582 THE OCEAN WORLD. 



weight, and grilse weighing four pounds. The smolts of the first 

 year return from the sea, while their brothers and sisters are timidly 

 disporting in the breeding shallows of the upper streams." A late 

 sea -going smolt explains the anomaly of a spring salmon. 



It thus appears that, in this first stage, the young salmon (Fig. 380) 

 is called 3. parr; during the second it is a smolt, namely a parr plus 

 a jacket of silvery scales. While they continue in the state of parr 

 they lead a secluded life, totally unable to endure salt water, which 

 would kill them. When they have become smolts the fish betake 

 themselves in troops to the sea. The sea- feeding being favourable, 

 and the fish strong enough for the salt water, a rapid growth is the 

 consequence. After that they disappear, spreading themselves over 

 the wide world of the ocean. At the end of two months of a life 

 mysterious and so far unknown, these fishes reappear in the rivers, 

 returning to their native pools ; but how changed! Quantum 7mitati ! 

 The smolt, which has lived in the rivers two or three years, and only 

 attained the length of six or eight inches, returns at the end of two 

 months' sojourn in the sea, weighing three to four pounds, and, after 

 six months', ten or twelve pounds. It is now a grilse. 



After depositing their eggs the grilse remain some time in the 

 fresh water, when they again go to the sea. This second sojourn, of 

 about two months, is sufficient to send it back weighing from six to 

 twelve pounds. It is now an adult salmon. Each new visit to the 

 sea brings the salmon back increased in size in proportion to the 

 duration of the voyage. In the month of March, 1845, the Duke of 

 Athole took a salmon in the Tay after it had deposited its eggs ; he 

 marked it by attaching a metal label to it. It weighed ten pounds. 

 The same individual, with its metal label, was again fished up after 

 five weeks and three days' absence. It now weighed twenty-one 

 pounds, having in the meantime travelled forty miles down the 

 river to the sea. This fish must, however, have made a long 

 sea run during these thirty-eight days and its seeking up the river 

 again. 



In most circumstances, according to Mr. Blanchard, to whom we 

 are indebted for much information relative to the development and 

 migration of these fishes, salmon of various ages, which have never- 

 theless sojourned in the sea as grilse, adult salmon, and others inter- 

 mediate between them, whose first sojourn at sea has extended to 

 eight or ten months, ascend the rivers together in an order no less 

 varied, the older individuals heading the column, the youngest bring- 

 ing up the rear. 



When the period for depositing their eggs approaches, a male and 



