latter they are, perhaps,
attracted by the sweet juices secreted by the aphides and coccidae.[2]
Such is the passion of the ants for sugar, and their wonderful faculty
of discovering it, that the smallest particle of a substance containing
it is quickly covered with them, though placed in the least conspicuous
position, where not a single one may have been visible a moment before.
But it is not sweet substances alone that they attack; no animal or
vegetable matter comes amiss to them: no aperture appears too small to
admit them; it is necessary to place everything which it may be
desirable to keep free from their invasion, under the closest cover, or
on tables with cups of water under every foot. As scavengers, they are
invaluable; and as ants never sleep, but work without cessation during
the night as well as by day, every particle of decaying vegetable or
putrid animal matter is removed with inconceiveable speed and certainty.
In collecting shells, I have been able to turn this propensity to good
account; by placing them within their reach, the ants in a few days
removed every vestige of the mollusc from the innermost and otherwise
inaccessible whorls; thus avoiding all risk of injuring the enamel by
any mechanical process.

[Footnote 1: Mr. Jerdan, in a series of papers in the thirteenth volume
of the _Annals of Natural History_, has described forty-seven species of
ants in Southern India. But M. Nietner has recently forwarded to the
Berlin Museum upwards of seventy species taken by him in Ceylon, chiefly
in the western province and the vicinity of Colombo. Of these many are
identical with those noted by Mr. Jerdan as belonging to the Indian
continent. One (probably _Drepanognathus saltator_ of Jerdan) is
described by M. Nietner as occasionally "moving by jumps of several
inches at a spring."]

[Footnote 2: Dr. DAVY, in a paper on Tropical Plants, has introduced the
following passage relative to the purification of sugar by ants:

"If the juice of the sugar-cane--the common syrup as expressed by the
mill--be exposed to the air, it gradually evaporates, yielding a
light-brown residue, like the ordinary muscovado sugar of the best
quality. If not protected, it is presently attacked by ants, and in a
short time is, as it were, converted into white crystalline sugar, the
ants having refined it by removing the darker portion, probably
preferring that part from it containing azotized matter. The negroes, I
may remark,