256 THE ESSEX FIELD CLUB.
Stone Axe from Doddinghurst, Essex.—He also exhibited a polished
stone axe from Doddinghurst, which was figured and described by Mr. F. W.
Reader in the Essex Naturalist (ante p. 193).
Palaeolithic Flake from Kelvedon, Essex.—Mr. W. Whitaker, F.R.S.,
exhibited and presented to the Club a Palaeolithic "worked" flake, found during
the excursion to Kelvedon on July 4th last (ante p. 249).
Varieties of Helix Nemoralis.—Mr. J. T. Winkworth exhibited a fine
series of "varieties" of the "Girdled Snail," Helix nemoralis, mostly from the
neighbourhood of Harlow, Essex, and made the following observations on the
specimens :—
VARIATIONS OF HELIX NEMORALIS AT HARLOW, ESSEX.
The exhibit goes to emphasize the wide and handsome variations of the mollusc.
All the shells exhibited, with the exception of var. olivaceae were gathered
near Harlow, off the bank bordering the main road from Epping to Bishops
Stortford.
The series consists of the following variations :—
(I) Yellow—Ia yellow, with a single central black band ; Ib yellow, with
many black bands.
(II) Red—IIa red, with single central red band ; IIb red, with many black
bands.
(III) Whitish, with black bands varying in number.
(IV) Whitish, with black bands merged, forming almost a black ground.
(V) Pinkish or flesh-coloured.
(VI) Olive ; known as var. olivacea, of uniform rich olive colour.
(VII) Single banded ; band varying in width.
Helix nemoralis is remarkable for the absence of the normal number of bands,
and the mollusc seems to assert its discipline of the pigmentary-glands with the
increase of age up to the end of the shell depositing period, so that apologetic
bands or beginnings of bands are in evidence near the lip while no suspicion of
the lines are observable in the older parts of the shell.
On the other hand occasionally an extra line is seen, so that the normal
1, 2, 3, 4, 5, becomes 1, 2, 3, 4, 5, 6.
Many interesting facts forced themselves on one's attention while in search of
these shells. As a rule they were well concealed in grass or among leaves, only
discovering themselves freely after considerable rain. Helix hortensis on the other
hand can always be found on leaves and stems of hedges or on stalks on grasses
and other vegetation. I found it necessary usually, where any were to be found,
to feel over all the low lying grass.
The yellow forms and yellow with varying bands, were common in dried
grass, while the red or reddish-brown forms were found among dried
leaves at the edges of woods. I have never yet found the yellow form among
brown leaves, in copses or woods, nor the red form among the dried yellowish
grass. I think it can be fairly held that the environment settled the lives of the
pronounced colours, varying with the prevailing colour of the spot where the creature
was found, so that the fittest in colour only survived, and that colour was likely to
to be pronounced in the young more and more with every succeeding generation.
Strange to say, but yet not wholly contradictory to this experience, all the
shells exhibited came from one bank. The vegetation was quite mixed, consisting
of dried leaves, grass, short hedge growths, tall thistles and many umbellifera?.
The bank was bordering a main road, and adjacent to a considerable village.