§ 5 



REACTION TO URINE 



35 



If one compares the curves obtained with the urine, with 

 those obtained with progesterone, androsterone and estrone, 

 then the result is as shown in Fig. 39. Since, out of 27 steroids 



A£. 



z 



w 



18 



22 



26 , 30 

 hours 



Fig. 39. Ovipositor growth-curve obtained with relatively large quantities 



of progesterone, androsterone, luteidin and estrone. Note the typical 



differences in latent time and duration of linear growth. 



examined, none gives a growth-curve resembling those of 

 urine, we are compelled to assume that the ovipositor test 

 has proved the existence of a new hormone or hormonal 

 derivative, which we have provisionally called luteidin 

 (BRETSCHNEIDER and DUYVENE DE WiT, 1937). 



Luteidin secretion in women. Luteidin is secreted both 

 by men and by women; in men however, less than in 

 women. Secretion is not conditional upon pregnancy, for 

 during the menstrual cycle, luteidin is produced. In Fig. 40 



28 days 



Fig. 40. Average luteidin concentration per 3 ml urine of a number of 



normal, non-pregnant women during a cycle converted to a 28 days' 



standard. The maximum falls within the corpus luteum phase. 



