in physiologiciil nctioii by iiitrodiicing iii the A11 2position, n doiiblc bond in thc iiinlc liorinoiic niidrostnndioue : 0 0 t\iidrostnndionc A ,-r\iidrostciitlioiic d ? This trnrisitioii is cspcci~illy rcmnrk:iblc ~rlicii thc iniportnncc of A ~v ~-niidrostendioiic (SV) is rcc:illetl. It is n liiglily ncbivc iiinlc horiiioiic iiiiitcrinl. 2. 11 2-Aiidrostendioiie cuiiscs complctc acstrus in n cnstriitctl fcinnle iiioiise wlicn injcctcd in 4 x 600 y ; on tlic otlicr hiiiid, 4 nig. give iio growth of the c:ipoii comb. 111 this cxwnple, tlic dill'crciicc betwccii n iiinlc niitl fcmiilc eubstaiice is iiierely in tlic position of t,hc tloul~lc hoiid in ring I. It is to bc cspected tlint CoiitinIiiitioIi of ttliis rcserircli will revcal fiirthcr nstoiiisliiiig csiiiiiplcs of LL siiiiilnr kind. It reinailis to bc sceii liow fnr tliesc fiiidiiigs arc of iiictnbolic import,nncc. In view of the findings nlrendy dcscrilwd t,lic possibility must bc coiisidcrcd of n inciterin1 comhiiiiiig tlic folliculiir aiid testiculnr horinoue activities, ix., protluciiig fciniilc activity in tlic cnstratctl fciiiillc ~iiiiuiiil niid inalc iict,ivity in tlic cnstmted iiinlc iiiiiiiiiil. Tlic first siibstniicc possessiiig biscsrinl propert,ics was forind Iiist year. It causcd with 1 x 1.25 nig. or 4 x 100 y, full ccstriis in n cnstriitcd iiiousc : with 2 x 1.3 ing., nbout i l 20% growtli of tlic cnpoii coiiib. It stiiniilotcd dcvclopmcut of tlic iiiiilc gciiital triict ns wcll :is tlic uterus. Tlic discorcry of IL single siibstiiiicc prodiiciug thc cffcct of two difl'crciit lioriiioiics, in close chciiiicnl rcliitionsliip witdi the iinturnl scs Iioriiioiics, aiitl tlic possil)ility of stich n compound occiirrhg i n thc orgniiisni, st.iiiiiiliitcs rcscnrcli in iniiiiy dircotioiia.
0 hll! ii 011 a1c I Pcli yd ro-n l i d rost crcuic Aiitl rostciicl iol d d ?
XOW tlint tlic cliciiiicul constitiit ions of tlie scs Iior-i1ioiics iirc cstnblislictl t i i d their ~~Iiysiologiciil-clieniiciil rcliitioiis e s l h i ~i c d in iiliiily CIISCS, OIW is nblc to iiI'1)roiich cspcrimcutnlly thc qiicstioii of their origin, iiccordiiig to their . pliicc of forriiiitioii in the orgniiism. The cliciiiiciil structure of tlic scsunl Iioriiioncs makes it probiiblc tlint t h y lire forinctl froiii the sterols. I-low fur this triiiisforiiiiitioii uctiinlly occim iii tlic orgiiiiisiu, iindcr what conditions, niid i i i whiit situiitioii it occiirs iiiid by ~v l i i i t factors it is coiit~ollcd or may be pnthologicnlly clcr~iiiyccl iirc qiicstioiis w1iii:li iiwnit solution.