370
THE ESSEX FIELD CLUB,
was quite normal for the district and time of year and calls for no special
remark. In the Higham Park lake, specimens of Hydra fusca and other forms
were obtained.
Tea was taken at the Royal Forest Hotel, and afterwards an Ordinary
Meeting (the 179th) was held in the large room in the hotel, the President
in the chair.
The Secretary exhibited a specimen of Crepidula fornicata, L., which had
been presented to the Museum by Dr. Laver. The mollusc had been found
living attached, limpet-like, to a stone dredged up from the River Colne.
The animal contained a large quantity of ova. The mollusc was a
comparatively recent importation from North America, probably brought
over attached to oysters. It was now evidently breeding both in the Colne
and the Crouch rivers.
Mr. Walter Crouch exhibited a series of specimens of Crepidula from
Essex waters, ranging from quite small individuals to those of almost mature
size, and made some interesting remarks on the same and on Dr. Laver's
specimen, which are summarised at page 353 ante.
The President said that this was an exceedingly interesting instance of
the introduction of a new species which was apparently thriving and bade
fair to become naturalized. Professor Meldola remarked that it would be
a valuable observation to ascertain whether any changes of form or colour
resulted from the change of environment.
The Secretary read a paper by Mr Edward Lovett on the use of wooden
fish-hooks made from thorns on the Essex coast, and exhibited drawings of
the hooks, and some models made by Mr. H. A. Cole on the same plan.
Mr. Lovett's paper was printed in the last part of the E.N. ante pp. 300—5.
Mr. Cole said that his attention had been directed to this subject by
seeing last year in the Economic Botanical Museum at Kew a card with
some white or black-thorn thorns on it, labelled "Thorns used as fish-hooks
on the coast of Essex." After some enquiry he found that Mr. Lovett had
also noticed this singular custom or survival, and the paper just read was the
result of correspondence with him.
Mr. Crouch alluded to the use of bone fish-hooks by the Eskimo and
other tribes.
Thanks were voted to Mr, Lovett for his interesting paper.
A Lecture was then delivered by Dr. H. C. Sorby, F.R.S., on "The
Preparation of Marine Animals as Transparent Lantern-slides; illustrated by
characteristic forms from the Essex Coast."
The subject was one which had occupied Dr. Sorby's attention for some
time, during his cruises off the coast in his yacht, "Glimpse." The
preparation of mariae animals as lantern-slides, so as to show not only their
true general form, but also much of their internal structure, is as much a
chemical as a biological problem, and different animals require very different
treatment. A series of slides was exhibited by the lantern, prepared from
animals taken off the coast of Essex, and the adjoining parts of Suffolk, so
as to illustrate the processes, the gradual development of the methods, the
great advance recently mads, and the advantages of special modes of
treatment. A collection of photographs of similar examples was also shown.
[An abstract of the lecture, written by Dr. Sorby himself, is printed in the
present part, ante pp. 346-50.]