146 



SAGACITY AND MORALITY OF PLANTS. 



In other words, this Acacia can afford to provide 

 food and lodging for an army of insects employed 

 to defend it by stinging, instead of elaborating stings 

 of its own and using them, as our common species of 

 Nettles do. Belt mentions several other kinds of 

 plants he came across in Central America, such as 

 a species of Melastoma, of Passiflora, etc., which 

 secrete nectar and provide shelter for ants to defend 

 them against the dangerous leaf-cutting species. 



The most elaborate defences against the de- 

 predations of 

 ants and other 

 "unwelcome 

 guests" are to be 

 found, however, 

 in the crowds of 

 delicate white or 

 coloured hairs, 

 usually arranged 

 in crowded 

 " weels " inside 

 the throats of 

 flowers. Some- 

 times theyspring 

 from the inner 



Fig. 53.— Bog-bean {Mefiyatithes tri/oUata). SUrfaCCS of the 



tubed corollas, occasionally they form a chevaux de 

 frise oxi the base of each stamen ; thus producing a 

 very complex interlacement, which adds much to the 



