CHAP. X. EMIGRATION OP ANT3. 33$ 



tending them with the same sort of assiduity as M. Huber 

 relates in the foregoing account. These may truly be 

 called the cattle of the Brazilian ants i for not only do 

 they furnish them with milk, but most of the species 

 in imitation of the ox, and other ruminating quad- 

 rupeds of that class possess horns growing out of 

 their heads (Membracis ensata, &), or are otherwise 

 armed (Bocydium clavatum, a) : while their large abrupt 

 heads remind the entomologist of the physiology of the* 

 bull or cow. Our remarks did not extend to the par- 

 ticular mode by which these insects eject their secre- 

 tion ; but the surrounding leaves of the stalk they in- 

 habit are very clammy, like those of plants infested with 

 the Aphides of Europe : and the circumstance of their 

 always being attended by ants, places the fact beyond 

 all doubt. 



(341.) The emigrations undertaken by ants, when 

 provisions become scarce, or the population of their 

 nests excessive, open a new field for our astonishment 

 and admiration. Sometimes these desertions 4 of their 

 former dwellings are prompted by other and less worthy 

 motives, for they will be expelled by a neighbouring 

 enemy of their own family, or like the ambitious 

 rulers of the earth will themselves become the in- 

 vaders, that they may possess themselves of the nest of 

 another race, situated more pleasantly than their own. 

 The indefatigable Huber has placed these facts beyond 

 doubt ; and as his is the chief authority, we cannot do 

 better than present the reader with the substance of his 

 observations, chiefly made upon the Formica rufa, 

 already mentioned.* The first step which is taken on 

 these occasions, is to discover and decide upon the site 

 of the new habitation : this task is assigned to the 

 labourers, who do it, as M. Huber thinks, without 

 consulting the rest of the society. Having fixed upon 

 an eligible spot, their next business is to make it known 

 to the rest ; and they adopt a mode which has been 

 well compared to that of raising recruits for the ser- 



* Int. to Ent. vol. ii. p. 62. 



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