We find a great variety in the mode of life of these hirudinidæ; and if we sometimes meet with some which are sober and delicate, the greater part show a voracity of which it is difficult to form any idea. A leech has been met with in Senegal which draws a quantity of blood equal to the weight of its body. There are leeches which devour entire earth-worms. Fortunately the greater species are not the most voracious: we might feel rather uneasy in the midst of leeches similar to that which Blainville has described under the name of _Pontobdella lævis_, which is not less than a foot and a half in length. It is generally thought that all leeches are aquatic, but this is a mistake. In the warm regions of the Old and New World, there live in the midst of the brushwood, leeches which attack the traveller as well as his horse, and suck the blood of both without their perceiving it. Hoffmeister gives the following account with reference to small leeches in the island of Ceylon:-- He had amused himself one evening by collecting some phosphorescent insects which were hovering around him in considerable numbers; on entering afterwards a lighted room, he perceived streaks of blood all down his legs. This was the effect of the bites of leeches. These creatures, said he, made a painful impression on me, the remembrance of which was terrible. This same leech, which bears the name of _Hirudo tagalla_, or _Ceylonica_, lives in the thickets and woods of the Philippine Islands. There also it attacks horses as well as men. It has also been noticed on the chain of the Himalayas, 11,000 feet 112 above the level of the sea. Japan and Chili also have terrestrial leeches. The _Cylicobdella lumbricoides_ is a blind leech, which has been found by F. Müller in damp earth, in Brazil. The aquatic leeches are better known, and with but few exceptions, the accidents produced by them are little to be feared. In Algeria it is not uncommon, as army surgeons tell us, to see soldiers, while drinking spring water, swallow small leeches which may do them injury. We find from official reports that the French soldiers often suffered, during the campaigns in Egypt and Algeria, from an aquatic leech (_Hoemopis vorax_), which attacked the mouth and the nostrils, and did not respect man any more than horses, camels, and oxen. The leech discovered by Dr. Guyon under the eyelids and in the nasal fossæ of the crab-eating heron of Martinique, is probably a monostomum, and not one of the hirudinidæ. Leeches have also been found on turtles under the name of _Eubranchella Branchiata_. Say saw one on a chelonian, and others on tritons and frogs.