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his rather slender style of entertaining.
Then he added: "Suppose we go up to
the ladies now."


NEARLY two years ago, a paragraph
appeared in the Illustrated London News,
stating that Dr. Francis Day, the well-
known Indian ichthyologist, had transmitted
to the Zoological Gardens a number
of "walking fishes." We learnt that they
started by the March (1868) steamer from
Madras; but, although we regularly read
the list of passengers and arrivals by the
overland route, we never heard any more
of the fate of these fishes until the
Proceedings of the Zoological Society for 1868
happened to come under our notice a few
days ago. As, probably, few of our readers
study these proceedings, we will give a brief
abstract of Dr.Day's explanation of the
habits and manners of the singular
creatures in question.

In the first place, we may observe that of
the nineteen specimens of ophiocephalidæ,
or "walking fishes," that started from India,
only six arrived alive at the place of their
destination, on the 21st of May; and these
were not in good condition, and did not
long survive.

Most fishes respire the air which is held
in solution in the water by which they are
surrounded, and, except in special cases,
find this supply sufficient. But there are
others which may be called compound
breathers, which never obtain air for any
length of time from the water alone, but
require it direct and undiluted from the
atmosphere; and, however cool and well-
aërated the water may be, these others are,
if unable to inhale free air, simply drowned.
These phenomena are more easily seen in
India than in England, in consequence of the
difference of temperature; but even here, in
hot summer weather, carp may often be
seen with the mouth out of water and open,
while the gills are at the same time in
constant motion. Loaches and some other
fishes, chiefly inhabiting the mud at the
bottom of ponds, sometimes rise to the
surface, and, instead of inhaling, expire a
bubble of air, which has doubtless had its
oxygen more or less abstracted, and was
no longer fit for respiration. More often,
however, these fishes rise to the surface to
swallow air, some of which passes through
the intestine, and is discharged by the vent,
the mucous membrane of the alimentary
canal thus acting as an assistant respiratory
membrane. The air thus discharged has
been analysed, and found to contain an
excess of carbonic acid in place of oxygen
gas, just as is the case in ordinary exhaled
air. In India, Dr.Day has not observed
this strange process of intestinal respiration.
The purely water-breathing fishes can live
without rising to the surface, unless under
special circumstances, while the compound
breathers expire after a longer or shorter
period. Mr. Boake, whose singular
researches on the nest of the crocodile
were noticed in a recent number of The
Zoologist, placed air breathers (as he
terms the compound breathers) and water
breathers in the same aquarium, across
which, an inch below the water, he placed
a diaphragm of net, so that the fishes could
not rise to the surface. The result was
that the water breathers were unaffected,
while the air breathers died. Dr.Day
observes that the difference in the kind of
breathing of the two classes of fishes, is very
apparent when they are lying side by side
on the moist sand at the bottom of an
aquarium. The water breathers keep their
gills in constant excited motion, while the
compound breathers scarcely move their
gills, but at intervals rise to the surface,
open their mouths, and take in air.
Dr.Jerdon, a well-known Indian naturalist,
kept some of the climbing perch (anabas
scandens) in an aquarium, and observed
that, while they were generally very sluggish,
they would every now and then make
a spring to the top, to obtain a mouthful of
air: after which they dashed down again
to the bottom.

Mr. Boake gives a very remarkable
account of the mode in which certain fishes,
living in mud and requiring to ascend at
intervals to the surface, are captured in
Ceylon. As his description is published in
an Indian journal, not readily accessible to
ordinary readers, we shall offer no apology
for copying Dr. Day's somewhat long
extract from it. In the part of Ceylon to
which he refers, swamps abound, covered
with rank grass, forming a sod sufficiently
firm to support men and cattle, which move
freely on it. Between this sod and the true
terra firma, is an intermediate layer, two
or three feet thick, of diluted mud of about
the consistence of thick pea soup; and in
this mud are the fishes, which are caught in
the following manner:

"When the swamp is in a proper state for
such operations, a native goes out when the
air is still, and walking through the swamp