38 ON PLANTS AND INSECTS. [LECT. 



nectar : the stamens are short ; the pistil, on the con- 

 trary, projects considerably 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 stamens ripen before the pistil, and 

 any flying insect, however small, coming from above, 

 would assist in cross-fertilisation. Creeping insects, on 

 the contrary, which in most cases would enter from 

 below, would rob the honey without benefiting the 

 plant. P. amphibium, as its name denotes, grows 



FIG. 32. Linr.cea. FIG. 33. Carlina. 



sometimes in water, sometimes on land. So long, of 

 course, as it grows in water, it is thoroughly protected, 

 and 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 creeping up to the flowers. In this 

 case, therefore, the plant is not sticky, except just when 

 this condition is useful. All these viscous plants, as far 

 as I know, have upright or horizontal flowers. 



On the other hand, where the same object is effected 

 by slippery surfaces, the flowers are often pendulous ; 

 creeping creatures being thus kept out of them, just as 

 the pendulous nests of the weaver-bird arc a protection 



