Figure 1. — Reactions on typical double-diffusion slide demonstrating tests 

 for presence of HM antigen in kidney-tissue fluids of female English sole. 

 Magnification 5X. 



Figure 2. — Demonstration of single-diffusion technique to estimate relative concen- 

 trations of HM antigen. End point is seen at 1/160 dilution. Magnification 2.5X. 



SERUM FACTOR IN MATURITY 



49 



