The sociable humour of these horses makes them compassionate towards their fellows who are enslaved by man, and if a harnessed cart meets on its road a free band, it is a serious matter to the owner. They run up and surround the enslaved horse, saluting him with their cries and gambols, having the air of inviting him to throw his harness to the winds and follow them on the plain, where grass grows for all without work. Naturally the driver endeavours to preserve his noble conquest, and distributes blows with the whip to those who wish to debauch it. Then the wild horses become furious, and throw themselves on the vehicle; they break it with their feet and cut their comrade's traces with their teeth to enable him to share their own free life. The enterprise satisfactorily concluded, they gallop away neighing in triumph. It is owing to their union in large bands that Crows have so little to fear from diurnal birds of prey; if one approaches, they do not hesitate to throw themselves on him altogether. The Great Horn Owl, however, causes many ravages among them; for when asleep at night the Crow is without defence against the ravisher, for whom, on the contrary, obscurity is propitious. Thus they recognise him as a hereditary enemy, and never allow an opportunity of revenge to pass without profiting by it. If by chance an owl appears by day and one of them perceives him, immediately a clamour arises--a veritable cry of war; all those who are in the neighbourhood fly to the spot, and business ceases; the nocturnal bird of prey is assaulted, riddled with blows from beaks, stunned, his feathers torn out, and, notwithstanding his defence, he succumbs to numbers. In all the preceding examples the social species unite for the common security the forces and effects which they can derive from their own organs. I have spoken of the Apes and described how they defend themselves with their hands and teeth; but in certain cases they use weapons, employing foreign objects like a club or like projectiles. Acts of this nature are considered to indicate a high degree of development, and it has often been repeated that they are the appanage of man alone; we have, however, seen the _Toxotes_, who, like all fishes, is not particularly intelligent, squirt water on to his victims. It is not easy to understand how a greater intellectual effort is required to throw a stone with the hand than to project water with the mouth. This is what the apes do, throwing on their assailants from the heights of trees everything which comes to hand: cocoa-nuts, hard fruits, fragments of wood, etc.