There are, however, other animals which enjoy a relative although not absolute immunity to snake poison, and amongst these may be mentioned swine, hedgehogs, and the mongoose. Swine, it is well known, will greedily devour reptiles, and in some countries they are specially trained up and employed for this purpose. Of particular interest, however, are some experiments which were carried out to test the traditional immunity towards this toxin ascribed to the mongoose. These animals are very useful in sugar plantations, and are largely employed to keep down the serpents and rats with which they abound, for the carnivorous little mongoose is extremely partial to such prey. Attempts have been made by sugar planters to introduce them into Martinique, where they are not found in the wild state, as in the island of Guadeloupe. Six specimens of the mongoose were forwarded to Calmette from Martinique, and these particular animals, it was stated, had never been set at liberty since they were imported, so that they had had no previous experience of snakes or venom. On arriving at the laboratory, one of these little creatures was placed in a glass cage along with a large cobra. The cobra, at once rising up and dilating its neck, darted with fury upon the mongoose; but the latter, thanks to its extraordinary agility, escaped being caught, and took refuge, stupefied and terrified for the moment, in a corner of the cage. This stunned condition, however, did not last long, for just as the incensed cobra was preparing to make a fresh attack upon its insignificant little victim, the latter, with wide-open mouth, rushed and jumped upon the head of its enemy, viciously bit through its upper jaw, and broke its skull in a few seconds. Thus, although in size but a little larger than a squirrel, this tiny creature was more than a match for a cobra two yards long. Artificial inoculations of cobra venom into the mongoose fully substantiated all the observed facts as to its remarkable immunity from this poison. A dose sufficient to kill a large rabbit in three hours was absolutely without effect; only when the venom was introduced in quantities amounting to as much as eight milligrammes was it followed by fatal results. Thanks, therefore, to their extraordinary agility and remarkable power of resisting the effects of this lethal toxin, these little animals are able to battle successfully with the most dangerous reptiles. The rapidity with which serpent venom becomes absorbed by the system is almost incredible, and is well illustrated by the following experiment. A rat was inoculated with venom near the tip of its tail. _One minute later_ the latter was cut off a short distance above the point of inoculation; but this operation was quite unable to save the animal's life, for even in that brief interval the poison had accomplished its fatal work, and a few hours later claimed its victim.