ANTS AND VEGETATION. 89 



way account for so wide-spread and invaluable a sense 

 having become permanently lost, in creatures which still 

 roam about and hunt for prey very much as do their 

 fellows who can see. 



Special Relations between Ants and Vegetation. 

 Attention has recently been called to the very remarkable 

 relations existing between some trees and shrubs and 

 the ants which dwell upon them. In the Malay Islands 

 are several curious shrubs belonging to the Cinchonaceae, 

 which grow parasitically on other trees, and whose 

 swollen stems are veritable ants' nests. When very 

 young the stems are like small, irregular prickly tubers, 

 in the hollows of which ants establish themselves ; and 

 these in time grow into irregular masses the size of 

 large gourds, completely honeycombed with the cells of 

 ants. In America there are some analagous cases 

 occurring in several families of plants, one of the most 

 remarkable being that of certain Melastomas which have 

 a kind of pouch formed by an enlargement of the petiole 

 of the leaf, and which is inhabited by a colony of small 

 ants. The hollow stems of the Cecropias (curious trees 

 with pale bark and large palmate leaves which are 

 white beneath) are always tenanted by ants, which make 

 small entrance holes through the bark ; but here there 

 seems no special adaptation to the wants of the insect. 

 In a species of Acacia observed by Mr. Belt, the thorns 

 are immensely large and hollow, and are always tenanted 

 by ants. When young these thorns are soft and full of 

 a sweetish pulpy substance, so that when the ants first 

 take possession they find a store of food in their house. 

 Afterwards they find a special provision of honey-glands 

 on the leaf-stalks, and also small yellow fruit-like bodies 



