I02 



Plants and their Ways in South Africa 



is poured out at the very tips of the leaflets. The ants sally 

 forth in quest of the sweets, but on the way they make the first 

 course of their feast off the marauding leaf-eating insects. 



Insect-eating Plants. — 'I'he Sundew (Drosera) obtains 

 its nitrogen from insects which the plant catches and digests 

 by means of a fluid excreted by the sticky 

 tentacles which are borne on their leaves and 

 stems. 



Utricularia, which grows along the edges 

 of streams or in beds of moss, is another 

 insect-catching plant. Portions of the leaves 

 form little hollow bladders, which help to float 

 the plants when growing in streams. Each 

 and Bennett's leaf has a little trap door opening into the 



" Structural and , , , n at- • i ■ • u 



Physiological Bo- bladder. Mmute anmiais swmimmg by, 

 '^"y"-) easily push in the door and enter. They 



never come out ngain, as pushing the door Irom the inside 

 closes it. Several small animals may be found imprisoned in 

 a bladder at the same time. Why not call Utricularia an 

 insect-harbouring plant ? It has never been ascertained that 

 these small creatures are restive in this confinement. It may 

 be that thev live out the few days of their years in quiet con- 

 tentment, by no means unwilling to yield up their substance 

 eventual!)' to the plants which have harboured them. 



Fig. 86.- -s, Bladdei 

 from a leaf of Ufri- 



4). (From Thonit^- 



