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parA 



ants are usually fed by juices secreted by the worker 

 nurses. 



Ants, it is scarcely necessary to observe, consist, in 

 each species, of three sets of individuals, or, as some 

 express it, of three sexes — namely, males, females, and 

 workers ; the last-mentioned being undeveloped females. 

 The perfect sexes are winged on their first attaining the 

 adult state ; they alone propagate their kind, flying away, 

 previous to the act of reproduction, from the nest in which 

 they have been reared. This winged state of the perfect 

 males and females, and the habit of flying abroad before 

 pairing, are very important points in the economy of 

 ants ; for they are thus enabled to intercross with mem- 

 bers of distant colonies which swarm at the same time, 

 and thereby increase the vigour of the race, a proceeding 

 essential to the prosperity of any species. In many ants, 

 especially those of tropical climates, the workers, again, 

 are of two classes, whose structure and functions are 

 widely different. In some species they are wonderfully 

 unhke each other, and constitute two well-defined forms 

 of workers. In others, there is a gradation of individuals 

 between the two extremes. The curious differences in 

 structure and habits between these two classes form an 

 interesting, but very difficult, study. It is one of the 

 great peculiarities of the Saiiba ant to possess three classes 

 of workers. My investigations regarding them were far 

 from complete ; I will relate, however, what I have 

 observed on the subject. 



When engaged in leaf-cutting, plundering farinha, and 

 other operations, two classes of workers are always seen. 

 They are not, it is true, very sharply defined in structure, 

 for individuals of intermediate grades occur. All the 

 work, however, is done by the individuals which have 

 small heads, whilst those which have enormously large 

 heads, the worker-majors, are observed to be simply 

 walking about. I could never satisfy myself as to the 

 function of these worker-majors. They are not the 

 soldiers or defenders of the working portion of the com- 

 munity, like the armed class in the Termites, or white 

 ants ; for they never fight. The species has no sting, 

 and does not display active resistance when interfered 

 with. I once imagined they exercised a sort of super- 

 intendence over the others ; but this function is entirely 

 unnecessary in a community where all work with a pre- 



