THE NATURALIST ON THE RIVER AMAZONS. 



shown satisfactorily lo what use it applies 

 tiie leaves. I discovered this only after much 

 lime spent in investigation. The leaves are 

 used to thatch the domes which cover the 

 entrances to their subterranean dwellings, 

 thereby protecting from the deluging rains 

 the. young broods in the nests beneath. The 

 larger mounds, already described, are so ex-, 

 tensive that few persons would attempt to re- 

 move them for the purpose of examining 

 their interior ; but smaller hillocks, covering 

 other entrances to the same systeuffcf tunnels 

 and chambers, may be found in sheltered 

 places, and these are always thatched with 

 leaves, mingled with granules of earth. The 

 heavily-laden workers, each carrying its seg- 

 ment of leaf vertically, the lower edge se- 

 cured in its mandibles, troop up and cast 

 their burdens on the hillock ; another relay 

 of laborers place the leaves in position, cov- 

 ering them with a layer of earthy granules, 

 which are brought one by one from the soil 

 beneath. 



The underground abodes of this wonderful 

 ant are known to be very extensive. The 

 Rev. Hamlet Clark has related that the Saiiba, 

 of Rio de Janeiro, a species closely allied to 

 ours, has excavated a tunnel under the bed 

 of the river Parahyba, at a place where it is 

 as broad as the Thames at London Bridge. At 

 the Magoary rice-mills, near Paia, these ants 

 once pierced the embankment of a largo 

 reservoir : the great body of water which it 

 contained escaped before the damage could 

 be repaired. In the Botanic Gardens, at 

 Para, an enterprising French gardener tried 

 all he could think of to extirpate the Saiiba. 

 With this object he made tires over some of 

 the main entrances to their colonies, and 

 blew the fumes of sulphur down the galleries 

 by means of bellows. I saw the smoke issue 

 from a great number of outlets, one of which 

 was seventy yards distant from the place 

 where the bellows were used. This shows 

 how extensively the underground galleries 

 are ramified. 



Besides injuring and destroying young 

 trees by despoiling them of their foliage, the 

 8aiiba ant is troublesome to the inhabitants 

 from its habit of plundering the stores of pro- 

 visions in houses at night, for it is even more 

 active by night (ban in the day-time. At first 

 I was inclined to discredit the stories of their 

 entering habitations and carrying off grain 

 by grain the farinha or mandioca meal, the 

 bread of (he poorer classes of Brazil. At 

 length, while residing at an Indian village on 

 the Tapajos, I had ample proof of the fact. 

 One night my servant woke me three or four 

 hours before sunrise by calling out that the 

 rats were robbing the farinha baskets ; the 

 article at that time being scarce and dear. I 

 got up, listened, and found the noise was 

 very unlike that made by rats. So I took the 

 light and went into the storeroom, which 

 was close to my sleeping-place. I there 

 found a broad column of Saiiba ants, consist- 

 ing of thousands of individuals, as busy jis 

 possible, passiui!; to aad fro ben*ceu the doo* 



and my precious baskets. Mast of tho^e* 

 passing outward were laden each with , grain:; 

 of farinha, which was, in some cases, larger 

 and many limes heavier than the bodies~of 

 the carriers. Farinha consists of grains of 

 similar size and appearance to the tapioca of! 

 our shops ; both are products of the same 

 root, tapioca being the pure starch, and 

 farinha the starch mixed with woody fibre, 

 the latter ingredient giving it a yellowish 

 color. It was amusing to see some of tha 

 dwarfs, the smallest members of their family, 

 staggering along, completely hidden under 

 their load. The baskets, which were on a 

 high table, were entirely covered with anls, 

 many hundreds of whom were employed ia 

 snipping the dry leaves which served as lin- 

 ing. 1 iiis produce the rustling sound which 

 had at first disturbed us. My servant told, 

 me that they would carry off the whole con- 

 tents of the two baskets (about two bushels) 

 in the c./urse of the night, if they were not 

 driven oft' ; so we tried to exterminate them, 

 by killing them with our wooden clogs. It 

 was impossible, however, to prevent fresh 

 hosts coming in as fast as we killed their 

 companions. They returned the next night ; 

 and I was then obliged to lay trains of gun- 

 powder along their line, and blow them up. 

 This, repeated many times, at last seemed ta 

 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 was never able to 

 ascertain, and cannot even conjecture. The 

 meal contains no gluten, and therefore would 

 be useless as cement. It contains only a 

 small relative portion of starch, and, when 

 mixeo 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 \anad 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 indi- 

 viduals, or, as some express it, of three sexes 

 uamety, mules, females, and workers ; the 

 last-mentioned being undeveloped females. 

 The pei feet sexes are winged on their first 

 attaining the adult state ; they alone propa- 

 gate their kind, flying away, previous to the 

 act of reproduction, from the nest in which 

 they have been reared. This winged slate 

 of the perfect ma'es and females, and the 

 habit of flying abroad before pairing, are very 

 important paints 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 vigor 

 of the race, a proceeding essential to the pros- 

 perity of any species. In many ants, espe- 

 cially 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-di fined forms . 

 of workers. In ethers, there is a gradation 

 . f individuals between the two extremes. 

 The curious differences in structure and. 



