66 THE STORY OF THE PLANTS. 



is highly developed in certain American and Asi- 

 atic marsh-plants. The leaves of teasel grow op- 

 posite one another, joining the stem at the base, 

 so as to form between them a sort of cup or basin, 

 which will hold water. If you look close into this 

 water you will find that it is often full of dead 

 midges and ants ; and the plant puts forth long 

 strings of living protoplasm into the water, which 

 suck up the decaying juices of these insects, and 

 use them for the manufacture of more protoplasm 

 and chlorophyll. In this case, water is used both 

 as a trap and as a solvent ; the insects are first 

 drowned in the moat, and then allowed to decay 

 and digest themselves in it. 



Teasel, however, is but a simple example of 

 this method of insect-catching. Several American 

 marsh-dwellers, collectively known as pitcher- 

 plants^ carry the same device a great deal further. 

 They are far more advanced and developed water- 

 trap setters. The Canadian side-saddle plant allures 

 insects into its vase-shaped leaves, which are filled 

 with sugar and water. This is just the same plan 

 which Ave ourselves employ to catch flies when we 

 trap them in a glass vessel by means of a sweet- 

 ened and sticky liquid. The pitchers are formed 

 by leaves which join at the edges; they are at- 

 tractively coloured, so as to allure the flies; and 

 they secrete on their walls a honeyed liquid, which 

 entices the victim to venture further and further 

 down the fatal path. But the inner sides of the 

 vase are set with stiff downward-pointing hairs, 

 which make it easy to go on, but impossible to 

 crawl back again. So the flies creep down, eating 

 away at the sticky sweet-stuff as they go, till they 

 reach the bottom and the hungry water, when they 

 fall in by hundreds, and are drowned and digested. 



