232 Gonadotrophic Effects in Rhesus 



mal, as viewed directly during an exploratory laparotomy, often appear as red 

 rings about the numerous growing iollicles. 



Such evidences of overstimulation are occasionally met with in untreated 

 animals, in which the ovary grows excessively by virtue of the abnormally 

 large number of follicles, the surface phenomena of congestion just described, 

 and blood follicles. This condition may persist over a number of menstrual 

 periods. 



The excessive congestion inevitably leads to degeneration of the grandulosa 

 and soon to regression of the follicles which is extremely rapid, as often de- 

 termined by palpation, twice corroborated by successive exploratory laparo- 

 tomies and frequently by a single laparotomy after the treatment. The rapid 

 regression of the ovaries was reflected in the premature onset of menstruation, 

 which frequently occurred as early as 4 to 6 days after the regression became 

 evident, shortening the cycle to 19, 20, or 21 days. Occasionally the expected 

 bleeding did not occur but, instead, a long period of amenorrhea set in. This, 

 again, was neatly related to the time of year, for amenorrheic periods were 

 likely to follow treatment in March and rarely occurred from October to 

 January, when recovery was generally prompt; the treated female resumed 

 normal menstrual cycles and thereafter ovidated spontaneously. 



The nonpredictability of the adult rhesus monkey may, however, be illus- 

 trated by the following bizarre case. 



After a series of anovulatory cycles female No. 678 ^vas (in March) treated with FSH-Jensen 

 -I- Follutein 1:10, with little or no effect. No bleeding took place until June 10. On June 23, 

 which is well within the anestrum or non-breeding season of the rhesus monkey, she con- 

 ceived! She carried her baby to term and nursed it normally. 



Injections without Effect. As already pointed out, refractoriness of the adult 

 rhesus monkey to gonadotropes becomes greater as the nonbreeding season 

 characteristic of the species approaches, namely the spring of the year. Normal 

 females which suddenly stop ovulating may become absolutely unresponsive 

 to huge quantities of the hormone. Animals whose ovaries are unresponsive 

 to their intrinsic hormones in the fall and winter are usually not to be stimu- 

 lated by exogenous gonadotropes. But even in these one meets with the great- 

 est surprises. In other words, the writer has not been able effectively to predict, 

 from a prior study of the animal, what the effect of treatment might be, except, 

 of course, in the case of obviously sick individuals. 



Antihormones play no part when such small dosages are administered over 

 so short a period of time, for it has happened that the second treatment with 

 the same material has met with greater response than the first.^ 



Kind of Hormone. Gonadogen again proved itself an active stimulator of 

 the monkey ovary and seems on the whole a very good gonadotrope. FSH- 

 Jensen and FSH-Abbott made a very good showing in the small series of 

 experiments here reported, when used without the admixture of APL (Follu- 

 tein). When Follutein was added to Jensen's FSH in the proportion of 2 of 

 Follutein to 1 of FSH, the results seem less favorable, but yet stimulation re- 



