HOW PLANTS DRINK. 63 



plan millions and millions of years before it was 

 discovered by European farmers. 



Moreover, nature sometimes even goes in for 

 deliberate manuring. Plants like buttercups and 

 daisies, that live in ordinary meadow soils, to be 

 sure, get enough nitrogen and sulphur and other 

 such constituents from the mould in which they 

 are rooted. But in very moist and boggy soils 

 there is generally a lack of these necessary earth- 

 given elements of protoplasm; and natural selec- 

 tion has therefore favoured any device in the 

 plants which grow in such places for obtaining 

 them elsewhere. This they do as a rule by catch- 

 ing insects, killing them, sucking their juices, and 

 using them up as manure for manufacturing their 

 own protoplasm and chlorophyll. Our pretty little 

 English sundew is one of these cruel and perfidious 

 plants (Fig. 10). Its leaves are round, and thickly 

 covered with small red hairs, which are rather 

 bulbous at the end, and very sticky. The bulbous 

 expansions, in point of fact, are small red glands, 

 which exude a viscid digestive liquid. When a 

 small fly alights on the leaf, attracted by the smell 

 of the sticky fluid, he is caught and held by its 

 gummy mass; the hairs then at once bend over 

 and clutch him, pouring out fresh slime at the 

 same time, which very shortly envelops and di- 

 gests him. In the course of a few hours the leaf 

 has sucked the poor victim's juices, and used them 

 up in the manufacture of its own protoplasm. 



Many other insect-eating plants exist in the 

 marshy soils of other countries. One of the best- 

 known is the Venus 's fly-trap of tropical or sub- 

 tropical North America. In this curious plant 

 the leaf is divided into two portions, one of which 



