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 vege- 

 table 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 striking 

 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 as- 



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sistance. 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 manv insects in 



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one or all of their successive stages. Indeed, without plants, 

 we see clearly that insects could 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 a greater proportion 



