THE SALMON AND WATER TEMPERATURE 135 
into the river Oich, out of the Oich into Loch Oich, 
and out of Loch Oich into the famous river Garry, 
which forms the head waters of the Ness system. 
The Garry is the spring fishing river of this district. 
On the west coast we have an analogous condition 
appearing in the Awe district. arly fish pass 
through the river Awe into Loch Awe, and are 
cheeked in this ascent only after they have entered 
the river Orchy above the loch. The Garry and the 
Orchy are rivers of considerable size, although each 
is some distance from the sea. In each there is a 
fall, beyond which’ fish do not commonly pass till 
about May. Now, why do Tay fish remain in the 
lower river and loch during the spring months, and 
Ness and Awe fish ascend to the upper feeders of 
their districts ? 
In order to ascertain the thermal conditions of the 
river systems referred to, I arranged for the taking 
of morning and evening maximum and minimum 
readings from thermometers kept constantly im- 
mersed in the Ness and the Garry and in the Awe 
and the Orchy. At the same time temperatures 
were taken in the Tay and in one or two smaller 
river systems. The Garry rod-fishing opens early 
in February, and at that time each year the river is 
well stocked, although in exceptionally cold springs 
there may be more fish in Loch Oich than in the Garry. 
In the Awe, fish do not usually ascend till March, 
and are not expected in any numbers in the Orchy 
till April. It is highly probable that with a fuller 
stock of fish in the district more earlier fish would 
appear. The readings procured from these districts 
