1876.] Nature’s Scavengers. 167 
and its congeners, the Longicornes, termed wood-beetles by 
pre-eminence, and many others : in warmer climates the 
task is taken up by the splendid Buprestidse, the Dynastidas 
(such as the elephant and Hercules beetles), and some spe- 
cies of the dung-burying tribes, as well as by the numerous 
and gigantic Longicornes of those regions, such as the 
“ harlequin.” The Termites , or white ants as they are im- 
properly called, also engage in the task of removing decayed 
wood, but as they are equally prone to consume sound timber 
they must be regarded as scavengers of the lowest or objec- 
tionable type, like the carrion-flies. 
Fallen leaves are not efficiently consumed by any class of 
animals, and where they have accumulated in quantities 
they may still be found in the next season in various stages 
of decomposition. Slugs and snails are considered as the 
scavengers for effete vegetable matter, but they occupy them- 
selves chiefly with eating sound leaves and fruits, and hence 
they must rank in the lowest class. To some extent decayed 
leaves are pulled into the ground by earth-worms, and when 
far advanced in decomposition are attacked by the Brache- 
lytra, and others of the many insects that help to dispose of 
the dung of herbivorous animals. But there is evidently no 
systematic removal at all commensurate with the occasion. 
That the waters are polluted by their inmates, animal and 
vegetable, needs little formal proof. Their excrements, their 
cast-off skins, their decaying bodies, their abortive ova, all 
contribute a large supply of offensive and injurious matter. 
Nor are the dwellers on land excluded. From the autumn 
leaves which fall into the forest-pool,— from the decaying 
tree-trunk, fallen into the river, and gradually yielding up 
its soluble constituents or the products of its decomposition, 
• — onward to the drainage of the cess-pool or the churchyard 
winning its way into the village well and to the sewage of 
some “ closetted ” town, contaminating the main arteries of 
a kingdom, — we find everywhere the same class of results. 
The waters are tainted by the residues of animal and vege- 
table life. The contamination is going on all around, but 
what are the means for its abatement ? Has Dame Nature 
issued a “ Rivers Pollution Commission,” and, if so, is it 
more efficient than that lately sent out by our gracious 
Sovereign ? Some self-styled authorities on this question 
fall little short of declaring that there is no natural process 
by which water, once contaminated with animal excrement 
or with putrid carcases, can be purified. With all cleansing 
operations, real or imaginary, carried on by lifeless agencies 
we have here no concern. There are certain water-plants 
