This observation naturally leads to two others by two different observers. Thus, Moggridge says: "I was able to watch the operation of removing roots which had pierced through their galleries, belonging to seedling plants growing on the surface, and which was performed by two ants, one pulling at the free end of the root, and the other gnawing at its fibers where the strain was greatest, until at length it gave way." Again, as previously quoted in another connection, he says that two ants sometimes combine their efforts, one stationing itself near the base of a footstalk and gnawing at the point of greatest tension, while the other hauls upon and twists it.
The other observer to whom I have referred is McCook, who says of the harvesting ants of America that he has seen "the workers, in several cases, leave the point at which they had begun a cutting, ascend the blade, and pass as far toward the point as possible. The blade was thus borne downward, and, as the ant swayed up and down, it really seemed that she was taking advantage of the leverage thus gained, and was bringing the augmented force to bear upon the fracture. In two or three cases there appeared to be a division of labor; that is to say, while the cutter at the roots kept on with his work, another ant climbed the grass-blade and applied the power at the opposite end of the lever. This position may have been quite accidental, but it certainly had the appearance of voluntary coöperation."
These observations serve to render less improbable the following quotation taken from Bingley's account of Captain Cook's expedition in New South Wales, and vouched for by Sir J. Banks. Green ants were seen forming their nests in trees by "bending down several of the leaves, each of which is as broad as a man's hand, and gluing the points of them together so as to form a purse. . . . We saw thousands uniting all their strength to hold them in this position, while other busy multitudes within were employed in applying the gluten that was to prevent their returning back."
Moggridge says that he has seen the harvesting ants of Europe clustering round the larva of a certain beetle, and directing it toward some small opening in the soil, "which it would quickly enlarge and disappear down"; and he believes that "these attentions were purely selfish," the ants availing "themselves of the tunnel thus made down into the soil."
McCook says of the harvesters of America that they dislike shade, so that if a tree grows up in their vicinity and casts a shadow over their nest they forthwith migrate. He gives in this connection a statement which I regard as bordering on the incredible, and therefore I desire it to be specially observed that it is not very evident from
