100
NOTES—ORIGINAL AND SELECTED.
organisation, there will remain but little doubt that such is the
case. This circumstance alone invests the shell with a great deal
of interest.
There is considerable difference in the shapes of individual
shells. Some are as flat and thin as, or thinner than, a native
oyster, others are so deep as to resemble in their contour
Gryphaea incurva. In some the apex of the shell, which is
carried to one side, has not otherwise destroyed the symmetry
of the shell. In others there is a tendency to a sinus on that
side.
The habits of this mollusc are sometimes at fault. In its
persistent tendency to adhere it will fasten on to a member of its
own species, to be in its turn fastened on to by another member,
resulting in death certainly to the middle one. I could only find
groups of three, but I believe a larger number sometimes occur.2
It is this persistent adherence that makes them so destructive to
the oyster spat, and on that account the dredgermen hunt them
implacably. But in the variety of shapes that these shells
exhibit there are some that appear either not to have adhered,
or, if so, to have had possibly intermittent spells, for in some
adult shells the aperture is slightly smaller than the body of the
shell, and, if anything, there is a tendency to incurve its margin,
In others the tendency is to recurve the margin, a condition
which we more generally associate with habits of adherence.—
John French, Waltham Cross.
BOTANY.
Erysimum orientale and other rare plants near
Braintree.—You may be interested to hear of an uncommon
plant that has appeared this season as a weed in my garden —
Erysimum orientale. I believe the last notice of its habitat in
Essex—as recorded in Gibson's Flora—was made by the 17th
Century Naturalist, Dr. Dale, who found it growing near
Harwich. I have only one plant, but another is springing up.
It seems to be a coast plant, and an "alien" according to
Hooker. The cottage I live in was built in 1616. Therefore
it was standing during Dale's lifetime, and as he lived
near by, at Bocking, he may have attended patients
2 Some time ago I presented to our Museum a set of eleven specimens attached one on
the shell of the other, but so far as I remember they were all alive. Indeed, they would have
fallen apart if this had not been so.—W. Cole.