THEIR RELATIONS. 297 



there is the white insect wax of China produced by the Cicada 

 limbata, made into candles, and paralleled both in quality and 

 use by the tallow-tree, a native of the same empire. For 

 vegetable gums, we have the insect gum-lac; for vegetable 

 dyes, the insect cochineal, galls, and chermes. 



From the above and various other mutual resemblances, let 

 us take a glance now at that obvious and beautiful relation 

 between insects and the vegetable kingdom, which consists in 

 their mutual dependency and use. As one of its most strik- 

 ing examples, we must notice again the appearance of various 

 caterpillars as being generally simultaneous with that of the 

 leaves on which they usually feed, and that of butterflies with 

 the opening of flowers on whose nectar they regale. 



The bee and the blossom are no less evidently of mutual 

 assistance. Everybody knows that the bee could not live 

 without the flower, and every botanist is equally aware that 

 many flowers would become extinct, were not bees and other 

 insects, by the transmission of pollen, to be unconscious agents 

 in their propagation. Besides affording them a supply of 

 food, there is no part of a plant root, stem, bark, leaf, calyx, 

 flower, fruit which does not serve as an abode to many in- 

 sects in one or all of their successive stages. Indeed, without 

 plants, we see clearly that insects would have no existence 

 not even the carnivorous tribes, since even these prey upon 

 vegetable-feeders. The uses, also, of insects to plants, besides 

 that already noticed, though less obvious, may probably bear 



