ON THE ARTIFICIAL INDUCTION OF OVIPOSITOR GROWTH IN THE BITTERLING (RHODEUS AMARUS BL.)

In an earlier publication the senior author expressed the view that the ovipositor test can be satisfactorily used for the demonstration of small quantities of progesterone in single human corpora lutea (cf. Bretschneider & Duyvené de Wit, 1947, p. 30) and follicular fluid (cf. Duyvené de Wit, 1941).This view is based on the fact that, compared with many other steroids tested, progesterone has a very high activity in the ovipositor test and shows growth curves that are characterized by a latent period of one hour followed by a period of linear growth of 3½ hours.After this, there is only slight additional growth, cf. Fig. 1. This type of growth curve, however, can only be obtained when1) Present address: University of the O. F. S. at Bloemfontein (South-Africa).2) 46th Communication of the » voor Endocrinologie«.sensitizedand selectedbitterlings are used and the