274 THE LIFE OF THE PLANT 



which were supposed to be peculiar to the represen- 

 tatives of this or that kingdom. 



Let us commence with the mode of nutrition. Plants 

 are generally said to feed upon simple inorganic matter : 

 carbonic acid, water, salts ; while animals feed upon 

 complicated organic compounds. Generally speaking 

 this is true, but the rule has nevertheless many excep- 

 tions. For instance, the large class of fungi comprises 

 plants which feed exclusively upon complicated organic 

 compounds, hence these organisms can exist only on 

 soils rich in humus — decomposing organic matter — 

 or else as parasites, feeding upon other organisms. 

 But fungi are not alone in feeding upon ready formed 

 organic matter ; there are parasites also among the 

 highest representatives of the vegetable kingdom. 

 Some of these are lacking in green colouring matter, 

 such as the Dodder (Cuscuta), for instance, which 

 clings to our field plants, like the hop, and lives 

 entirely at the expense of its victim. Others, such 

 as the mistletoe, which attacks oaks, fruit trees and 

 other trees, although capable of independently pro- 

 viding themselves with food, probably also use in great 

 measure substances formed by the plant on which it 

 lives. 



Moreover, modern researches, especially those of 

 Darwin, have acquainted us with a whole series of 

 plants which, though provided with green organs, feed 

 upon animal food and, what is more curious, digest 

 this food in the same way as animals. These are 

 known under the name of insectivorous plants. Here 

 are some examples. The above mentioned catchfly 

 is the most curious of them all. If a leaf of the catch- 

 fly once gets hold of an insect, it does not reopen until 

 it has sucked out of it everything it can, leaving behind 

 a bare insoluble skeleton. A similar experiment can 

 be made by taking instead of the insect a piece of raw 

 or cooked meat, or the hard-boiled white of an egg. 



