The next mental faculty is _reason_, which stands at the summit; but still there are few persons who will deny that animals possess some power of reasoning. A few illustrations will be all that is necessary to satisfy the inquiring mind on this point. Reugger, a most careful observer, states that when he first gave eggs to his monkey in Paraguay they smashed them, and thus lost much of their contents; afterward they gently hit one end against some hard body, and picked off the bits of shell with their fingers. After cutting themselves _once_ with any sharp tool, they would not touch it again, or would handle it with the greatest caution. Lumps of sugar were often given them, wrapped up in paper; and Reugger sometimes put a live wasp in the paper, so that in hastily unfolding it they got stung; after this had _once_ happened, they afterward first held the packet to their ears to detect any movement within. The following cases relating to dogs are described by Darwin: Mr. Colquhoun winged two wild ducks, which fell on the farther side of a stream; his retriever tried to bring over both at once, but could not succeed; she then, though never before known to ruffle a feather, deliberately killed one, brought over the other, and returned for the dead bird. Colonel Hutchinson relates that two partridges were shot at once--one being killed, the other wounded; the latter ran away, and was caught by the retriever, who, on her return, came across the dead bird; "she stopped, evidently greatly puzzled, and after one or two trials, finding she could not take it up without permitting the escape of the winged bird, she considered a moment, then deliberately murdered it by giving it a severe crunch, and afterward brought away both together. This was the only known instance of her ever having wilfully injured any game. Here we have reason, though not quite perfect; for the retriever might have brought the wounded bird first, and then returned for the dead one, as in the case of the two wild ducks. I give the above cases as resting on the evidence of two independent witnesses; and because in both instances the retrievers, after deliberation, broke through a habit which was inherited by them (that of not killing the game retrieved), and because they show how strong their reasoning faculty must have been to overcome a fixed habit."[55] It has often been said that no animal uses any tool, but this can be so easily refuted on reflection, that it is hardly worth while considering; for illustration, though, the chimpanzee in a state of nature cracks nuts with a stone; Darwin saw a young orang put a stick in a crevice, slip his hand to the other end, and use it in a proper manner as a lever. The baboons in Abyssinia descend in troops from the mountains to plunder fields, and when they meet troops of another species a fight ensues. They commence by rolling great stones at their enemies, as they often do when attacked with fire-arms.