SECT. II 



PHANEROGAMIA 



601 



171, 194), the vertical position of which 

 contributes to the peculiar habit of the 

 Australian forests. Only the seedlings 

 of these species have a few bipinnate 

 leaves which constantly succeed the coty- 

 ledons. Some American species of Acacia 

 are inhabited by ants (cf. p. 235, Fig. 205) 

 which live in the large stipular thorns 

 and obtain food from Belt's food-bodies at 

 the tips of the pinnules. The plants in 

 this way are protected against the attacks 

 of leaf- cutting ants. Many species of 

 Acacia are of considerable economic value 

 owing to the presence of gums and tannins 



FIG. (531. Floral diagrams of Caesalpiniaceae. 

 A, Cercis sUiquastrum ; B, Tamarindus 

 indica. (After EICHLER.) 



Kic.. r.:i'A Cassia angustifolia. (5 nat. size. After A. MEYER and SCHUMANN.) OFFICIAL. 



