88 INTERNAL SECRETIONS OF THE OVARY 



attempt to produce an active picrate extract (156-7), have very 

 recently reported the production of a water-soluble extract by a 

 new method. These authors (5) use an initial baryta saponifi- 

 cation of the placenta. After filtering through ' jean,' the 

 filtrate is extracted with butyl alcohol,which is evaporated down 

 and the residue taken up in hot water. This is then extracted 

 with ether, and again evaporated down. After dissolving in 

 alcohcl, and re-saponification with barium hydroxide, the 

 barium can be removed to leave an aqueous solution. The 

 yields obtained are satisfactory (about 200 r.u.k.). The weight 

 of the unit is about -oi mgm. and some 10-50 units per c.c. 

 are obtained. This process, and that of Zondek and Brahn, 

 may be relied upon to give consistent results. Steinach and 

 co-workers (593) report the preparation of a highly active 

 aqueous extract, in which the end product is said to have an 

 activity of 500 m.u. per c.c. 



Nomenclatuvc. To refer to the cestrus-producing hormone of 

 the ovary as ' the ovarian hormone ' or as ' the female sex 

 hormone ' is to pre-suggest that only one exists. ' Feminin ' 

 used by Glimm and Wadehn and by Fellner is open to the same 

 criticism. The term ' follicular hormone,' though showing its 

 connection with the follicular phase of the cycle, is misleading 

 in so far as it suggests elaboration only by the Graafian follicle. 

 ' Folliculin,' used by Courrier and others, suffers from the same 

 disadvantage. ' Menformon ' used by Laqueur, appears to be 

 meaningless, but ' thelykinin,' suggested by Loewe is more 

 suitable. The latter author uses the term ' thelytropine ' to 

 include both the oestrus-producing hormone and the luteal 

 hormone, which he terms ' thelystasin.' Blotevogel, Dohrn and 

 Poll use ' tokokinin ' to include all sex hormones. A name is 

 clearly advantageous for descriptive purposes, and since the 

 substance in question has not adequately been shown to produce 

 any features other than those characteristic of oestrus, the name 

 ' oestrin ' (503) will be used here. 



[b) CHEMICAL PROPERTIES 



The major part of the work on the chemical properties of 

 oestrin was carried out with the fat -soluble extracts, which 



