318 



BULLETIN OF THE BUREAU OF FISHERIES 



These data indicate that in the coregonids there is a tremendous difference 

 between the rate of increase in length of the scale and of the body in the early years 

 of life, the scale apparently increasing at a much more rapid rate than the body. 

 In the whitefish this is more clearly shown by graphs (fig. 12). The continuous 

 curve is plotted from the data of the juvenile whitefish and shows, from actual meas- 

 urements, the length relation between body and scale. The broken line shows the 

 form the curve would take if the body-scale ratio of the 41-millimeter specimen were 

 maintained in all the larger fish. 



Fig. 13.— Relation between body and scale length in juvenile whitefish (Coregonus clupea- 

 formis). The continuous curve is plotted from the body length and scale length data of 

 Table 13. The broken line shows the form the curve would take if scale and body main- 

 tained the relation existing at the body length of 41 millimeters 



All the K/ V data together indicate that the herring scale increases in length at a 

 greater rate than the body throughout life — in early life much faster, in later life 

 (third year and thereafter at least throughout the sixth year) only a little faster. 



It may be well to make reference here to Molander's method of studying 

 the relationship of body (i) and scale (F) length (Molander, 1918). This 



investigator compares the y and the -^ft^ ratios for each age group (the marine 



herring studied formed its scales at a body length of 50 milluneters) and 

 assumes that the latter ratios "give the correct picture of the growth 

 relation between fish and scales after the fish has begun to grow 



scales." 



The author finds that whereas the y ratios decline continuously from the 



