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. 



18 



