of the Fishery Board for Scotland. 
191 
The warmest water which I found was at West Loch Tarbert, where, in 
Messrs Hay & Co.'s pond, the temperature was 16°'75 C. at 5 p.m. on 
11th July. At Linne Mhuirich on the following day the temperature near 
the shore, 2 feet deep, was 14° '7 C, and in the middle, opposite Captain 
Campbell's house, at a depth of 3 fathoms the surface was 14° "4 C, and 
the bottom, 14° '6 C. The highest temperatures were exhibited by West 
Loch Tarbert, Loch Ryan, Loch Swen, and Loch Tarbert (Jura), but in 
all this it must be borne in mind that the temperatures were taken on 
different dates. AVhen at Loch Ryan and West Loch Tarbert 1 initiated 
arrangements for the temperatures being taken daily at fixed positions, 
and these will prove valuable in showing the temperatures of these two 
oyster-beds. 
3. Biological Characters. 
In dealing with biological conditions it may be as well to distinguish 
those lochs in which I obtained living oysters from thqse in which only 
the shells of dead oysters could be obtained. The lochs already mentioned, 
with the exception of Lochs Scridain, Moidart, Aylort, and Harport, fur- 
nished livingi' oysters ; but no doubt with a greater amount of time at my 
disposal it might have been possible even in these, particularly Lochs 
Scridain and Harport, to find some living example of former oyster-beds. 
From Loch Dunvegan Mr Johnston of Cumberland kindly forwarded to 
me examples of rock oysters. At this point it may be noticed that most 
of our Highland lochs can furnish 'rock' oysters, i.e.^ oysters taken from 
the rocks on the foreshores — but as these are so few in number, and may 
exist where it would be impracticable to form oyster-beds, in any investi- 
gation they can be left out of account. In Lochs Moidart and Aylort, in 
each of which I dredged several times, it was almost impossible for the 
dredge to go more than a yard or two without becoming filled with the 
enormous prolific growth of Ectocarpus and other sea-weeds. These two 
lochs may come under the description of very ' dirty ' lochs, where, before 
shell-fish culture of any kind is essayed, it would be necessary to clean 
the bottom. To do this, tons upon tons of sea-weed would have to be 
removed. There are many long narrow inlets in the Outer Hebrides 
where there is the same vigorous growth of sea-weed covering the bottom. 
In the autumn months of the year the bottom is entirely hidden by this 
growth, and it is only on the continuation of wintry weather that the 
bottom becomes comparatively freed from this covering. Of course it may 
be answered that for oyster culture it is necessary to keep the beds clean. 
This is quite true ; but the expense of keeping such bottoms as those of 
Lochs Moidart and Aylort free from this deleterious growth is much 
greater than is the case in lochs which are naturally cleaner. Notwith- 
standing, the occurrence of Zostera marina shows that the bottom is 
such that it would not be difhcult to keep it clean when the algie 
were completely removed. A not uncommon fallacy prevails in this 
country that oyster culture is so comparatively simple that after oysters 
are planted the beds can be left to take care of themselves. This is on a 
parallel with land cultivation, where, stating a like fallacy, it might be 
said potatoes and turnips only require to be placed in the ground and left 
to take care of themselves, in order that they may yiehl an abundant and 
profitable crop, not in one year only, but during successive years. Scien- 
tific oyster culture, like scientific agriculture, demands continuous care 
and attenti(m. 
It will be convenient to treat the inlets visited under two heads — viz., 
(1) Lochs where oyster culture has been attemi)ted and is presently being 
carried on ; and (2) lochs where no culture has be»;n tried. 
