Growth and Development of the Salmonidce. 163 



their shells. The parrs which remain in the 

 river for a second year grow very little during 

 that time, and do not assume the smolt 

 dress until near the time for migrating to the 

 sea in the following spring. It is believed 

 that the smolts which commence their journey 

 to the sea in May, return to the rivers to 

 spawn in four or five months after reaching 

 the sea, having attained a weight of 4 or 

 5 lbs. ; while their brothers and sisters of 

 the same age remain in the river, as parrs 

 of two or three ounces in weight. The young 

 salmon, on its first return from the sea, is 

 called a " grilse ; " after it has deposited its 

 spawn, it falls off in condition, and is then 

 unfit for the table, and loses greatly in weight. 

 It returns to the sea, and on its next ascent, 

 in the following season, is called a " salmon," 

 and will then weigh 10 or 12 lbs. It is be- 

 lieved that the transformations and habits of 

 the Salmo trutta and Salmo eriox are similar 

 to those of the true salmon, but these fish do 

 not attain to the same size. 



The Salmo salar, when detained in fresh 

 water, has its growth greatly checked. In 

 Scotland, some salmon fry, three to four inches 



