Sexual Endocrinology of Non-Mammalian Vertebrates

Abstract

Chapter 1 records the effects of various substances added to the water of the aquarium on the growth of the ovipositor tube of a small fish, the bitterling. Various substances give characteristic curves when onset and rate of growth are plotted against time, and the test can be made quantitative. Steroid hormones have especially low thresholds; 4 to 6 micrograms of progesterone, for example, produce measurable growth in less than five hours. Extracts of human corpora lutea gave curves resembling those of pure progesterone. Unfortunately, the only basis for seriating them was the clinical history. Four which were removed during menstruation gave as high values as the average of all cases in which the results were positive. A pair of ovaries from a full term infant showed as much progesterone per gram of tissue by this test as any of the corpora lutea. The test cannot be used for the