The Sun.
London, England, 1864-08-18 00:00:00

Spontaneous Generation.

M. Pouchet replied last week to M. Coste, who, it may
be remembered, read a paper about three weeks ago to s how
that the theory of spontaneous generation rested upon eisro-
neous or insufficient experiments. M. Pouchet's prese rat
paper is perhaps one of the most interesting documents con-
nected with this curious debate, which is now in the ftfcit
year of its existence. M. Coste, our readers may recollect,
had, after stating that when a certain quantity of hay was
left to macerate in water, a pellicle was founded on the sur-
face, asserted that that pellicle was not a proligerms aft ooze
i.e., that it did not generate monads, vibrios, or bacterias
(all animalcules) as M. Pouchet affirmed; because these
infusoria made their appearance in the liquid before the pel-
icle was formed. To this it. Pouchet replied that the lat-
ter is the real generator, but Oat some infusoria do mike
their appearance in the liquid beiere the pellicle; the infer-
ence, however, which M. Coate dre ws from this fact h
declares to be erroneous. A meadow is but an immense
field of maceration where incalculable legions of infusoria.
pullulate. their eggs and kysts sock to the stacks and
leaves of the graminaceous plants that constitute hay,
and may produce animalcules almost. as soon as the latter
is put into water. So far, Yi Caste's observation
is perfectly exact; and the only difference of opinion
between him and M. Pouchet lies in the number of these
infusoria, which is exceedingly small compared to that of
the animalcules issuing from the proligerous etroma. More-
over, the former play uo part in M. Pouchet's experiments,
because these large iufusuria, which sometimes appear in
the course of a few hours in the water of maceration, die as
soon as fermentation is developed in the liquid, which there.
fore acquires new chemical properties. Moreover those in-
fusoria are in almost every case absolutely different from
those produced by the proligerous pellicle. Besides, if the
liquid be filtered, those large species are eliminated from it,
so that there can be no doubt about it. If we put a consider•
able quantity of hay into a large receiver and fill it with
water up to the neck, at a mean temperature of 25 deg.,
there will be no fermentation for three or four days, and
daring that time no proligerous pellicle will be formed. On
examining the liquid, very few bristly microzoaria will be
perceptible. If, on the contrary, by the aide of this receiver
we put another vessel having a large surface, with only ten
grammes of hay in it in 250 grammes of water, a thick pro-
ligerou-s membrane will be formed in the course of three
days, and will be seen to contain an immense population
of bristly or ciliated infusoria. If M. Costa's observations
were correct, the contrary would bs the case. M. Pouchet
further reminds M. Coste that he (our author) has ob-
tained large ciliated infusoria from bay that had been
boiled; from Lolled crabs, that had remained half-an-
hour in boiling water; from the maceration of the skulls of
Egyptians taken from the graves of Thebes ; from the
maceration of the eggs of a python, from the eggs of a
Tonle Serrate, from linseed-oil raised to the temperature
of 200 deg. Centigrade, and from secular dust almost car-
bonised at a temperature of 280 degrees. M. Pouchet fur-
ther denies M. Coste's assertion that bristly infusoria will
pass through even three filters at the museum of Rouen M.
Pouchet has never seen a bristly animalcule pass even
through a single filter, or even its eggs or kysts pass
through. And, indeed, what is the diameter of the large
bristly microzoaria, which are usually the objects of ex-
periment ? It varies between five-hundreths of a milli-
metre, and one-tenth of a millimetre. What is the diameter
of their eggs ? According to M. Balbiani himself, it varies
between 15 thousandths of a millimetre and two hundredths
of a millimetre. And what, on the other hand, is the
diameter of the pores of paper? Three thousandths of a
millemetre at the utmost. Now it is mathomaticalsy im-
possible that a body varying between one-tenth and fifteen-
thousandths of a millimetre should be able to pass
through a pore of not more than three-thousandths of a
millimetre. P.S. Coate says that the infusoria squeeze
themselves through the paper and become like threads;
but even this is not admissible, since their stomachs
alone have a diameter of six-thousandths of a
millimetre. Some infusoria, M. Pouchet admits, do pass
through filters; he published 'hat fact himself long ago ;
and, to prevent its occurrence, he has sometimes used as
many as ten filters ; but never by any chance is this the
case with bristly infusoria. Far from their passing
through filters; kolpodes do not even resist porpbyrization.
A;gramme of his infusoria was ground on porphyry for
the space of two hours, and the produce was divided into
parts, one being kept in a glass, and the other filtered. The
first portion only produced monads; the filtered one, on
the contrary, yielded nothing but en innumerable quantity
of vorticelles ; as for kolpodes, they were nowhere to be
seen. M. Pouchet repels M. Coste's supposition that he
could have mistaken enkysted microzoaria (a e., in the state
of a chrysalis) for spontaneous eggs. The latter are clear,
transparent, and filled with very minute granulctions ; it
is smaller than an enkysted animalcule, and offers no trace
of interior organs. After passing through a stage of per-
fect immobility, the yolk begins to whirl round, and one
can see that this motion takes place inside the envelope,
which has no bristles. After this, the punetum *titans
makes its appearance ; its motions cannot be mistaken for
those of the heart of an enkysted animalcule. Then come
the embryonal motions, and the animal issues from its egg.
The bristly animalcule, on the contrary, on becoming
enkykted, presents very distinct internal organs; it has
digestive apparatus, its nucleus, and circulating apparatus.
Its gyrations, which are a real agony in its case, last but
little; they are irregular, and performed by means of the
outer bristles, which move. The pulsations of the heart
are rapid. The production of the spontaneous egg is so in-
timately connected with the existence of the proligerous
membrane, that it is never suet with without it—and this
egg is so far from being an enkysted animalcule, that it is
discovered in its strotua before any of those infusoria that
are supposed to have generated it. M. Pouchet denies that
tardigrades, as M. Doyere maintains, can bear a heat of 140
deg. cent. ; he states 90 as the outside. In one single in-
stance, he admits, wheel-animalcules were able to resist the
temperature of boiling water for a few minutes—but that
was, he satirically remarks, because the observers relaxed
from their rigour, He concluded with reminding the
academy that infusoria had ere this been found in the
human blood,a fact which he considered one of the strongest
proofs of spontaneous generation—for how could infusoria
get into the blood-vessels, which are hermetically closed
everywhere, if they had not been spontaneously generated
I therein ?

MARKETS—This Day.