THE INNER LIFE OF PLANTS. 333 



The Drosera^ or sundew of our own bogs, and the Dioncea, or 

 Venus' fly-trap (Figs. 35 and 36) of the North American marshes, in- 

 troduce us to plants wherein the highest stage of carnivorous habit has 

 been attained, and wherein special powers of sensibility and of reflex 

 action have been developed to fulfil the purposes which produced 

 and developed them. We are less concerned with the structure of 

 these plants than with the effects on their habits which that structure 

 is the means of producing. But it will be permissible very shortly to 

 enumerate the modifications which distinguish each species. In 

 both the seat of the modifications is the leaf. That of the sundew is 

 shaped like a battledore, and bears on its surface numerous clubbed hairs 

 or " tentacles," numbering from 150 to 250 on a single leaf. At the tip 

 of each hair is the " gland," and the glistening secretion of these 

 glands has given to the plant its popular name. When such an object 

 as an insect touches the tentacles, these latter close over it, so as to 

 pin it down upon the leaf surface, this process being really a 

 preliminary to the death and digestion of the animal. Moreover, as 

 if strictly imitative of the action of the animal in digestion, the 

 tentacles of the sundew pour forth upon the insect a secretion which 

 not merely, like the gastric juice of the animal, is antiseptic and 

 preservative, but has digestive and solvent properties. In due time, 

 therefore, the nutritive matters contained in the body of the prey 

 are absorbed by the glands, and the organic matter of the animal is duly 

 intussuscepted by the plant, which thus literally reverses the ordinary 

 rule that the plant feeds the animal. That the life of the sundew has 

 become permanently dependent upon this carnivorous habit, is clear 

 from the fact that when insects are excluded from these plants they 

 do not flower so perfectly, nor do they produce the number of seeds 

 found in natural, that is, insect-fed specimens. In the Venus' fly- 

 trap, the broad leaf blade (Figs. 35 and 36) is divided into two halves, 



FIG. 35. LEAF OF VENUS' FLY-TFAP (Open). 



which close after the fashion of a rat-trap, and whose toothed edges fit 

 one into another. The sensitive surfaces consist of three hairs (Fig. 36, 

 a, b) on each half of the leaf, and upon these being irritated in any 

 way, the leaf closes, and, in the case of an insect, imprisons it. When 



