INDIRECT BENEFITS DERIVED FROM INSECTS. 205 



to which they find the necessity of themselves conveying pollen from a 

 male flower, when the early season of the year precludes the assistance of 

 insects. Sprengel asserts that, apparently with a view to prevent hybrid 

 mixtures, insects which derive their honey or pollen from different plants 

 indiscriminately will, during a whole day, confine their visits to that species 

 on which they first fixed in the morning, provided there be a sufficient 

 supply of it^ ; and the same observation was long since made with respect 

 to bees by our countryman Dobbs.^ 



Thus we see that the flowers which we vainly think are 



" bom to blush unseen, 



And waste their fragrance on the desert air," 



though unvisited by the lord of the creation, who boasts that they were 

 made for him, have nevertheless myriads of insect visitants and admirers, 

 which, though they pilfer their sweets, contribute to their fertility. 



I am, &c. 



' Willd. Grundriss, 352. * Phil. Trans, xlvi. 536. 



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