56 
BULLETIN OP THE BUREAU OF FISHERIES 
length at the beginning of the season in 1919, and increased approximately 10 cm. 
between that time and August 8. The greater variability of the fish taken inside is 
not as clearly sho^vn in this group of fish as in many of the others, but a considera- 
tion of the actual deviations of the observed average lengths from the calculated 
lengths (the residuals) shows that even in this instance the fish taken inside are dis- 
tinctly more variable. The average deviation from the trend among the collections 
taken inside is 1 .8 cm., and among the fish taken outside is only 0.9 cm. 
O FS ^'SS ASO 
Fig. 19. — Length of fish in their third year, stream nuclei 
FISH IN THEIR FOURTH TEAR, STREAM NUCLEI 
Figure 20 shows the data for the fish of this age group. As in the last group 
considered, the trends of the fish taken inside and outside are in fair agreement, 
although the agreement is by no means as close as in the 3-year fish. Only 40 indi- 
viduals, scattered through 8 collections, represent this age group among the fish taken 
outside, while there were 489 individuals in 16 collections taken inside. Yet the 
average deviation of the points from the trends is distinctly less in the case of the fish 
taken outside. 
