dfter hiving tliscttsscd iii tlie jircccdiiig lectures the inotlificat,ion of the sterol iiiiclclts in tllc hilt* iicids, iicutriil sapotiiiis, carrliric poisons, :ind vitiitiiiiis, let 11s turn to n cotisidcration of the Iiist Iiirpc group, t81ic discovery of which pl:ic~d tlic iliiportiilicc of tlic st.erols in nn eiitirclp new light : tltc sesitril lioriiiotic group, in which I s1i:ill inrluclc t.hc gcttcrntirc liortiioncs of tltc reproductive gltintls. Tlie coniIdietisivc biological iiirestigntions to which \vc iirc itidcbted for Icuding its to oliis problctii ii-crc cliicflp citrrietl out during t,ltc first) 25 y ~n r s of this ccntury. They p r o d t l i n t it1 thc geriiuiinl glitiitls of tlic vertebrate iind t i m i , su 1)stniiccs iirc foriiietl tlic prescticc of which is iicccssarp in coinpnrntivcly sninll quniitit,ics in thc orgii tiisin in ordw t h t the gciicfically tletcrlnincd scs iliiiy tlc.clop to maturity.
hxorditig to our 1)rcsctit ktioivlcdgc thcrc nrc iioritiiilly hormones wit.li tlisbitictivc iictiotis ; two oviirinn Iior-produced in ~i i ~i t t i ~i i i i l iind 11111~1 tlircc tyl)cs of ScSli~Il tltc lirst, piire prepitrtitioii of tlicsc tlircc types of lioriiiotics is sliowii in T:tblc 1. AS t,lic conccntriitioli of tlic lio~niotics in tlic iiiit~triil tiiiitcriiils used for t;hcir prcpiirntion is sinall, t,lic first isoliitioii of tlicsc nct.ivc substiinccs rcquircd enriclinicnt of the liirgc ortlcr of 300,000-1,000,000 times (T:iblc I). \'it11 sottic just.ilic;itioii it, h:is beeti poititcd out t1i:rt thc isoliitioii of tlic higltlp active orgilitic biocatnlystiq is rimitiiscctit3 of !.lie prcpuriit~ioii of pitre rudiorictivc elclncnts.
iitvcst.igotioti of tlic scs Itorttioties lie in tlte fiict tltiit t.Iicy ciiti rilso be regiirdetl iis tlcriviitives of cyclo-pctitonol)c~hptlro~)li~tiittitllrclic. Tlie funclarticntully distinct ph~~iologiciil futictioiis of the scs ltorrnotics o d y iiiutiifcst thctiisel\w in very stititll difl'crcnccs in their chctnicul structurc.
Tlie follictIlilr lioriiioric ~n s first found pliysiologicully :is well its cltctnic;illy l ~p iiiteitsivc work. Our knowledge r i I. hc ttiost surprising ; i n t i ititcrcsthg results of cliciiiicirl Ycnr 10'211 1113 1 1!t34 ' I ' A I ~~X 1 Fird i d t t i v t i v/ tItr /hwe w.r horiwiirw A II t I1ors I-loritiotic Iporrniilii Stiirting Ortlcr of inuterinl ciiricliuient E'olliciilnr Iioriiioiic mstronr C,,11,20, I'regnniicy uriiic .... 100 times 15. A. Iloisy iintl A. Ih~teiiniitlL Testiciiliir horrnonc iintlro-C191-13,,0~ .\lnlc iirine .... .... 100 tiiiies Ihtenniitlt nncl 'Isohcniing stcrone C21JI:J)3 Swine oviiriw .... 300,000 tiiiics Uittciiundt. ant1 \VC8tJ)~lId, Sloth ntid '~'Al%l~ 11 i'uliirdIg occicrritiy i ~i r i ~i b c r ~ oj ilte uulrottc group Nlll~lo VorIIIIIIli laolatccl froni Activity, 1 XU. in y 1 (ISstrorie .... C18113203 Owrics, pregnnncy 0.1 * urine, sttillion iirine, iutirc urine, p l m kernels 2 CEstrndiol ....