144 
REPORTS OF SOCIETIES. 
June. 1891 . 
constituents, and effects on the body. A discussion closed the 
meeting.—May 4th. Mr. J. Madison showed two specimens of 
Planorbis corneas, from Stirchley; the older part of the shell was of 
the normal colour, but the last year’s growth was white. Mr. Madison 
also presented some photographs to the society’s album; they com¬ 
prised views of the “ Devil’s Chimney ” and other rock scenery of the 
Leckhampton district.—May 11th. Special—Geology. Mr. J. W. 
Neville gave an account of the society’s excursion to Linley Caverns, 
Daw End, and showed specimens of the fossils collected there. Mr. J. 
Madison exhibited a specimen of trilobite from the same place; 
Mr. J. Collins, a case of fossils from the Jurassic and Miocene 
formations; Mr. P. T. Deakin, sharks’ teeth from the Red Crag, 
Suffolk, and a series of specimens of Chama squamosa and other shells 
from Barton Cliff; Mr. Linton, three eggs from a blackbird’s nest, 
showing marked variation in colour; Mr. .J. Moore, section of mountain 
limestone with foraminifera in situ. 
OXFORD NATURAL HISTORY SOCIETY.—May 7th. The 
President (Professor A. H. Green) in the chair. Lecture by Mr. H. 
Boswell, M.A., on the ‘‘Life History of a Moss.” The lecturer briefly 
traced the structure and development of mosses, illustrating the 
different stages of their growth by reference to some excellent diagrams. 
He also showed dried specimens of Hypnum stellatum and a few others 
which are now rare in this neighbourhood.—May 21st. Paper by Mr. 
A. Sidgwick, M.A., on the “ Rarity of Insects.” The lecturer dealt 
chiefly with the Hawk Moths, taking as the simplest case of rarity 
those insects which come over and breed in this country. He gave the 
different numbers which appeared each year (from 1846 to 1890), and 
the localities in which they were found, remarking that in the year 
1846, when great numbers of D. Euphorbice were captured, they were 
not to be taken as a proof of permanence, but due to excessive heat. 
He gave three chief causes which contributed to the scarcity, viz.:— 
Failure of food, attacks of parasites, and effects of" climate. 
With regard to the first of these, if the food-plant of a moth confined 
to a special locality were artificially destroyed the insect would 
disappear from that neighbourhood, as in the case of the Large 
Copper, by the draining of the fens. Mr. E. B. Poulton had given an 
interesting example of this, in an account of a very rare Clear-wing 
which fed on docks in the neighbourhood of Dover. The docks were 
all dug up, and it subsisted for some time on sorrel, but became much 
reduced in size, and finally disappeared. Speaking of the effects of 
climate, the lecturer remarked that in the egg stage the insect is com¬ 
paratively safe, because it is firmly fixed to the leaf on which it is to 
feed when hatched. A thunderstorm will, however, sometimes make 
some species rare in a neighbourhood. East winds, frosty nights, 
and too much rain are all injurious. In the chrysalis stage it resists 
frost and flood. An interesting discussion followed, in which the late 
President (Mr. E. B. Poulton) and Colonel Swinhoe took part; after 
which specimens of a few rare moths were exhibited, including one of 
the Clear-wing fed on docks, and ohe of the reduced size, fed on sorrel. 
—Mr. H. M. J. Underhill then read a paper on “ Painting Lantern 
Slides.” He commenced by illustrating on the screen the different 
colours used, and some unfinished slides, showing the actual working 
He then described various ways of smoothing, tinting, making different 
ground colours, &c., together with some other improvements he had 
devised. Some slides of animalcules, in rich shaded blue on a black 
ground, were much admired. 
