TROPICAL NATURE 



are always accompanied by flocks of insectivorous birds, who 

 prey upon the winged insects that are continually trying to 

 escape from the ants. They even attack wasps' nests, which 

 they cut to pieces and then drag out the larvae. They bite 

 and sting severely, and the traveller who accidentally steps 

 into a horde of them will soon be overrun, and must make 

 his escape as quickly as possible. They do not confine them- 

 selves to the ground, but swarm up bushes and low trees, 

 hunting every branch, and clearing them of all insect life. 

 Sometimes a band will enter a house, like the driver ants in 

 Africa, and clear it of cockroaches, spiders, centipedes, and 

 other insects. They seem to have no permanent abode, and to 

 be ever wandering about in search of prey, but they make 

 temporary habitations in hollow trees or other suitable places. 

 Perhaps the most extraordinary of all ants are the blind 

 species of Eciton discovered by Mr. Bates, which construct a 

 covered way or tunnel as they march along. On coming 

 near a rotten log, or any other favourable hunting ground, 

 they pour into all its crevices in search of booty, their 

 covered way serving as a protection to retire to in case of 

 danger. These creatures, of which two species are known, 

 are absolutely without eyes ; and it seems almost impossible 

 to imagine that the loss of so important a sense-organ can be 

 otherwise than injurious to them. Yet on the theory of 

 natural selection the successive variations by which the eyes 

 were reduced and ultimately lost must all have been useful. 

 It is true they do manage to exist without eyes ; but that is 

 probably because, as sight became more and more imperfect, 

 new instincts or new protective modifications were developed 

 to supply its place, and this does not in any way account for 

 so widespread and invaluable a sense having become per- 

 manently 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 Cinchonacese, which grow 

 parasitically on other trees, and whose swollen stems are 



