the rotifera

wlieel-like or indented particles moved in a circle, at tlie same time out of a clear and
transparent place a little round particle appeared, which, without nicely viewing, could
hardly be perceived; which particle growing larger, moved with great swiftness as it
were about its own axis, and continued without any alteration in its place, till the
animalculum had drawn part of its body back into its sheath ; in doing which it placed
the said round particle on the edge of its sheath, which thus became augmented with a
round globule; and whereas the animalculum had placed the said globule on the east
part of its sheath, another time it fixed it on the south or north side; by which means
the sheath was regularly increased on all sides."
Of course this is but a rough sketch of the machinery and actions of the famous tubemaker
; but it is a vigorous one, and true to the life as far as it goes.
With equal truth and vigour does Leuwenlioek describe, in the same paper, the
transformations of Philodina roseola ;—that creature, whose powers of lying dormant for
rotiferous ages, and of then coming to life again, have made it as famous as the " Seven
Sleepers."
To anyone with a sense of humour it must be delightful to read the following paragraphs
of Leuwenhoek's paper; and then to reflect how his discoveries have been repeatedly
re-discovered; and how again and again they have been challenged, confirmed,
forgotten, and once more discovered. In fact, the Pliilodine has been the
cause of a dispute which has all the marvellous properties of the Rotiferon itself. For it
periodically goes to sleep and revives again, just as P. roseola does; but with a difference.
The Rotiferon, when it awakes after its long sleep, takes up its life at the point where it
left it off; and ultimately " gives up its murmuring breath " after an existence of three or
four years; but the dispute concerning it invariably begins again both de novo and de
ovo; and having already lasted, with periodical intermissions, for nearly 200 years,
evidently bids fair to last for 200 years more ; as it has only a short time ago awakened
once more, as fresh and as vigorous as ever, and found its way into our daily papers.
" I discovered," says Leuwenlioek, " several animalcula that protruded two wheels out
of the fore-part of their body as they swim, or go on the sides of the glass. . . . This sort
I found, in great numbers, in the gutter water which had stagnated some days in the small
pits or cavities of the lead. ... In October 1702, I caused the dirt of the gutters, when
quite dry, to be gathered together, and taking a small quantity of it, I put it into a paper
on my desk; since which time I have often taken a little of it, and poured on it boiled
water after it had stood still till it was cold, that I might obviate any objection that
should be made, as if there were living creatures in that water. These animalcula, when
the water runs off or dries away, contract their bodies into a globular or oval figure. . . .
In the month of September I put a great many of the last-mentioned animalcula into a
wide glass tube, which presently placed themselves on the sides of the glass ; whereupon,
pouring off the water, I then observed that several of the animalcula, to the number of
eighteen or nineteen, lay by each other in a space of coarse sand; all of which, when
there remained no more water, closed themselves up in a globular figure. Some of these
animalcula were so strongly dried up that one could see the wrinkles in them, and they were
of a reddish colour; a few others were so transparent, as if they had been little glass
balls, that, if you held them up between your eye and the light, you might move your
fingers behind them, and see the motion through their bodies. After these animalcula
had lain thus dried up a day or two, in an oval or globular form, I poured some water
into the glass tube; whereupon they presently sank to the bottom, and after the space of
about half an hour began to open and extend their bodies, and, getting clear of the glass,
to swim about the water. ... In the month of October, before the dirt of the leaden
gutter was quite dried up, I took a handful of it, and laid it on a glazed earthen dish in
order to preserve it. . . . Upwards of twenty-one months after, I took some of this dry
stuff and infused it, both in cold water that had been boiled, and in rain water newly
fallen ; whereupon the animals began to show themselves in great numbers."
The only points of this much vexed question that Leuwenhoek passes over are :
http://rcin.org.pl