"They must be secretary birds," he whispered; "known as the _Serpentarius cristatus_. They are determined enemies of serpents, and will attack the most venomous without fear. The secretary bird is so called on account of that crest at the back of his head, which looks something like a pen stuck behind the ear. One might suppose, on account of his long legs, that he should be classed among the cranes and storks, but his curved beak and internal organisation show that he belongs to the falcon tribe. His feet are incapable of grasping, and thus he runs along as we see over the sandy ground with a speed which enables him to overtake the most active reptiles." Presently we saw the birds dart off, and in another instant a large snake rose up before them. One stood still, while the other gave battle to the reptile. The serpent made every attempt to get back to its home, but the bird each time sprang before it with an active leap, and cut off its retreat. Whenever the serpent turned, the bird again placed itself in its front. At length the reptile, as if determined to try what courage would do, raised up its head, which swelled with rage, and displayed its menacing throat and inflamed eyes, hissing fiercely. No human being would have wished at that moment to have encountered it. For an instant the bird stopped, but it was not for want of courage; and spreading out its wings, it covered itself with one of them, while with the other, which was armed with horny protuberances like little clubs, it struck the serpent a blow which knocked it over. Again and again the serpent rose to receive the same treatment, till at length it lay quiet on the grass. The bird instantly flew upon it, and with one stroke of its powerful bill laid open its skull, and then immediately pressing it to the ground with its feet, held it fast. We were unable to see whether it swallowed the head or not, for its companion catching sight of us, they ran off with their prey to devour it at their leisure.