working out of the universal problems of nature. Neither a collector nor
a scientific student, my attitude towards marine objects is that of a
mere observer--an interested and often wonder-struck observer--so that
when I classify one species of mollusc as common and another as rare I am
judging them in accordance with my own environment and information, not
from a general knowledge of one of the most entertaining branches of
natural history. From this standpoint I may refer to four or five species
which stand out from the rest in interest and comparative rarity.

An oyster (OSTREA DENDOSTREA FOLIUM), too mean of proportions, too dull
and commonplace of colour to be termed pretty, worth nothing, and
justifying, in appearances its worthlessness, is remarkable for the
exercise of a certain sort of deliberate wit in accordance with special
conditions. Nature provides various species of the great oyster family
with respective methods of holding their own in the sea, and in the case
under review she permits the individual to exercise a choice of two
different methods of fixture as chance and the drift of circumstances
decide its location. From the bases of the valves spring three or more
pairs of hook-like processes which, if Fate decides upon a certain coral
host, encircle a slim "twig," creating for the mollusc a curious
resemblance to a short-limbed sloth hugging tightly the branch of a tree.
When the spat happens to settle in places where coral is not available
the hooks or arms are but crudely developed. It becomes a club-footed
cripple, its feet adherent by agglutination or fusion to a rock or other
and larger mollusc, dead or alive. In fact, the shrewd little oyster
responds to its environment, clasping a twig with claws or cementing
itself to an unembraceable host in accordance as contingencies insist.

Another mollusc (AVICULA LATA), sometimes found in company with the
clinging oyster, resembles, when the fragile valves are expanded, a