3 8 FEMALE BITTERLING I 



that we are dealing with a new hormone or hormonal 

 derivative. 



As the concentration of luteidin during pregnancy is equal 

 to that during the corpus luteum phase in the absence of 

 pregnancy, it is no criterion for the determination of preg- 

 nancy. For this reason the ovipositor test is not suitable for 

 pregnancy diagnosis. 



§ 6. Summary 



We have concluded that, given certain conditions and pre- 

 cautionary measures, the ovipositor test can be used with 

 advantage for certain endocrinological assays. Although more 

 than one mammalian hormone may react positively in a 

 particular test, it may be possible to ascertain from the form 

 of the growth- and/or concentration-curve which is the active 

 hormone. Its advantages are the speed of the reaction (usually 

 within 12 hours), and the fact that the fishes may be used 

 several times in succession. 



The ovipositor test is, in our view, especially suited to the 

 demonstration of the presence of small quantities of pro- 

 gesterone, e.g., in single human corpora lutea. It may also 

 be used to demonstrate the presence of substances not identical 

 with either testosterone or corticosterone, or their derivatives, 

 in the tissue of the testis and the adrenal cortex. 



By means of the ovipositor test the presence of a substance 

 not corresponding to one of the known steroids, and to 

 which we have given the name of luteidin may be demon- 

 strated in human urine. Luteidin is a hydrolysable substance 

 secreted cyclically in non-pregnant women, and in maximum 

 quantity during the corpus luteum phase. During the whole 

 period of pregnancy the secretion of luteidin remains con- 

 stant, and shows the same level as that during the corpus 

 luteum phase. For this reason the ovipositor test is not suitable 

 for pregnancy-diagnosis. 



The ovipositor test is, however, of particular significance 

 for the examination of the sexual hormones of lower ver- 

 tebrates, which are different from mammalian hormones. 



