§ 7 THE LUTEIDIN PROBLEM 39 



We doubt whether it is possible to produce reactions in 

 mammals by the administration of sexual hormones produced 

 by fishes (oviductin and copulin, (vide p. 56 and 131). In 

 fishes, however, the ovipositor test is adequate, and may there- 

 fore be regarded provisionally as an appropriate method for 

 both qualitative and quantitative hormonal analyses in non- 

 mammalian vertebrates. 



§ 7. THE LUTEIDIN PROBLEM 



Luteidin is the name given by DUYVENE DE WiT to a 

 hitherto unknown component of urine, both of men and 

 women, which as yet can be identified only by a peculiar 

 growth-curve in the ovipositor test, which growth-curve 

 cannot be produced by any of the known active hormones 

 generally present in urine, either separately or unitedly, the 

 form of this growth-curve being determined by the following 

 data:— 



a. the latent period is 5 >^ hours; 



b. after this, very marked and rapid growth sets in, 



c. which growth reaches its maximum after about 12 

 hours, and may — all according to the sensitivity of 

 the fishes — amount to as much as 7 A.U. per 3 ml 

 of urine 22° C. 



Maximal growth may even be obtained sometimes with 

 the addition of i ml urine to 750 ml aquarium water. 



In the course of a systematic investigation, DUYVENE DE 

 Wit has shown that a growth-curve of this sort differs 

 essentially from that produced by 27 different steroids, 

 amongst which were estrogenic and androgenic substances: 

 progesterone, pregnanediol and cortical-steroids. In the case 

 of pregnanes and androstanes, the latent period is much 

 shorter, whilst in the case of estrogenic steroids — again the 

 only group of substances with the same latency time of 5 ^ 

 hours — the maximum of growth is lower and much more 

 protracted. The united participation in the total growth, on 

 the part of steroids normally present in urine is only small; in 



