1887.] 
Prof. Wallace on the Colour of Skins. 
65 
To complete the explanation, we must here take into consideration 
what is known of black-skinned men. Any one who has been in 
India can see that natives, although they drink water freely, do not 
appear to perspire so copiously as Europeans, but this is simply 
because more of the perspiration comes from them in the form of 
vapour, and less is seen to stand like dewdrops on the surface of 
the skin. In the evaporation of the moisture exuding from the 
skin, we have a demand for heat far greater than an ordinary 
observer might imagine ; and by it can be disposed of all the 
surplus heat which the black skin absorbs over and above what it 
gives off by radiation. It is a fact which few realise, that the 
amount of water is small indeed which, by being evaporated, could 
transform into its latent condition all the heat derived from the 
warming influences of the sun in the hottest climates. 
PRIVATE BUSINESS. 
Mr D. S. Sinclair, Dr A. D. Leith Napier, and Mr Alexander 
Galt were balloted for, and declared duly elected Fellows of the 
Society. 
Monday, IWi December 1887. 
Sir DOUGLAS MACLAGAN, M.D., Vice-President, 
in the Chair. 
The following Communications were read : — 
1. On the Height and Volume of the Dry Land, and the 
Depth and Volume of the Ocean. By John Murray, 
Esq., Ph.D. (Published in the Scottish Geographical Maga- 
zine for January 1888. 
2. The Pineal Body {Epiphysis cerebri) in the Brains of the 
Walrus and Seals. By Prof Sir Wm. Turner, M.B., 
LL.D., F.K.S. 
In this paper the author described the pineal body in the walrus 
and in Phoca vitulina and Macrorhinus leoninus, in which animals, 
but more especially in the walrus, it is of larger size than is usual 
in mammalia. In one walrus it measured 30 mm. (IT 8 inch) in 
VOL. XV. 12/6/88 
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