374 



BULLETIN OF THE BUREAU OF FISHERIES 



represent the average growth rate for the whole period covered by the years 1915 

 (1914) to 1924, inclusive. The cxirve plotted from the grand averages of Table 43 

 shows gi-aphically the average growth of the lake herring during the last 10 years. 



m 





JZT 



m 



Ml 



Fig. 39. — Total length and increment in length attained by Saginaw Bay herring at the end 



of each year of life. A, curves based on grand averages of total lengths: , curve 



plotted from the grand averages obtained by combining the actual lengths of all fish belonging 



to the same age group. (See Table 34.) . , curve plotted from the grand averages 



obtained by combining the computed lengths of corresponding years of life of all the available 



herring of all age groups. (See Table 26.) , curve plotted from the grand 



averages obtained by combining for corresponding years of life the actual and computed 

 lengths of all available herring of all age groups. (See Table 43.) B, curves based on grand 



averages of annual increments: , curve plotted from grand averages based on actual 



measurements of fish. (See Table 34.) — . — , curve plotted from grand averages based 



on computed values. (See Table 26.) , curve plotted from grand averages 



based on actual and computed values. (See Table 43.) 



Table 43. — Total average length attained by each year class of Saginaw Bay herring at end of each year 

 of life when uncorrected computed averages are combined ivith actual averages for corresponding 

 years of life. {Tables 26 and 34 combined.) ' 



> Number of specimens employed is given in parentheses. 



" Based on direct measurement of fish. 



" Actual and calculated values combined; all unmarked averages are calculated from scales. 



