THE SALMON 45 



fresh water as a parr, and a few rings rather closer 

 together than the rest at the beginning of the 

 third summer's growth were probably formed in 

 fresh water in April and May ; then the smolt 

 migrated to the sea and fed there for two summers 

 and two winters, and in the following spring entered 

 fresh water, where it stayed for a year, spawning 

 in the autumn and getting back to the sea in the 

 spring ; then after a year in the sea it again entered 

 fresh water and was caught, being then six years 

 old. The scale shows the spawning-mark very 

 clearly, and it should be particularly noticed that, 

 although the fourth winter's growth has persisted 

 near the anterior end, it has been completely 

 obliterated at the sides ; this is due to the great 

 shrinkage in girth after spawning, when the upper 

 and lower edges of the scales get frayed and worn ; 

 during the fifth summer and winter of this fish's 

 life not only did no scale growth take place, but 

 that of the previous winter in great part disappeared. 

 Having given some account of the normal life of 

 the Salmon, and of the ways in which this has been 

 ascertained, we may consider certain abnormalities. 

 The earliest age at which Salmon usually become 

 sexually mature is three and a half years, when they 

 have been to the sea and have run up as grilse, but 

 it sometimes happens that male parr, only 6 to 8 

 inches long, are full of milt, and it has been proved 

 experimentally that they are perfectly fertile ; 

 female parr with ripe eggs are unknown, but Day 

 mentions that of some smolts in the Howietown 

 ponds, which were prevented from going to the sea, 

 one developed ripe eggs in the autumn of the same 

 season, when less than i lb. in weight. 



