228 CORTEX 



pituitary implants even in the absence of adrenal activity. In 

 males implantation of the anterior pituitary gland or injection 

 of urine of pregnancy still stimulates the accessory sex organs. 

 However, neither procedure prevents atrophy of the testis. 667 

 Attempts to affect the adrenals by injection of various sexual 

 hormones have been negative. Thus menformon, theelin, and 

 androtin produce no observable changes in the adrenals. 

 Contrariwise, the injection of the adrenal cortical hormone 

 which supports life is without demonstrable effect on the repro- 

 ductive system. Experimenters who claimed to demonstrate 

 precocious puberty in rats by injections of the hormone and 

 other changes in the reproductive tract were misled by the 

 crudity of the extracts which they had employed. Many 

 workers in endocrinology are unaware of the ease with which 

 one can produce changes in certain organs, particularly the 

 thyroid, adrenals, and reproductive system, by injection of 

 any one of a number of non-specific substances. Thus lecithin, 

 as Jaffe" and Ranssweiler 321 showed, may produce hypertrophic 

 or atrophic changes in the sex organs after long injection. 

 Cholesterol produces marked hypertrophy of the uterus in rats. 

 Thus the average weight of the uterus in six rats injected on 

 alternate days for a month with a one per cent solution of 

 cholesterol was 0.300 grams as compared to 0.170 grams in the 

 control animals. The ovarian weights were not influenced by 

 the injections. Precocious maturity in rats (as evidenced by 

 opening of the vagina) and luteinization of immature ovaries 

 may be obtained by injecting extracts of a variety of tissues. 321 

 Great caution is, therefore, necessary before drawing any con- 

 clusions as to the existence of fundamental endocrinological 

 relationships between organs. It is necessary to exclude the 

 possibility that impurities such as lecithin, cholesterol, choline, 

 histamine, etc., which contaminate extracts of glandular 

 products, are producing the observed effects rather than some 

 hormone which one is perhaps more desirous of crediting with 

 the observed effects. As already stated many effects attrib- 



