GROWTH RATE IX PACIFIC SALMON 

 Stream Type. 



11 



There is nothing in this table to indicate that there is any sustained difference 

 in weight ratio in sex, age or tyx>e. It would seem rather that with species in this 

 area, an area where conditions should be much similar for all individuals, although 

 there may be much variation, there is a constant average weight for any length. There 

 is a large enough number of cases where the average is sufficiently exact to show that 

 the weight varies as the cube of the length. Although this is what should be 

 expected it is a satisfaction to have such evidence since it is an assurance that the 

 length of the fish is a safe basis for comparison. This variation can be followed 

 throughout the five species as is shown for the other species in the tables that accom- 

 pany the report on each. 



In comparing the spring salmon collection of 1917 with that of 1916 and that of 

 1915, there seems to be very little difference in the rate of growth in any year of the 

 different year classes. In no case is there much variation in growth for the same year 

 in the different year classes in any collection and the year class that gives the highest 

 average in one collection does not always give the highest average in the other col- 

 lections. Since the collection in each year was a composite one from a wide area, 

 including the entrance to several rivers, it would be too much to expect that there 

 would be exactly the same average even in the same year class. There is no indica- 

 tion that any one year class has had more rapid growth throughout than any other 

 year class. This is true of both the sea and the stream type of fish. 



