232 



quickness and its recognition of suitable 

 food material. For example, although it 

 will snap shut at the touch of a pencil 

 point, or any other indigestible substance, 

 it soon opens again ; while in the case of 

 a digestible substance the trap remains 

 closed until digestion has taken place. It 

 has been claimed further that when the 

 trap has closed its bristles do not in- 

 terlock closely at first, so that between 

 the crevices very small insects may crawl 

 out and escape. In such an event the 

 trap opens again and waits for other prey. 

 If this be true, it follows that the leaf does 

 not undertake the rather long process of 

 digestion until an insect of suitable size 

 has been captured, one which cannot es- 

 cape through the meshes of the bristles. 

 Digestion is slow work with Dionaea as 

 with an anaconda, being said to occupy 

 not less than two weeks. 



Among the common marsh plants in 

 certain regions are the bladderworts, so- 

 called because their bodies are kept afloat 

 in water by means of numerous little 

 bladders. While these bladders are used 

 in this fashion, they also serve as most ef- 

 fective traps for certain very small water 

 animals related to the insects. Each blad- 

 der has a sort of opening which is guard- 

 ed by a door like that of an ordinary rat 

 trap. From the side of this entrance hairs 

 are floating and waving in the water, and 

 within the transparent bladder are other 

 waving tufts of hairs. For some reason 

 these things are attractive to the minute 

 water animals, and they push aside the 

 easily-moved trap door, and entering the 

 bladder find escape impossible, for the 

 door, which was easy to push aside on en- 

 tering, cannot possibly be moved out- 

 wards. 



It must not be supposed that carnivor- 

 ous plants are peculiar in the kind of food 

 they use, but merely in the source from 



which they obtain it. There are other 

 green plants which supplement their food 

 supply by preying upon other plants. For 

 example, the mistletoe is able to manufac- 

 ture a certain amount of food for itself, 

 but it adds to this supply by absorbing 

 prepared food from the trees upon which 

 it grows. The dodder is another illus- 

 tration of a high grade plant which be- 

 gins life independently, but presently 

 breaks its connection with the soil and 

 becomes entirely dependent upon the 

 plants around which it twines and from 

 which it absorbs. 



A great many plants are known as 

 root-parasites, that is, they absorb from 

 the underground parts of other plants. 

 This is notably the case with the orchids 

 and heaths, which have the appearance 

 above ground of being entirely independ- 

 ent, but which really are quite dependent 

 upon the underground parts of other 

 plants. 



One of the lowest groups of plants, 

 known as the fungi, have cultivated most 

 completely the habit of dependence on 

 other organisms. They attack both plants 

 and animals, and are often exceedingly 

 destructive. Among the better known of 

 these parasites are the rusts, which at- 

 tack and destroy many of our most useful 

 crops. To the fungi there also belong the 

 well-known bacteria, which are the cause 

 of numerous contagious diseases both 

 among plants and animals. It will be ob- 

 served that these parasites are using ex- 

 actly the same sort of food as do the car- 

 nivorous plants. This does not appear 

 so striking in this case, simply because 

 the attacking plants are so much smaller 

 than the organisms attacked that they do 

 not seem to capture them, although they 

 are often none the less effective in de- 

 stroying them. John Merle Coulter. 



MAPLE LEAVES. 



October turned my maple's leaves to gold ; 



The most are gone now ; here and there one lingers ; 

 Soon these will slip from out the twig's weak hold. 



Like coins between a dying miser's fingers. 



Thomas Bailey Aldrich. 



