382 



SELIG HECHT 



The curves shown in the figures (1 to 5) are all of the form 



y = ax^ 



where y is the weight, x is the length, and a is a factor which 

 varies with the species and with the units used. Table 2 gives 

 the values of a for the six species studied by me and for five other 



zz 



23 



2A 



LE-n&TH -Cns. 



Figure 1 



species. The figures for the plaice (Pleuronectes platessa) repre- 

 sent an average taken from the values given by Johnstone ('12). 

 The values for the European herrings, Clupea sprattus and C. 

 harengus, I calculated from data given by Jenkins ('02), which 

 he used for an entirely different purpose. 



