32 lVansactio7is. 



in the sea for the longer period — say from May of one year to 

 July of the following year— did not seem to attain a very much 

 greater size than those which returned in the shorter period. 

 The same peculiarity was noticed in the case of tame trouts kept in 

 ponds. Some grow much more rapidly than others. It has been 

 found that parr become smolts and go to sea, some of them the 

 first year ; the great majority, the second year ; and some not 

 till the third year. This too, was exactly the case among domes- 

 ticated trout. It was found necessary at the end of the year to 

 take the tish out of the pond and sort them. If tJris were not 

 done, the big ones would eat the little ones, and at the end of 

 two or three years their size would be altogether disproportioned. 

 some weighing only two or three ounces, others as many pounds, 

 I have known cases of domesticated trout reaching 4 lbs. in two 

 years, whereas usually it takes three years for a trout to reach 

 1 lb., even when domesticated. A smolt let ofl' in May at Stor- 

 montfield returned in July, weighing 3 lbs. On the other hand, 

 a smolt which the Duke of Roxburgh let off on 14th May did not 

 return until July of the next year, and it had then attained a 

 weight of only Qh lbs., having in fourteen months just doubled 

 the weight gained by the other fish in three months. These, and 

 many other observations, proved that fish spending a long time 

 in the sea did not continue to grow at the same rate as in the first 

 few months. There was very little doubt that food supply was 

 the great incentive which drove salmon to the sea. They did 

 feed, and feed voraciously, in our rivers at times. But sometimes 

 they took little food — when spawning, for example; when the 

 temperature was very low, and when on migration. It was 

 quite possible, for these reasons, to get plenty of salmon with 

 nothing in their stomachs ; and as their digestion was very 

 rapid, even after a good meal, no trace of it might be fonnd 

 a few hours afterwards. The idea seemed to exist in many 

 minds that the huge l)odies of the salmon were developed by a 

 very indefinite something which the tish managed somehow or 

 other to obtain by a process which they called suction ; and this, 

 as a recent writer very aptly remarked, pointed to something like 

 microscopic supplies. But there was no doubt the food of the 

 salmon in the sea consisted largely of herrings, young and old, 

 sand eels, Crustacea, &c. They followed the young herring shoals 

 closely. In many cases they had been found goi'ged with young 

 herrings ; and I have a report from the Highlands stating that a 



