The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1891-08-30
SPINY SEA URCHIN.
Delicacy Little Esteemed by Pu.
get Sound Clam-Eaters.
A SHELL OF 600 PIECES.
Greeks and Romans Ate the Fine Mol.
iusk-'Food Fit for the Gods"
Says Louis Figuier.

PoRr TOWNSEND, Aug. 25.-[Special Cor
respondence. Along the shores of the
salt water of Puget sound. and especially
on fuea strait and at Cape Flattery, may
be found an interesting mollusk. COM
monty called sea eggs, or sea porcupine.
from Its prickly spines. The shell of this
moliusk is of flattened globular. or dome
shape, but extremely variable in form.
The variety most common in our waters
Is the Echinu esculeatns Lamarck), VARYING
In size from two to six inches across its
lower patln and from one to three inches
TO the top of the dome. The shell is one
OF the most marvellous structures of the
animal kingdom; it is not in one solid
piece, like the shell of the oyster or clam,
but is composed of a vast num-
Der of separate pieces of
hexagonal or pentagonal shape
adhering at their edges. More than 600 of
these pieces, each admirably arranged and
united, enter into the composition of the
smell of the sea urchin. A vascular tissue
passes up between the joints where one
meets another and spreads itself over the
"hoie OF the exterior surface The glands
Oh the lnverting tissue secrete lime from
the sea water, and deposit after a deter
inmate and orderly pattern on every part
OF the surface Thus the inner face, the
outer lace and each side and angle of the
poiyhedron grow equally together. and the
form characteristic of the individual ia
maintained with immurtable mathemat-
lcal precision. If fresh
and perfect specimen be examined
the surface is seen TO be covered with
short, sharp spines, so thickly set that
the substance of the shell can scarcely be
seen. The structure of these spines is
very remarkable, and under the micro
scope they present some most interesting
details. Each of these spines is movable,
at the will of the animal, and works upon
a true ball and socket joint, the ball being
a round globular projection on the surface
of the shell and the socket set into the
base of the spine. There is no shell that
exists more admirably symmetrical, ele-
CANT, or more highly ornamental than the
corona of the sea urchin.
Viewed through powerful lens or mag
nifying glass it will be seen that the entire
surface is covered with alternate rows of
the globular projections for the spines to
rest upon, and minute holes through
which the nervous system in connected
from the interior, by means of which the
animal has perfect control of the move
ments of its spines, which are at once a
means of defense and of locomotion. The
attachment of the spines is very slight,
and when the creature is dead they
are easily removed. The spines on
the lower portion of the shell
are the umbulacral feet and by their means
the creature is enabled to move from place
to place. When it is considered that each
of these spines is put in motion by several
muscles it is astonishing to consider the
prodigious number of organs brought into
action by single sea urchin. More than
], 200 spines have been counted upon the
shell of the Echinus escuLentus If we add
other smaller and in some sort accessory
spines, we shall find total of 8, 600 prickles.
Add to these the ambulacral feet in each
series of which not, less than 100 can be
found, and we will find total of 1000 ap-
pendages upon the body of an animal of
very small proportions.
These shells are common on all the salt
water beaches of Puget Sound at certain
seasons, particularly during the summer
months, when the Indians collect quanti-
ties of them for food. The empty shells
are very fragile and easily broken, but
when perfect are eagerly collected by chill
dren and adults as objects of curiosity and
ornament.
To watch the creature in the act of walk
ing is most interesting, particularly in an
aquarium. If the observer will take a
magnifying glass and examine the under
surface of the shell. he will see that be-
tween the spines of the feet il is studded
with vast number of tiny projections
called pedicellaria. Their stems are
hardly thicker than hair and
their tips are furnished with round
knots, or, in many instances, with these
>ANsilMI