Testicular Changes Resembling Early Stages in the Development of Interstitial Cell Tumors in Mice of the A Strain after Long-Continued Injections of Pregnant Mare Serum^*

This study was aided by grants from The Jane Coffin Childs Memorial Fund for Medical Research; the National Research Council, Committee for Research in Problems of Sex; The Anna Fuller Fund: The International Cancer Research Foundation; and the Fluid Research Fund of Yale University School of Medicine. The pregnant mare serum (gonadin) was supplied by Cutter Laboratories, through the courtesy of Drs. D. H. Wonder and C. Parham.