perfectly visible inside, distending its
swallower into unwonted forms, for the time, like
a stick thrust into an elastic bag too small to
hold it without stretching. It is as if some
herbivorous whale were to gorge itself with
a palm-tree without previous mastication.
This is droll to see; but the grand
disappointment remains. My interesting insects
are only confervoid algæ, a tribe of simple
plants, gifted with oscillatory motion.

Let us try the results of another day's
fishing:

This choice sample of water is selected
from the depths of an ancient and overgrown
wheelrut, where it has remained stagnant for
some time past. The water itself is clear;
but that nearest the surface, as seen through
the bottle against the light, is slightly tinged
with green, as if a camel's-hair pencil
containing a drop of green water-colour had
just been dipped in it. With a quill cut into
the shape of a blunt picktooth, I take a drop
from the tinted stratum, and spread it on a
slip of glass. And now remark the
consequence of my thus disturbing the water with
the quill. The green colouring matter
descends in little clouds to the bottom of the
phial, like so many shoals of little fish
alarmed by a stone being thrown into their
pond, or like flocks of pigeons making their
escape from a hawk. The simile is actually
correct, and the simultaneous descent of the
clouds is the most remarkable circumstance
of the case; for, observe our drop in the
microscope, and you perceive a multitude of
creatures in motion, swimming hither and
thither with great activity. Their form is
that of bright green mulberries composed of
numerous emerald grains, and enclosed in a
colourless, transparent, gelatinous envelope.
They rotate on their axis and travel forward
at the same time, imitating in a small
way the motion of the planets. But although
all globular, they are not all exactly
alike. Some, look like families of crystallised
fruits that had met together in a spherical
house of glass, and had then commenced
their circling round, in imitation of dancing
dervishes. There are small and big
mulberries, there are baby whirligigs and giant
ones, as well as the associated merry-go-
rounds. These organisms, as I will
cautiously style them, are Volvoxes, aptly so
termed, otherwise notorious as globe-animalcules.
There is a whole family, Volvocinæ,
of which the genus Volvox can boast of but
one species, V. globator, which is satisfactorily
established. It is often found in great
abundance, and, attaining a diameter of one-
thirtieth of an inch, it appears to the naked
eye as a minute green globule gently moving
about in the water. It rolls over and over
during its progress with a motion which a
moderate magnifying power shows to be
caused by the vibration of innumerable cilia
or bristles arranged upon the surface of the
globe. This self-bowling cricket-ball was
long looked upon as a very formidable aquatic
monster; it excited the wonder and
admiration of those patriarchal observers
Leeuwenhoek (its first discoverer) and
Spallanzani. Some volvocinæ were said to be
furnished with eyes. Ehrenberg considers
them as monads, and describes them as
naked, many-stomached, entrail-less animalcules,
furnished with a long trunk and a
variety of internal organs. Others style
them animals without appreciable internal
organisation, and without a mouth. Recent
writers, however, cut short our speculations
on the animal biography of the whole Volvox
tribe, by insisting that there can now be no
doubt of the vegetable character of that
composite structure, that collection of organisms,
that rotatory nest of boxes, which was long
supposed to be a single animal. In short,
we are treading on the border-land of life;
and it is not easy, especially at first sight, to
perceive the boundary line which separates
plants from animals.

The best authorities agree in telling us
that, in the present state of science, it would
be very difficult, and is perhaps impossible,
to lay down any definite line of demarcation
between the two kingdoms. Many portions
of this border-country have been taken and
re-taken several times; their inhabitants
having been first considered, on account of
their general appearance, to belong to the
vegetable kingdom; then, in consequence of
some movements being observed in them,
being claimed by the zoologists; then, on
the ground of their plant-like mode of
growth, being transferred back to the
botanical side; then, owing to the supposed
detection of some new feature in their structure
or physiology, being again claimed as
members of the animal kingdom; and, lastly,
on the discovery of a fallacy in those
arguments, being once more laid hold of by the
botanical leaders, with whom, for the most
part, they now remain safe prisoners. For,
the attention which has been given of late
years to the study of the humblest forms of
vegetation, has led to the knowledge of so
many phenomena occurring amongst what
must be undoubtedly regarded as plants,
which phenomena would formerly have been
considered unquestionable marks of animality,
that the discovery of the like phenomena
among the doubtful beings in question, so far
from being any evidence of their animality,
really affords proofs to the contrary.

It is not now, as was formerly supposed,
the presence, or the absence, of spontaneous
motion, by which the animal or vegetable
nature of any organism can be tested. The
germs of many waterweeds have the power
of moving freely for a time, till they adhere
to some solid object—a rock, or a ship's
bottom—germinate, and become fixed plants;
so that the same individual would be an
animal at the first stage of its existence,
and a plant at the second. These erratic