FEMALE BITTERLING 



% 



c. Desoxycotticostetone-acetate. With concentrations of ^ , 

 I, lYz, 2, 2.y2, 7y2, 17^2, 50 and 150 7 per 750 ml water 

 the following growth-curves were obtained (Fig. 19). The 

 characteristics of these curves are:— 

 ^ Latent period, i hour. Linear growth ends after 4 hours. 



It appears from the above that desoxycorticosterone is 80 

 times, and desoxycorticosterone-acetate 200 times as active as 

 corticosterone. 



It is interesting that corticosterone A 4,5 pregnene, 11, 

 2i-diole-3,20-dione) is 60 times less active than proges- 

 terone, while desoxycorticosterone (21-oxy-progesterone) is 

 1,3 times as active as progesterone. Perhaps the activity of a 

 pregnene is weakened by an OH-group, attached to Cn, buc 

 intensified by an OH-group, attached to C21. 



C. The reaction to androstanes. 



a. A 4,^-andtostenedione-^,iy. With concentrations of 

 Ya,, Yi, I and i^ mg per 750 ml water the following 

 growth-curves were obtained (Fig. 20). The characteristics 

 of these curves are:— 



A.U. 



Fig. 20. Ovipositor growth curves after administration of 

 A 4,5 androstenodione. 



