analogous to ivliat has been observed, though of course on a
scale much smaller in portions of freshivater, that the one
can scarcely be considered complete without a reference to the
other, and both are of the highest interest. In the “ Annales
des Sciences Naturelles,” 3d Series, t. ii., there is an
able and elaborate memoir hy Dr. Montagne, one of the first
Cryptogamie Botanists of Europe, “ S u r la Phénomène de
la Coloration des Eaux de la Mer Rouge,” Avhich contains
a great number of references to Avorks in which mention
has been made of the phenomenon of the colouration of the
sea.
The sudden and periodical colouration of vast extents o f
the sea, has been, to uninformed minds, in early times, a subject
o f superstition and dread, these appearances having been
regarded by the ignorant as Divine manifestations of anger
or impending calamity ; and that they should have been so
regarded in days in Avhich natural science was all hut un-
knoAvn, is scarcely surprising. The true explanation o f the
cause o f these sudden and remarkable appearances, Avhile it
removes all feelings o f superstition or dread, does not banish
those of amazement and admiration Avhich indeed supplant
them.
The following appropriate observations in the memoir of
Montagne, already referred to, occur : —
“ The singular phenomenon of the colouration produced on
the surface of the Red Sea, — a colouration in which we
have seen the waters themselves do not participate, has
been, each time tha t it occurs, a ncAV subject of astonishment
for the people who have witnessed it. I t cannot be
doubted, moreover, tha t the jugglers and charlatans, after
having probably calculated in advance its periodical return,
made use of it to govern the multitude by the menace
of an approaching calamity, of which they failed not to present
this sign as the undoubted precursor. I t is also to a
cause, if not altogether similar, at least very analogous, that
is to be attributed, according to many naturalists, in the
number of whom figures M. Ehrenherg, those rivers, waters,
and lakes changed into blood In one of the plains of Egypt,—
an explanation which M. Morren considers somewhat hazardous,
although not improbable. As to the phenomenon of the
Red Sea, hy the fact that its extent has impressed upon it a
character of majesty calculated to affect strongly the imagination
of the vulgar, it ought to produce still more sensation.
Since now we know the origin of it, if we compare together
the Immensity of this phenomenon, and the infinite smallness
of the being which produces it, one cannot divest oneself
from a profound sentiment of admiration for the Omnipotence
Avhich effects such great ends with such feeble means.”
Section i.
Filaments not enclosed in gelatine o f a definite form.
32. S P IR IL L U M DAr.
Char. Filaments spiral, æruginous green.
1. Spirillum J en neri Hass.
P late L X X V . Fig. 5.
Char. Filaments rather thick, each being usuallg composed o f
about eight or ten regular spiral coils. Striæ distant, perceptible.
Hah. Tunbridge: Mr. Jenner.
This is the finest species of the genus. I have not seen a
pure specimen, those sent me by Mr. Jenner being mixed
up with different species of Oscillatorioe.
2. Spirillum rupestre.
Plate L X X V . Eig. 6.
Char. Filaments slender, regularlg spiral.
Oscillatoria spiralis Carm.
Hab. On rocks by the seaside where the birds are in the
habit of resting, Appin : Capt. Carmichael.
T 3