286 



THE WONDER OF LIFE 



FIG. 46. Acacia Twig (Acacia sphaerocephala), 

 about two-thirds natural size. (After Schimper.) 

 1. The large hollow thorns which are tenanted 

 by ants. 2. An entrance bored through a 

 thorn. 3. Small inflorescence. 4. A compound 

 leaf in resting position. The bodyguard of 

 ants which live in the shelter of the acacia do it 

 no harm. On the contrary they ward off the 

 attacks of the formidable leaf-cutter ants. 



return that 

 they form 

 a b ody- 

 guard, 

 warding off 

 the attacks 

 of other 

 insects. 



An as- 

 soci a t i o n 

 that still 

 requires a 

 good deal 

 of clearing 

 up is that 

 b etween 

 ants and 

 the laby- 

 rinthine 

 stem- 

 tubers of 

 My r m e- 

 codia tuber- 

 o s a ,. ... -a 

 famous 

 Java'n e s e 

 epiphyte. 

 The tuber 

 has many 

 passag'es 

 and cav- 

 erns, which 



