Fig. 1.  Vitellogenin titer in cod serum assigned to maturity classes by visual inspection of the gonads. Vg was determined by quantitative immunoelectrophoresis.   The Vg titer is measured as a percentage of estradiol induced level in the serum of cod that were maintained at the NMF Aquarium at Woods Hole.   This relative scale will be transformed into absolute units when the Vg has been purified.   (a static version of this figure is available as qiep1-6b.gif)