uently a pair of these bodies were attached to each other,
as represented above, cone beside cone, at that end where the
septum occurs.

I will here add a few other observations connected with the
discoloration of the sea from organic causes. On the coast of
Chile, a few leagues north of Concepcion, the "Beagle" one day
passed through great bands of muddy water, exactly like that of a
swollen river; and again, a degree south of Valparaiso, when fifty
miles from the land, the same appearance was still more extensive.
Some of the water placed in a glass was of a pale reddish tint;
and, examined under a microscope, was seen to swarm with minute
animalcula darting about, and often exploding. Their shape is oval,
and contracted in the middle by a ring of vibrating curved ciliae.
It was, however, very difficult to examine them with care, for
almost the instant motion ceased, even while crossing the field of
vision, their bodies burst. Sometimes both ends burst at once,
sometimes only one, and a quantity of coarse, brownish, granular
matter was ejected. The animal an instant before bursting expanded
to half again its natural size; and the explosion took place about
fifteen seconds after the rapid progressive motion had ceased: in a
few cases it was preceded for a short interval by a rotatory
movement on the longer axis. About two minutes after any number
were isolated in a drop of water, they thus perished. The animals
move with the narrow apex forwards, by the aid of their vibratory
ciliae, and generally by rapid starts. They are exceedingly minute,
and quite invisible to the naked eye, only covering a space equal
to the square of the thousandth of an inch. Their numbers were
infinite; for the smallest drop of water which I could remove
contained very many. In one day we passed through two spaces of
water thus stained, one of which alone must have extended over
several square miles. What incalculable numbers of these
microscopical animals! The colour of the water, as seen at some
distance, was like that of a river which has flowed through a red
clay district; but under the shade of the vessel's side it was
quite as dark as chocolate. The line where the red and blue water
joined was distinctly defined. The weather for some days previously
had been calm, and the ocean abounded, to an unusual degree, with
living creatures. (1/9. M. Lesson "Voyage de la Coquille" tome 1
page 255, mentions red water off Lima, apparently produced