HARDWICKE'S SCIENCE-GOSSIP. 



[Jax. 1, 1SGS. 



species select their homes in the open sunshine, and 

 construct pavements. Their pavements are always 

 circular, and constructed pretty much on the same 

 plau. During the ten years' drought that prevailed 

 here, and which seemed very favourable to the 

 increase of this species of ant, they suffered their 

 pavements to remain flat, sometimes even basin- 

 form. But the drought could not continue always. 

 The rain, which would be certain to drown the ants 

 should it come upon their flat and basin-form 

 pavements, would return again some day, and they 

 seemed to know when this much-dreaded event 

 would occur. At least six months previous to the 

 coming of the rain, they commenced, universally, 

 building up mounds in the centre of the pavements. 

 To these mounds in the prairie they brought the 

 little pellets of earth thrown to the surface by the 

 earth-worms, and piled them up into a circular 

 mound a foot or more in height. In sandy soil it is 

 constructed of coarse sand, and in rocky situations 

 they build it of gravel, and the pieces are so large, 

 and the mound so high (18 inches to 2 feet, with a 

 4 feet base) that the beholder is overwhelmed with 

 wonder. I know of one of these stone pyramids 

 nearly 3 feet high, and 5.' to G feet base, in which 

 there are many little fragments of stone, some of 

 them carried to the very top, any one of which 

 would weigh more than 25 ants. Internally, the 

 ant mound contains many neatly constructed cells, 

 the floors of which are horizontal ; and into these 

 cells the eggs, young ones, and their stores of grain 

 are carried in time of rainy seasons. 



The mound itself, and the surface of the ground 

 around it, to the distance of 4 or 5 feet, sometimes 

 more, from the centre, is kept very clean, like a 

 pavement. Everything that happens to be dropped 

 upon the pavement is cut to pieces and carried 

 away. The largest dropping from the cows will, in 

 a short time, be removed. I have placed a large 

 corn-stalk on the pavement, and in the course of 

 two or three days found it hollowed out to a mere 

 shell ; that too, in a short time, would be cut to 

 pieces and carried off. Not a green thing is suf- 

 fered to grow on the pavement, with the exception 

 of a single specimen of grain-bearing grass (Aristida 

 stricta). This the ant nurses and cultivates 

 with great care ; having it in a circle around, and 

 2 or 3 feet from the centre of the mound. It also 

 clears away the weeds and other grasses all around 

 outside of the circular row of Aristida, to the 

 distance of 1 or 2 feet. The cultivated grass 

 flourishes luxuriantly, producing a heavy crop of 

 small, white, flinty grams, which under the micro- 

 scope have the appearance of the rice of commerce. 

 When it is ripe it is harvested by the workers, and 

 carried, chaff and all, into the granary cells, where 

 it is divested of the chaff, which is immediately 

 taken out and thrown beyond the limits of the pave- 

 ment, always to the lee side. The clean grain is 



carefully stored away in dry cells. These cells are 

 so constructed that water cannot reach them, 

 except in long wet spells, when the earth becomes 

 thoroughly saturated, and dissolves the cement with 

 which the granary cells are made tight. This is a 

 great calamity, and if rain continues a few days it 

 will drown out the entire community. In cases, 

 however, where it has continued long enough only 

 to wet and swell their grain, as soon as a sunny day 

 occurs, they take it all out, and spreading it in a 

 clean place, after it has sunned a day or two, or is 

 fully dry, they take it in again, except the grains 

 that are sprouted ; these they invariably leave out. 

 I have seen at least a quart cf sprouted seeds left 

 out at one place. 



They also collect the grain from several other 

 species of grass, as well as seed from many kinds of 

 herbaceous plants. They like almost any kind of 

 seeds— red pepper seeds seem to be a favourite 

 with them. 



In a barren rocky place in a wheat-field, "a few 

 days after harvest, I saw quite a number of wheat 

 grains scattered over the pavement of an ant city, 

 and the labourers were still bringing it out. I 

 found the wheat quite sound, but a little swelled. 

 In the evening of the same day I passed there 

 again ; the wheat had dried, and they were busily 

 engaged carrying it in again. 



The species of grass they so carefully cultivate is 

 a biennial. They sow it in time for the autumnal 

 rains to bring it up. Accordingly, about the 1st of 

 November, if the fall has been seasonable, a beau- 

 tiful green row of the ant rice, about 4 inches wide, 

 is seen springing up on the pavement, in a circle of 

 14 to 15 feet in circumference. In the vicinity of 

 this circular row of grass they do not permit a 

 single spire of any other grass or weed to remain a 

 day ; leaving the Aristida untouched until it is ripe, 

 which occurs in June of the next year, they gather 

 the seeds and carry them into the granaries as 

 before stated. There can be no doubt of the fact 

 that this peculiar species of grass is intentionally 

 planted, and, in fanner-like manner, carefully- 

 divested of all other grasses and weeds during the 

 time of its growth, and that after it has matured 

 and the grain stored away, they cut away the dry 

 stubble and remove it from the pavement, leaving it 

 unencumbered until the ensuing autumn, when the 

 same species of grass, and in the same circle, appears 

 again, receiving the same agricultural care as did 

 the previous crop ; and so on, year after year, as I 

 know to be the case on farms where their habitations 

 are, during the summer season, protected from the 

 depredations of cattle. Outside of the fields they 

 sow the grass seeds, but the cows crop it down two 

 or three times, when, finding that there is no chance 

 to carry on their agricultural pursuits, they cut it 

 all away and re-establish the clean pavement. Our 

 cattle did not often crop the ant rice until their 



