180 ANOMALIES IN SALMON GROWTH. [CHAP. v. 



grow with considerable rapidity, especially if it is to be a 

 twelvemonth's smolt, and this is very speedily seen at such a 

 good point of observation as the Stormontfield ponds. The 

 smallest of the specimens given in the preceding page represents 

 a parr at the age of two months ; the next in size shows the 

 same fish two months older ; and the remaining fish is six 

 months old. The young fish continue to grow for a little 

 longer than two years before the whole number make the 

 change from parr to smolt and seek the salt water. Half of 

 the quantity of any one hatching, however, begin to change at 

 a little over twelve months from the date of their coming to 

 life ; and thus there is the extraordinary anomaly, as I shall 

 by and by show, of fish of the same hatching being at one 

 and the same time parr of half an ounce in weight and 

 grilse weighing four pounds. The smolts of the first year 

 return from the sea whilst their brothers and sisters are 

 timidly disporting in the breeding shallows of the upper 

 streams, having no desire for change, and totally unable to 

 endure the salt water, which would at once kill them. The 

 sea-feeding must be favourable, and the condition of the fish 

 well suited to the salt water, to ensure such rapid growth a 

 rapidity which every visit of the fish to the ocean serves but 

 to confirm. Various fish, while in the grilse stage, have been 

 marked to prove this ; and at every migration they returned 

 to their breeding stream with added weight and improved 

 health. What the salmon feeds upon while in the salt 

 water is not well known, as the digestion of that fish is so 

 rapid as to prevent the discovery of food in their stomachs 

 when they are captured and opened. Guesses have been 

 made, and it is likely that these approximate to the truth ; 

 but the old story of the rapid voyage of the salmon to the 

 North Pole and back again turns out, like the theory upon 

 which was built up the herring-migration romance, to be a 

 mere myth. 



