shoots round the orchid-lover’s neck and beneath his shirt front. When they are pulled away a few drops of blood flow from the skin where the absorbent shoots had applied themselves. The victim recovers. When we take a survey of the “stings” and poison-fangs and spurs of animals, we find a much greater abundance and variety of these weapons than in plants. They serve animals not only as a means of defence, but very often for the purpose of attacking and paralysing their prey. We have to distinguish broadly between (_a_) gut-poisons and (_b_) wound-poisons. The slimy surface of the skin and the juices of animals are often poisonous if introduced into wounds, but harmless if swallowed, though in the toad and salamander the skin contains a poison which acts on the mouth and stomach. Thus the blood of the eel is poisonous to higher animals if injected beneath the skin, though not poisonous when swallowed. Pasteur found that the saliva of a healthy human baby a few weeks old produced convulsions when injected beneath the skin of a rabbit. The fluid of the mouth in fishes (_Muræna_), in some lizards (_Heloderma_), and some warm-blooded quadrupeds, like the skunk, is often poisonous, and is introduced into the wound inflicted by a bite. The elaboration of a sac of the mouth-surface secreting a special quantity of poison to be injected by aid of a grooved tooth, such as we find in poisonous snakes, is only a mechanical improvement of this more general condition. The same general poisonous quality is found in the slime of the skins of fishes which have spines by means of which poisonous wounds are inflicted (sting-rays). And here, too, an elaboration is effected in some fishes in which a sac is provided for the accumulation of the poison, and a specially grooved spine, to convey the poison into the wound inflicted by it. A common fish on our coasts, the weever (probably the same word as viper), is provided with grooved, stinging spines, but no special poison-sac. Some of the poison-carrying spines support the front portion of the dorsal fin, which is of a deep black colour, a striking instance of the warning coloration which poisonous animals often possess.