Notices of New Books. 8543 



them up. This, repeated many times, at last seemed to intimidate 

 them, for we were free from their visits during the remainder of my 

 residence at the place. What they did with the hard dry grains of 

 mandioca I never was able to ascertain, and cannot even conjecture. 

 The meal contains no gluten, and would therefore be useless as cement. 

 It contains only a small relative portion of starch, and, when mixed 

 with water, it separates and falls away like so much earthy matter. It 

 may serve as food for the subterranean workers, but the young or larvae 

 of 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 unde- 

 veloped 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 members 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 unlike 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 opera- 

 tions, 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, while those which have enormously large heads (the 

 worker-majors), are observed to be simply walking about. I could 

 never satisfy myself as to the functions 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 



