Parasites — continued. 



Fig. 15. This is a case where the antenna wao caught by a gland, and it would appear that the insect is bound hand and foot, 

 as it were, by the inner, shorter tentacles and the outer, longer tentacles gradually fold over and seal its doom. 



There are two ways in which a plant may feed, either by taking in inorganic substances and converting them into the organic 

 material of which it is already composed, or by taking in organic materials and working them up into its own substance. 



The first mode is that adopted by plants possessed of chlorophyll, or an allied colouring matter. This chlorophyll is commonlv 

 regarded as a carbonic-acid decomposing-apparatus ; but quite recently it has been suggested that it is the living protoplasm underlying 

 it which performs this work, while chlorophyll merely serves to mask it, and prevent too rapid action in the presence of sunlight. In 

 this case chlorophyll would be an accompaniment, and not the cause, of decomposition. 



The second mode is carried on by plants without chlorophyll, or an equivalent colouring matter; and, as already pointed out, living 

 green plants or animals may be preyed upon, in which case the attacking plants are Parasites ; or dead and decayed organic bodies may 

 be used, when they are Saprophytes. 



Starting with the ordinary Green Plants, every stage of Degradation may be traced. 



The Mistletoe is only partially parasitic, since it bears green leaves, but the Dodder is wholly parasitic. It forms little discs in 

 contact with the stem of the plant it has attacked, from the centre of each of which a rootlet is emitted, and penetrates into the tissues 

 of its host. 



Then the next step is from living to decayed matter, as in the case of the brown Bird's-nest Orchid, which absorbs the liquified 

 decaying leaves amongst which it lives. The Bladderwort, too, absorbs the decayed animal matter, putrifying in its bladders. 



But a further stage is reached when the plant is able to bring its food-materials into a state of solution as well as to absorb them, 

 and this is accomplished by the Butterwort and the Sundew, which have not only beautiful contrivances for catching their living prey 

 but means for digesting it as welL 



