When very much magnified, this animalculum feems to have
fome relation to the vorticella focialis, as feen with the naked eye.
It confifts o f cryftalline molecules, difpofed in a fphere, and
filling up the whole circumference; they are all of an equal fize.
Whether they are included in a common membrane, or whether
they are united by one common ftalk, as in the vorticella focialis,
has not been difcovered. We are alfo ignorant o f the exaft
figure o f the little particles o f which it is compofed; when a very
large magnifying power is ufed, fome black points may be discerned
in the center of the cryftalline molecules. The motion is
fometimes rotatory, fometimes from right to left, and the contrary.
It is found where the chara vulgaris has been kept. ■
19. Volvox Sphasricula.
Volvox fphaericus, moleculis fimilaribus rotundis. Spherical
volvox, with round molecules.
This fpherule is formed o f pellucid homogeneous points, of different
fizes. It moves ftowly about a quarter o f a circle from
right to left, and then back again from left to right.
20. Volvox Lunula.
Volvox hemifphaericus, moleculis fimilaribus lunatis. An
hemifpherical volvox, with lunular molecules. Fig. 7, Plate
XXV.
Is
Is a fmall roundilh tranfparent body, compofed o f innumerable
molecules, homogeneous, pellucid, and o f the Ihape o f the moon
in it’s firft quarter, without any common margin.
It is in a continual twofold motion ; the one o f the whole mafs
turning ftowly round, the other of the molecules one among the
other. They are found in rnarfhy places in the beginning o f
fpring.
21. Volvox Globator.
Volvox fphaericus membranaceus. Spherical membranaceous
volvox.
This is a tranfparent globule, o f a greenilh colour; the foetus
is compofed o f fmaller greenifh globules. It becomes whiter and
brighter with age, moves ftowly round it’s axis, and may be perceived
by the naked eye.
But to the microfcope the fuperficies o f this pellucid membrane
appears covered with molecules, as if it were granulated, which
has occafioned fome obfervers to imagine it to be hairy; the
round pellucid molecules that are fixed in the center are generally
largeft in thofe that are young. The exterior molecules may be
wiped off, leaving the membrane naked.
When the young ones are o f a proper fize, the membrane
opens, and they pafs through the fiflure; after this, the mother
melts away. ^ They fometimes change their fpherical figure, the
fuperficies being flattened in different places.
3 N 2 Moft