On Plants and Insects. 163 



alighting on the flower, could scarcely fail to touch 

 the stigma. 



2. The flowers of this species are of a beautiful 

 rosy colour, and are rich in nectar ; the stamens are 

 short ; the- pistil, on the contrary, projects consider- 

 ably above the corolla. The nectar is not protected 

 by any special arrangement of the flower itself, and 

 is accessible even to very small insects. The sta- 

 mens ripen before the pistil, and any flying insect, 

 however small, coming from above, would assist in 



Fig. 58. 



cross-fertilisation. Creeping insects, on the con- 

 trary, which in most cases would enter from below, 

 would rob the honey without benefiting the plant. 

 The Amphibious Polygonum, as its name denotes, 

 grows sometimes in water, sometimes on land. So 

 long, of course, as it grows in water, it is thoroughly 

 protected, and then the stem is smooth ; while, on 

 the other hand, those specimens which live on land 

 throw out certain hairs which terminate in sticky 

 glands, and thus prevent small insects from creep- 

 ing up to the flowers. In this case, therefore, the 



M 2 



