Trusting to his agility and the certainty of his eye, the Indian ichneumon or Mongoos attacks without hesitation the most venomous serpents. The cobra, which drives even the leopard to flight, rises before the little creature with swelling hood and fury in its eye; but, swift as thought, the ichneumon, avoiding the death-stroke of the projecting fangs, leaps upon its back, and fastening his sharp teeth in the head, soon despatches the helpless reptile. The serpents sometimes even feed upon their own brethren. Thus a rat-snake in the Zoological Gardens was once seen to devour a common Coluber Natrix, but not having taken the measure of his victim, he could not dispose of the last four inches of his tail, which stuck out rather jauntily from the side of his mouth, with very much the look of a cigar. After a quarter of an hour the tail began to exhibit a retrograde motion, and the swallowed snake was disgorged, nothing the worse for his living sepulchre, with the exception of the wound made by his partner when first he seized him. A python in the same collection, who had lived for years on friendly terms with a brother nearly as large as himself, was found one morning sole tenant of his den. As the cage was secure, the keeper was puzzled to know how the serpent had escaped. At last it was observed that the remaining inmate had swollen remarkably during the night, when the truth came out. [Illustration: MONGOOS.] When we consider that the snakes have neither legs, wings, nor fins, and are indeed deprived of all the usual means of locomotion, the rapidity of their progress is not a little surprising. On examining the anatomical structure of their body, however, it will be remarked that while we have only twelve pairs of ribs united in front by the breast-bone and cartilage, the snake has often more than three hundred, unconnected in front, and consequently much more free in their motions, a faculty which is still further increased by the great mobility of the spondyli of the backbone. Between the ribs and the broad transverse scales or plates which exist on the belly of all such serpents as move rapidly, we find numerous muscles connecting them one with another, and thus, amply provided with a whole system of strong pulleys and points of attachment, the reptile, bringing up the tail towards the head, by bending the body into one or more curves, and then again resting upon the tail and extending the body, glides swiftly along, not only upon even ground, but even sometimes from branch to branch, as the smallest hold suffices for its stretching out its body at a foot’s length into the air, and thus reaching another sallying point for further progress.