12 
of Wiltshire, that the rate of formation of stalagmite was much influenced 
by currents of air. 
Mr. W. W. Stoddart, F.G.S., referred to Mr. Pengelly's paper on 
such caves in Cornwall, and mentioned the discovery of a copper pin under 
nine inches of stalagmite. He also spoke of the great influence of the 
tide in sorting and arranging cave deposits. 
After the conclusion of the discussion, Mr. C. O. Groome Napier, 
F.G.S., exhibited a specimen of the Spur-winged Plover, a bird common 
in Egypt, which was known to enter the crocodile's mouth, for the pur- 
pose, probably, of removing leeches. It had a remarkably sharp horny 
spur on the wing, the use of which was not known. It was very cunning, 
unlike the Dottrell, to which it was allied, and eggs of which were exhi- 
bited. This bird, as was well-known, was very foolish, and rarely bred in 
Britain. 
Mr. Pease and Mr. Swayne questioned the existence of leeches, but 
believed the plover acted as a kind of living toothpick to the crocodile. 
Mr. Napier also exhibited a cocoon of the Tarantula spider, from 
Tobago, which had contained 100 eggs, about the size of rape-seed. 
MEETINGS OF SECTIONS. 
ZOOLOGICAL SECTION. 
February 8. — Dr. H. Fripp, President of the section, in the 
chair. 
Mr. H. K. Jordan, F.G.S., exhibited a series of Helix Virgata, a new 
variety, of a dusky colour, for which he proposed the name H, Virgata, 
var. tenebrosa. Also, a series of Helix rufescens, var. depressa, a rare 
shell, found at Paignton, South Devon, and lately on Durdham-down. 
The President then showed and explained a large number of very 
beautiful microscopic preparations, illustrating anatomically the minute 
structure of the eyes of fishes. The crystalline lens, choroid coat, and 
pigment cells, the iris and ciliary processes, were thus minutely examined, 
and especial attention was drawn to the peculiar arrangement of blood 
vessels in what was commonly called the choroid gland, the function of 
which Dr. Fripp had endeavoured to explain in his recent paper read at 
the general meeting of the Society in January. The separation of the 
arterial trunk, soon after entering the eye, into an immense number of 
exceedingly minute capillaries running parallel to each other and most 
closely packed, was well seen, and the subsequent reunion of these into a 
so-called venous, but, strictly speaking, arterial sinus, whence the blood 
was distributed to nourish the tissues of the eye, was clearly demonstrated. 
