Chap. VI] 



ANIMALS 



147 



Of the three last-mentioned cases, that of Triplaris americana, a 

 polygonaceous plant belonging to equatorial South America, and of allied 

 species of the same genus, is the simplest. Hollow axes are frequent 

 in the family. The dwelling, here, as in Cecropia, is by no means an 

 adaptation to ants. On the other hand, the entrance-aperture may safely 

 be described as such. Food-bodies, resembling those of Cecropia and 



Fig. 83. Myrmecophytes. 1. Ficus inaequalis. From the botanic garden, Singapore. 2. On 

 the left : Triplaris americana. Young internodes. From the Buitenzorg botanic garden. On the 

 right : T. caracasana. Old internode. Caracas. 3. Humboldtia laurifolia. From the Buitenzorg 

 botanic garden. All natural size. Drawn by R. Anheisser. 



Acacia cornigera, are wanting, but extra-floral nectaries occur on the 

 leaves. Such extra-floral sugar-secreting glands, quite apart from the 

 flowers and without oecological connexion with pollination, occur very 

 commonly in plants inhabited by ants. 



In Ficus inaequalis, with which may be included a number of plants 

 authentically inhabited by ants, for example species of Duroia, not only 

 the opening but apparently also the hollow chamber has arisen as an 

 adaptation, for the latter is present on some only of the internodes 



L 2 



