In this way, at my laboratory, I have been able to preserve, in perfect condition for more than two years, Indian _Cobras_ and _Fers-de-lance_ from Martinique, taking care to keep them in a hothouse, at a temperature of about 82° to 86° F. It is also very important to place inside the cases a vessel full of water, which should be frequently changed, for almost all snakes drink often and like to bathe for whole days at a time. [Illustration: FIG. 18.--CATCHING A _Cobra-di-Capello_ (_Naja tripudians_), SECOND STAGE. (At the French Settlement of Pondicherry, in India.)] Within their reach should be placed in addition branches and rockwork, against which they rub at the _moulting_ times, in order periodically to rid themselves of their scarf-skin. While moulting, snakes must neither be touched nor fed, since to force them to take food at such a time would be fatal. _Snake-catching._--The capture of poisonous snakes, in order to keep them alive, can only be performed without danger by skilful persons, who are possessed of much coolness. The best way of securing them is suddenly to pin the neck to the ground by means of a stick held horizontally, or a small two-pronged fork of wood or metal (fig. 17). The stick is rolled along until close to the occiput (fig. 18). The animal can then be seized with the hand immediately behind the head, in such a way that it is impossible for it to turn and bite. It is then put into a wire cage, provided with a small movable trapdoor, with the fastening on the outside. In this way poisonous snakes can be sent to a distance, and left without food for one or even two months, provided that they be kept in a place which is somewhat moist and sufficiently warm. Fig. 19 shows how captured cobras are carried in India, in the environs of Pondicherry. They are enclosed in earthern _chatties_, or in baskets of plaited bamboo, which are provided with covers, and are very convenient for carrying snakes short distances. [Illustration: FIG. 19.--HINDU CARRYING TWO CAPTURED COBRAS IN “CHATTIES.”] CHAPTER III. _DESCRIPTION OF THE PRINCIPAL SPECIES OF POISONOUS SNAKES. THEIR GEOGRAPHICAL DISTRIBUTION._ Poisonous snakes are especially common in the tropical zones of the Old and New Worlds. The species found in Europe are but of small size and not very formidable. In hot countries, on the other hand, they attain large dimensions, their venom is much more active, and, although they hardly ever attack man, and in most cases avoid him, they cause a considerable number of fatal accidents. It is sometimes a rather difficult matter to recognise from the mere appearance of a snake whether it is poisonous or not. Naturalists themselves are occasionally deceived. It is therefore useful to learn to distinguish the most dangerous species by their external characters, and to know in what countries there is a risk of their being encountered. _A.--EUROPE._