Journal of Proceedings.
xi
had captured it on the forest at the back of Paul's Nursery, near High
Beach. This form appears to be rare all over the kingdom, and, so far
as Mr. Cole was aware, had not before been noticed in Epping Forest.
Willingale was well acquainted with the haunts of the Adder in the
forest, and had been accustomed to catch them for years, but had never
previously noticed one like the specimen exhibited.
Mr. White showed a specimen of the common London moth, Biston
hirtaria, with only one pair of wings, it having been bred from the
chrysalis in that state of dismemberment. Referring to this not un-
common occurrence among moths and butterflies, Mr. W. Cole alluded
to the hypothesis put forward some time ago to account for it, viz. : that
the attacks of internal parasites were the primary cause of such mal-
formations. In most cases of "stung" larvae the parasites (Ichneumon-
flies and creatures allied in habits to them) were in sufficient numbers
to kill off the unfortunate caterpillar just as it was preparing for the
pupal stage ; but supposing from some cause only one or two eggs of
the parasite had been deposited in the caterpillar, it was conceivable
that no vital injury would be done to the "host," with the exception of
the destruction of some parts of the undeveloped tissues, possibly
an embryo leg or wing, which being destroyed would compel the
(im)perfect insect to come into the world minus such members,
although in other respects quite capable of all the functions of life.
Mr. N. F. Robarts exhibited a flint implement found by himself on
Dartmoor, and offered some remarks upon it.
Mr. E. Charlesworth exhibited a large number of drawings and
engravings of objects of Natural History, many of them relating to
Essex ; and in connection with one of them (a drawing of the jaw of
Mosasaurus found in the chalk at Grays) he made some observations
criticising Mr, Bowerbank's theory of the origin of the distinct beds or
bands of flints traversing the chalk.
Prof. Boulger exhibited on behalf of Mr. John Gibbs, of Chelmsford,
two abnormal specimens of the common Wallflower and Polyanthus, and
read the following extracts from a letter recently received from Mr.
Gibbs:—
" One of the specimens is a Wallflower in which the stem divides in
such a manner as might be called dichotomous, but I suppose it will be
understood as a case of fasciation. Without the gyrate form of Myosotis
the arrangement of its flowers seems very much like what we find in that
genus, and would appear to favour the opinion entertained by the Rev.
George Henslow that the inflorescence of that and other genera of
Boragineae is really racemose.
" My other enclosure is a Polyanthus (Primula) in which two corollas
are contained in one calyx, a phenomenon which, I think, is not sup-
posed ever to occur except abnormally. But as what is in the first
instance abnormal may be propagated by seed, and so become charac-
teristic of a new form, am I at liberty to imagine the possibility of such
a form being perpetuated ? in which case the calyx would become an
involucre, and the corolla a perianth. We should then have a new