of the Fisher )/ Board for Scotland. 



same age. A few of the larger ones had assumed the smolt dress, but 

 the most of them were still parr. Some specimens were retained for 

 examination, and particulars of their scales are given in the above 

 Table. The sex was ascertained with the aid of a microscope, but, of 

 course, the organs were in a rudimentary state, though the ova in all 

 the females, except the smallest, was quite distinct. 



The scales of the two smaller specimens were protected by thick 

 membrane, but on all the others it was more attenuated. The number 

 and arrangement of the ridges on the scales of these Stormontfield fish is 

 not quite the same as in river parr of similar age, and this is probably 

 a result of hand-feeding, but we do not find as large a growth as in the 

 Tugnet specimens (referred to in the Twenty-third Report), where perhaps 

 the dietary was more liberal and the water warmer. On the day that the 

 Stormontfield ponds were run off they were covered by a thin coating 

 of ice, and the temperature of the water was about 33°, although it 

 comes from the Tay, which at the same time was 3 Q warmer ; the 

 explanation probably being that the mill lade from which the water is 

 taken runs for a long distance between wooded banks and partially 

 under a cliff. 



There were no younger parr in the ponds when I visited them in 

 March 1906, but a few weeks after the liberation of the two-year-olds 

 the water was restocked on 27th April and 2nd May with 70,000 fry, 

 which were about 64 days old when transferred from Dupplin Hatchery, 

 so that in March 1907 they were practically a year old. With the 

 sanction of the Tay District Board, I tried in that month to secure a 

 few of these young fish, but they had not wakened out of their winter 

 lethargy, and I only managed to obtain one specimen (9*4 cm., -| oz.), 

 which may not be representative. A photograph of a scale is included 

 in Plate I. 



There has always been much doubt expressed as to the utility 

 of hatcheries, and no direct satisfactory proof has been brought forward 

 that they are worth the money expended on them. All that can be 

 said is that they do no harm and may do good. If we could show that 

 some of the salmon which return from the sea are hatchery fish, then 

 there would be something to go upon ; but till recently there has been 

 no way of identifying them except by the very unreliable method of fin 

 mutilation. Now, however, this difficulty has been overcome and 

 smolts marked with a wire have been recaptured both as grilse and 

 salmon, and are afterwards referred to. If the same method of marking 

 with a distinctive wire were adopted in the case of artificially -reared 

 smolts we would be able to identify them in after years, and even to 

 compare the percentage of recaptures with the information derived 

 from marking river smolts, and thus would be a step nearer the solution 

 of the problem. 



In the same way valuable results might ensue from using special 

 wires to mark the parr in the main river and in the tributaries, with 

 the idea of finding out if the early environment of the fish has any 

 influence on its growth and habits in after life. For instance, in the 

 Tay there are two distinct classes of spring fish — one of four-year-old 

 salmon weighing about 10 lbs., and the other chiefly composed of five- 

 year-old fish of about double this weight. The greater number of both 

 classes, in an ordinary season, appear to be fish returning to fresh water 

 for the first time, and it would be interesting to find out if the reason 

 for this difference in the age of return can be traced to the domicile of 

 origin, or is dependent on unknown causes in the ocean. 



