1904-5.] Study of the Lakes of Scotland and Denmark. 401 
A Comparative Study of the Lakes of Scotland and 
Denmark. By Dr C. Wesenberg-Lund, of the Danish 
Fresh- water Biological Station, Frederiksdal, near K. Lyngby, 
Denmark. Communicated by Sir John Murray, K.C.B., 
F.R.S. ( From the Danish Fresh-water Biological Laboratory , 
Frederiksdal.) (With Two Plates.) 
(MS. received January 13, 1905. Read January 23, 1905.) 
Introduction. 
In June 1904 I received an invitation from Sir John Murray to 
visit Scotland and spend three or four weeks in exploring the 
Scottish lakes, in order to make a comparison between them and 
the Danish lakes : he was of opinion that such a comparison of 
the lakes of a highland and a lowland country, which had hitherto 
not been attempted, would lead to some interesting results. The 
admirable bathymetrical and physical explorations carried on by 
Sir John Murray in Scotland, and more especially in Loch Ness, 
being far advanced, the question as to the scope of the biological 
observations called for consideration ; so he desired me to indicate, 
from the impressions derived during my visit, my views as to the 
most useful lines of investigation that might be taken up with 
reference to the biology of the Scottish lakes. I was much 
interested in the task imposed upon me, and at the same time 
gratified at the prospect of assisting in the design of the biological 
explorations in the lakes of a foreign country ; and as it was of the 
greatest significance to me to learn the nature of alpine lakes, I 
immediately accepted the invitation. I spent three weeks in 
Scotland, — the first two at Fort Augustus, on Loch Ness, and the 
third in Edinburgh. From Fort Augustus I explored the lakes of 
the Caledonian Canal, and thus became acquainted with alpine 
lakes ; from Edinburgh I explored a few lowland lakes, especially 
Loch Leven. The steamer Mermaid , belonging to the Marine 
Biological Station at Millport, fully equipped for deep-sea work, 
PROC. ROY. SOC. EDIN. — VOL. XXV. 26 
