1896.] on the Circulation of Organic Matter, 163 



It is the samo with organic liquids. If these be poured on the 

 surface, the " living earth " (i. e. the humus stuffed with animal and 

 microbial life) purges them of their organic matter, and transmits a 

 relatively pure liquid to the deeper layers. If they be taken to the 

 barren subsoil direct, as in underground sewers and cesspools, they 

 escape the purifying action of air and aerobic organisms, and inevitably 

 poison the water. Filthy liquids accumulating in cesspools and 

 leaking under pressure to our wells have cost us health and money 

 incalculable. 



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. Megnin, 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. Megnin shows that the destruction of the animal is accom- 

 plished 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 larvae 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 lepidopter.% 

 beetles and butterflies, and among them is Dermestes Lardarius, the 

 Bacon Beetle. 



^hen the fats become cheesy, the diptera reappear, and among 

 them is Pyopliila Casei, the fly which breeds jumpers in cheese, who is 

 accompanied by a beetle the larvae of which are connoisseurs of 

 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, con- 

 sisting of beetles and moths, some of which are the familiar pests of 



M 2 



