

 ing resting stage, or go to seed, the seeds living over, 

 on or in the ground, until the rainy or the summer 

 season comes again. 



Very many insects do about the same. They live 



[46] 



