represents the early stage of an insect which, in its full growth, still lives upon grass, and is easily recognised by its triangular shape and its ability of jumping like a grasshopper.” “If the insect is cleared from the mass of froth it will crawl quite rapidly along the stem of the plant, stopping, at times, to pierce the stem for the purpose of sucking the juices within, and finally settling down in earnest, clutching the stem with its legs. After sucking for some time, a clear fluid is seen to exude from the end of the abdomen, flowing over the body first, and gradually filling up the spaces between the legs and the lower part of the body and the stem upon which it rests. During all this time not a trace of an air-bubble appears; simply a clear, slightly viscid fluid is exuded, and this is the only matter that escapes from the insect. This state of partial immersion continues for an hour or more. During this time, and even when walking, the posterior segments of the insect’s abdomen are extended at intervals, the abdomen turning upwards at the same time. It is a kind of reaching-up movement, but whether this action accompanies a discharge of fluid, or is an attempt at reaching for air, I have not ascertained. Suddenly the insect begins to make bubbles by turning its tail out of the fluid, opening the posterior segment, and grasping, as with a pair of claspers, a moiety of air, then turning the tail down into the fluid, again, and instantly allowing the enclosed air to escape. These movements go on at the rate of seventy or eighty times a minute. The tail is moved alternately to the right and left in perfect rhythm, so that the bubbles are distributed on both sides of the body, and these are crowded towards the head, till the entire fluid is filled with bubbles, and the froth thus made runs over the back and around the stem. In half a minute some thirty or forty bubbles are made in this way—a bulk of air two or three times exceeding that of the body—without the slightest diminution in the size of the body.”