THE ESSEX FIELD CLUB.
117
Demonstration Lectures.—Two lectures on "Surface Tension and its
relation to Life at the Surface of Water" were given by Mr. Sydney G.
Starling, B.Sc., A.R.C.S., F.Phys. Society, and Head of the Department of
Physics, Municipal Technical Institute, West Ham, and Mr. D. J. Scourfield,
Member of the Council of the Royal Microscopical Society.
The phenomena depending upon Surface-Tension are of supreme importance
in the lives of many aquatic animals, and the lecturers' mode of treatment of the
subject, together with the brilliant and suggestive experiments shown, proved to
be of very great interest.
Mr. Starling dealt with the physics of the problem, and Mr. Scourfield with
its biological aspects. The Syllabus of the lectures was as follows :—
Proof of existence of surface-film of liquids. Properties of such films. Drops
and bubbles ; effect of size upon properties. Resistance of films to penetration.
Capillary effects. Attraction and repulsion of floating objects. Thickness of
films. Ripples.
The so-called surface-film and its significance as a factor in the environment
of aquatic organisms. Examples illustrating the importance of the different
properties of the surface-film in the lives of certain animals and plants, e.g.,
Duckweed and other floating plants, the Aquatic Grasses, Hydra, Entomostraca,
Water Spiders, Water Beetles, Gnat-larvae, Mollusca, etc. Surface-Tension in
relation to proto-plasmic phenomena, e.g., the formation of ectoplasm, amoeboid
motion, etc.
A very cordial vote of thanks was given to the Lecturers on the proposal of
the President.
Remarks on the subjects brought forward were made by Mr. Dalton, Mr. J.
C. Shenstone, Dr. Graham, and others, and Mr. Starling and Mr. Scourfield
replied to special queries which were raised.
The demonstration was highly successful and interesting to all Naturalists
present, and it is to be hoped that similar lectures may be arranged in the
future.
NOTES—ORIGINAL AND SELECTED.
MAMMALIA.
The Marten (Mustela martes) in Epping Forest in 1768.—
All Essex naturalists are familiar with Daniel's statement1 that,
in the closing years of the Eighteenth Century, a tame Marten
was kept in the kitchen of the Bald-faced Stag, at Buckhurst
Hill—a house which still exists. Daniel's record to this effect is
quoted by Dr. Laver in his work on the fauna of Essex.2
Recently, however, Col. H. W. Feilden, of Burwash, Sussex,
has called my attention to the fact that Daniel, in making
the statement in question, was merely quoting from an earlier
1 Rural Sports, i, p. 361 (1801).
2 Mammals, Reptiles, & Fishes of Essex, p. 50 (1898).