14 



FEMALE BITTERLING 



Latent period, i Yz hours. After this the curve runs hori- 

 zontally. 



f. A 5,6 pregnenol, ^-one-20. With concentrations of 

 50, 75, 100 and 250 y per 750 ml water the following 

 growth-curves were obtained (Fig. 13). The characteristics of 

 these curves are:— 



Latent period, 2>^ hours. Linear growth ends after 7>4 

 hours. 



pregnanol- 20 -one -3 



2 4 6 8 ^ JO 



hours 



Fig. 15. Ovipositor growth curves after administration of 



pregnanol- 2 o-one- 3. 



g. Ptegnanedione, ^-20. With concentrations of 25, 50, 

 75, 100 and 250 y per 750 ml water the following growth- 

 curves were obtained (Fig. 14). The characteristics of these 

 curves are:— 



Latent period, i Yz hours. Linear growth ended after 5 

 hours. 



h. 'Pregnanol, zo-one-^. With concentrations of 150, 

 300, 500 and 750 y per 750 ml water the following growth- 

 curves were obtained (Fig. 15). The characteristics of these 

 curves are:— 



Latent period, i^ hours. Linear growth ends after 6^ 

 hours. 



r. Pregnanediol, j-20. Only with the high concentra- 

 tion of 2000 y per 750 ml water could a distinct reaction be 

 obtained (Fig. 16). The growth-curve is probably of the type 



