of the Fishery Board for Scotland. 



81 



upper tributary unless it has a very considerable volume of water. Once 

 in the main flow the instinct of the spring fish seems to prompt what I 

 have already described as a steady ascent. Early Tay fish do not appear 

 to enter the Earn, the Almond, or the Isla except in rare instances. Spey 

 spring fish do not enter the Fiddoch or the Avon, yet the former is easily 

 the favourite tributary for spawning fish in the autumn. In the case of 

 the Earn there may be room for doubt whether or not the evil influences 

 of the cruives and dam dykes have not in the past destroyed an early 

 run. Yet this river might almost be regarded as a distinct river from the 

 Tay, just as the Beauly is distinct from the Ness, though both have a 

 common estuary. The Earn flows out of a loch 6J miles long, the surface 

 of which is 306 feet above sea-level, i.e. 250 feet lower than the surface 

 of Loch Tay. It then has a course of 46 miles to the estuary of the Tay 

 above Newburgh. The Earn itself is tidal for about four miles. In the 

 British Assoc. Report for 1891 I find, in a paper by Dr. H. R. Mill, 

 monthly means given, for the year 1888, for the Earn at Bridge of Earn, 

 for the Tay at Perth, and for the river Almond. From these it would 

 appear that during the early months of the year the Earn has greater 

 fluctuations than the Tay. It is in this year 1*4 degrees higher in 

 temperature in January, three degrees higher in May, but slightly lower 

 in February, March, and April. The presence of these higher means is 

 striking, but perhaps misleading for the reason to be stated presently. 

 The Almond, on the other hand — the first tributary above the junction 

 of the Tay and Earn — is lower in temperature than either of the two 

 other rivers, and this for each month mentioned. The monthly means 

 are as follows : — 



1888. 



Earn. 



Tay. 



Almond. 



Jan. 



39-2 



37-8 



36-7 



Feb. 



35-7 



37-5 



34-4 



Mar. 



37-1 



37-4 



34-7 



April 



42-8 



43-6' 



37-3 



May 



49-9 



46-9 





In accordance with the deductions already made from the records of the 

 Garry and Lyon, we are not surprised at the Almond being a late 

 tributary. With regard to the Earn, however, I am of opinion that the 

 readings given above must be somewhat misleading, since they were taken 

 at Bridge of Earn, which is within the tidal area of the river, and may 

 therefore at times have been influenced by tidal water forced upwards 

 from the estuary, where the influence of the ?.arger river Tay must 

 predominate. I should suppose, therefore, that these Earn readings may 

 approximate too closely to the Tay readings. At the same time, if this is 

 the case, the question may with fairness be asked, Why do the Earn runs 

 of fish not approximate more closely to the Tay runs if Tay water is 

 found some distance up the Earn 1 To this in the present impoverished, 

 though we hope improving, state of the river's fishings it is impossible to 



