Wingless Insects unwelcome. 19 



The insects that are armed with a hard covering of 

 chitin are usually winged, and then — supposing of 

 course that they are vegetable feeders — generally reach 

 the flowers by flying. Some of them, however, are 

 wingless, and these, like the snails, etc., can only reach 

 the flower by crawling and clambering over the axis 

 and leaves. These wingless insects are unwelcome to 

 the flowers under all circumstances; and their visits 

 are disadvantageous even if they possess such bodily 

 dimensions, that in pushing to the bottom of the flower 

 they would rub against the pollen and the stigma in 

 due succession. Por such wingless insects, even when 

 they leave a flower laden with pollen, cannot reach the 

 flower of a second stem of the same species till after a 

 long journey and a proportionally long space of iime. 

 A winged insect flies through the air from flower to 

 flower with great rapidity, and often within a few 

 minutes transports the pollen rubbed off from one flower 

 to the stigma of a second, third, and fourth pretty distant 

 one ; whereas a wingless insect must first return from 

 the flower to the ground, and then creep or climb over 

 the axis and leaves of a second stem. N'ow, putting on 

 one side the loss of time which this entails, consider to 

 what dangers the pollen carried by the insect is exposed 

 in this transit ! How easily it may be rubbed off on 



interfere with the floral functions, as that by their presence other 

 insects, whose visits would be of use, are prevented from sucking 

 the nectar. I possess, however, no definite observations on tliis 

 point. 



