书城英文图书英国学生文学读本(套装共6册)
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第212章 CARNIVOROUS PLANTS

I

1.Every one of you,boys and girls,knows that animals eat plants,but it may be something new for you to learn that there are also plants which eat animals.Where,you may ask,shall we look for such cruel and dangerous vegetables?We need not go to foreign lands,for they are to be found in abundance on our own marshes and moorlands.Yet you may take your rambles without any fear of being pounced on and devoured by some “plant of prey.”For they arenot hunters,but trappers,and they only devour such prey as the very smallest insects.

2.Let us go to seek for some of these flesh-eating plants.Here we are on the edge of a wide moor,where the springy turf is pleasant enough under foot in July or August,butquite impass-able with wet during most of the year.The thick carpet of moss is dottedwith clumps of heather,rushes,BUTTERWORTcoarse grasses,and other plants of the moor.Let usnow look more closely at one of those little rosettesof bright yellowish green,which look like vegetable star-fishes scattered over a beach of moss instead of sand.That is one of the plants we want.It is called the butterwort,perhaps because it looks so fat and oily.

3.From the centre of each rosette rises a slenderstalk of two or three inches,bearing a small,duskypurple flower rather like a dog-violet.The green leaves which form the rosette are stiff,and lie close to the ground,as if to keep a clear space among the other plants.They curl up at the edges,and look as if theydid not want to minglewith their kindredroundabout;and indeed they do not want to be troubled with plants creeping over them,for they have other game in view.

4.Attracted by the bright green star,a small insect comes in search of honey.He finds the leaf covered with a sticky fluid,and his touch causes more of the fluid to come out of little pores in the leaf.The insect is held fast,and the gum clogs up the pores of his body so that he cannot breathe.He soon dies.

5.Then the plant pours out an acid liquid,which soon dissolves all the soft parts of the captured in-sect,and leaves only the skeleton.At the same timethis dissolved or digested food is sucked up by the leaf.In fact,by first catching hold of the insect,and then digesting it,this smooth,green leaf really acts both as a mouth and a stomach.

6.If the insect alights near the raised edge of the leaf,that edge curls over,so as to bring him more within reach of the gum and the acid.If you put a little piece of sand on the leaf,the plant will pour out plenty of gum;but it seems to discover that you are playing a trick on it,for it does not pour any acid on the sand.If you give it a bit of flesh or of egg,or even a drop of milk,the digesting acid will be poured out at once.

7.Perhaps you may know that farmers use the acid,or rennet,as it is called,that is got from the stomachof a calf,to curdletheir milk into cheese.The acidjuice of the butterwort is so like the juice of the animalstomach,that in Laplandthe people used to pourwarm milk over some butterwort leaves,and thus changed it into a kind of curd,of which they were very fond.

8.The work of digesting its prey is rather slowly performed by the butterwort,and we should require to stay beside the plant for twenty-four hours or so,to see it completed.When it is finished,the leaf expands again,and lies ready to hold fast and devour any small creature that may come within its grasp.