188 HYMENOPTERA. 



metres,* and their depth varies from one to two metres. 

 Very many openings, of a diameter of about one to three in- 

 ches, are contrived from the exterior, and conduct to the inner 

 cavities which serve as storehouses for the eggs and larvae. 

 The central part of the nest forms a sort of funnel, designed 

 for the drainage of water, from which, in a country where 

 the periodical rains are often abundant, they could hardly es- 

 cape without be- 

 ing entirely sub- 

 merged, if they 

 did not provide 

 for it some out- 

 let. 



"The system 

 which reigns in 

 Fig. 119. the interior of 



these formicaries is extreme. The collection of vegetable 

 debris brought in by the workers is at times considerable ; 

 but it is deposited there in such a manner as not to cause any 

 inconvenience to the inhabitants, nor impede their circulation. 

 It is mostly leaves which are brought in from without, and it 

 is the almost exclusive choice of this kind of vegetation which 

 makes the (Ecodo^a a veritable scourge to agriculture. At 

 each step, and in almost every place in the 

 elevated woods, as on the plains ; in desert 

 places as well as in the neighborhood of 

 habitations, one meets numerous columns 

 of these insects, occupied with an admirable 

 zeal in the transportation of leaves. It 

 seems even that the great law of the divi- 

 Fig. 120. sion of labor is not ignored by these little 



creatures, judging from the observations which I have often 

 had occasion to make." (Sumichrast.) 



"The (E. cephalotes" says H. W. Bates, "from its immense 

 numbers, eternal industry, and its plundering propensities, be- 

 comes one of the most important animals of Brazil. Its immense 

 hosts are unceasingly occupied in defoliating trees, and those 

 most relished by them are precisely the useful kinds. They 



* A metre is about thirty-nine (39.37) inches. 



