Nature's Scavengers . 
[April, 
176 
it appears that there are among animals three distinct 
classes or grades of scavengers : — those which bury refuse, 
whether for the food of themselves and their offspring, or 
simply to avoid a nuisance ; those which destroy offal by 
devouring it, but do not taint other matters; and, lastly, 
those which devour putrid matter, but, being at the same 
time omnivorous and obtrusive, diffuse the germs of putre- 
faction and disease. Towards these three classes respectively 
reason demands that we should assume a very different 
attitude. The scavenging creatures of the first class we 
should cherish, defend, and seek to multiply. Those of the 
second, provided they have no especially dangerous proper- 
ties, like the wolf or the hyaena, we may tolerate, and in 
scantily peopled and semi-civilised countries we may even 
protect. Thus, wherever sanitary appliances are imperfect, 
it is good policy to preserve vultures, carrion crows, &c., by 
legal enactments. Against the third class, which diffuse 
septic poisons, and which prey upon sound and useful 
matters, we must wage an unrelenting and systematic war. 
We have observed that not every kind of nuisance finds, 
in the economy of Nature, some animal expressly adapted 
for its removal, especially in a perfect manner. There is no 
inseCt which buries human ordure, or that of the Carnivora. 
If, at least, such a process ever takes place it is rare and 
exceptional. The dissolved impurities of the water are not 
met, especially when excessive, and the solid impurities of 
the atmosphere seem equally overlooked. Further, we find 
one and the same nuisance attacked by scavengers of all the 
three classes. A dead bird may engage the attention at 
once of Necrophori , Silphce, and blow-flies ; or a piece of ex- 
crement be visited at once by Geotrupidae, Brachelytra, and 
dung-flies. Now, what should we say of an army where 
part of the troops were equipped with breech-loaders, part 
with muzzle-loaders, and part with matchlocks, or bows and 
arrows ? What would be our comments if the commanders 
of the army were most solicitous to keep up the number of 
the matchlock men, whilst allowing the regiments armed 
with the breech-loaders to decrease ? Or what should we 
think of a carrier who should employ, between the same two 
points, goods-trains, stage-waggons, and pack-horses, giving 
constantly a larger and larger proportion of the traffic to the 
latter ? Yet these two imaginary cases are exaffily parallel 
to what we find in the disposal of offal. Nature’s sanitary 
service does not form a well-organised system in which pro- 
vision is made for every kind of nuisance, and where every 
task is committed to that creature only which is capable of 
