INSECTS 



419 



year the new queen lays eggs, from which emerge Polyergus workers, and these 

 eventually obtain the mastery of the nest. 



The great majority of the numerous kinds of ants inhabiting the flooded lands 

 of the valley of the Amazon make their nests in trees, so as to be above the water 

 level. Among these some of the most remarkable are the long, pendent, skein-like 

 nests of Azteca barbifex, the torpedo-like structure formed by a species of Campo- 

 notus, and the sheet-like papier-mache nest of A. trigona. Fungus-growing ants 

 are very abundant, their presence being generally indicated by the crater-like 

 elevations leading to the subterranean chambers in sandy districts of certain parts 

 of the country. To these the ants bring fragments of leaves from long distances, 

 and, after storing them in the subterranean chambers, use them as hot-beds for the 



LONG-ARMED WHIP-SCORPION. 



cultivation of the mycelium stage of the fungns Rhozites gongulophora. Whether 

 the fungus, in its fully developed state, ever reaches the surface through one of the 

 entrance-tubes is a point which has not yet been definitely determined. 

 Whip-scorpions Among the Arachnida of South America is the curious long- 



and Spiders, armed whip-scorpion (Tarantula, or PJ/rynus, reniformis), armed 

 with pincers an inch in length. It belongs to a family, Tarantulidce, of which the 

 typical section, containing three genera, is exclusively tropical American and 

 West Indian, while the other two sections are Old World. The spiders include 

 the large bird-catching forms, such as Avicularia, or My gale, vestiaria, whose 

 bodies are clothed with coarse hairs and bristles. The members of the genus 

 Avicularia are exclusively tropical American, as ai*e those of the allied Eury- 

 pelma. Their nearest relatives are the Indian Poecilotheria, and the West 

 African Scoclra. 



Although the fact that these giant spiders ascend trees at night to suck the 



