Liquids poured upon the surface cannot, owing to the crumby nature of the humus, exert any appreciable hydraulic pressure. This is a fact of huge importance in the practical management of organic refuse. All effete organic matter instantly becomes the prey of animals and plants. The dead body of an animal teems with life—_Le roi est mort, vive le roi_. M. Mégnin, a skilled entomologist and a member of the French Academy of Medicine, has made a study, which is full of gruesome interest, of the living machinery which makes away with the bodies of animals not buried but exposed to the air and protected from beasts of prey. M. Mégnin shows that the destruction of the animal is accomplished in no haphazard fashion, but that successive squadrons of insects are attracted by the successive stages of putrefaction. The first squadron which arrives, sometimes before death and always before putrefaction, consists entirely of dipterous insects, house-flies and their relative, the blow-fly. The next squadron are also diptera, and are said to be attracted by the commencing odour of decomposition. These squadrons use the carcase as a procreant cradle, and thus ensure the nourishment of the larvæ so soon as they are hatched. Amongst these flesh-seeking flies there are said to be specialists which prefer the flesh of particular animals. The third squadron is attracted when the fat begins to undergo an acid fermentation. These consist of coleoptera and lepidoptera, beetles and butterflies, and among them is _Dermestes Lardarius_, the Bacon Beetle. When the fats become cheesy the diptera reappear, and among them is _Pyophila Casei_, the fly which breeds jumpers in cheese, which is accompanied by a beetle, whose larvæ are connoisseurs in rancidity. When the carcase becomes ammoniacal, black, and slimy, it is visited by a fifth squadron of flies and beetles. And these are succeeded by the sixth squadron, consisting of acari or mites, whose function it is to dry up the moisture and reduce the carcase to a mummy-like condition. The dried carcase proves attractive to the seventh squadron, consisting of beetles and moths, some of which are the familiar pests of the housewife, the furrier, and the keepers of museums. These animals gnaw the softer parts, such as ligaments, and leave nothing but a fine powder behind them, which is in fact their dung. The last and eighth squadron consists solely of beetles, which clean up the débris, in the shape of dung, shells, pupa cases, &c., of the seven squadrons which have preceded them. M. Mégnin, being an entomologist and not a bacteriologist, deals exclusively with the insects concerned in making away with a carcase, but it is evident that bacteria work hand in hand with them.