sation as ova, the vitality is
preserved till the recurrence, and contact of the rain and oxygen in the
next wet season, when vivification takes place from their joint
influence."[1]

[Footnote 1: YARRELL, _History of British Fishes_, introd. vol. i. p.
xxvi. This too was the opinion of Aristotle, _De Respiratione_, c. ix.]

This hypothesis, however, appears to have been advanced upon imperfect
data; for although some fish, like the salmon, scrape grooves in the
sand and place their spawn in inequalities and fissures; yet as a
general rule spawn is deposited not beneath but on the surface of the
ground or sand over which the water flows, the adhesive nature of each
egg supplying the means of attachment. But in the Ceylon tanks not only
is the surface of the soil dried to dust after the evaporation of the
water, but earth itself, twelve or eighteen inches deep, is converted
into sun-burnt clay, in which, although the eggs of mollusca, in their
calcareous covering, are in some instances preserved, it would appear to
be as impossible for the ova of fish to be kept from decomposition as
for the fish themselves to sustain life. Besides, moisture in such
situations is only to be found at a depth to which spawn could not be
conveyed by the parent fish, by any means with which we are yet
acquainted.

But supposing it possible to carry the spawn sufficiently deep, and to
deposit it safely in the mud below, which is still damp, whence it could
be liberated on the return of the rains, a considerable interval would
still be necessary after the replenishing of the ponds with water to
admit of vivification and growth. Yet so far from this interval being
allowed to elapse, the rains have no sooner fallen than the taking of
the fish commences, and those captured by the natives in wicker cages
are mature and full grown instead of being "small fish" or fry, as
supposed by Mr. Yarrell.

Even admitting the soundness of his theory, and the probability that,
under favourable circumstances, the spawn in the tanks might be
preserved during the dry season so as to contribute to the perpetuation
of their breed, the fact is no longer doubtful, that adult fish in
Ceylon, like some of those that inhabit similar waters both in the New
and Old World, have been endowed by the Creator with the singular
faculty of providing against the periodical droughts either by
journeying overland in search of still unexhausted water, or, on its
utter disappear