August 20, 1920] 



SCIENCE 



181 



In my former papers I have discussed certain 

 factors used as definite indicators of maleness 

 and femaleness, and have attempted to point 

 out the difficulty of properly interpreting the 

 observations. With considerable reticence 1 

 was inclined to give some weight to psychical 

 behavior in cases of the most extreme type of 

 reactions; but I wish again ito emphasize the 

 absolute unreliability of closely graded indi- 

 cations of psychical behavior of rats and 

 guinea pigs as an indication of their sexual 

 nature. It is, in my opinion, going to an ex- 

 treme when one asserts as does Sand: 



This somatic hermaphroditism was combined with 

 a decided bisexualism of the psycho-sexual char- 

 acter, in that the animal showed, even during the 

 course of a single hour, momentary change from 

 female to a decided male character, according to 

 the animals (males, newly-born young ones, fe- 

 males) with whom it was brought into contact.' 



Sand's general conclusions in reference to 

 sex gland growth seem entirely superfluous in 

 the light of my own results. In explaining his 

 failure to obtain growths of ovarian grafts in 

 non-castrated infantile male animals he as- 

 sumes a rather indefinite type of " Immunity " 

 on the part of the host, towards the implanted 

 tissue, 'and explains it as follows: 



In every organism are found certain substances 

 which are necessary for the sexual glands, and 

 these substances the latter try to obtain to the 

 greatest possible extent. The normally situated 

 non-transplanted gonads have the best chance of 

 being able to absorb these substances, for which 

 reason heterological (perhaps also homological) 

 gonads, transplanted on normal organisms, can 

 not get enough of these substances and therefore 

 perish. Homological and heterological gonads, 

 which have been transplanted at the same time to 

 the same organism, are both able to grow in, hav- 

 ing both about the same opportunity of absorbing 

 the substances. 



Further the phenomenon that ovaries ingrafted 

 in the testes find good conditions for developing 

 there, can probably be explained by a similar 

 theory, in that the substance of the normal male 

 organism, necessary for the gonads, are perhaps 

 stored up in the testes, both kinds of gonads thus 

 being able to make use of them. 



"Italics mine. 



So far as the persistence and growth of rat 

 gonads is concerned, this theory is entirely un- 

 necessary for I have been able to obtain 

 growths of ovarian grafts, subcutaneously, 

 intra-muscularly, and intra-peritoneally, and 

 without difficulty, in young male rats one of 

 whose sex glands was intact and normal. 



This part of my work was begun in 1917 

 and some animals bearing transplants are still 

 living; but a detailed account of this work is 

 nearing completion and will appear as the 

 third paper of a series " On the Physiological 

 Properties of the Gonads as Controllers of 

 Somatic and Psychical Characteristics." 



I have obtained persistence of both types 

 of sex glands grafts after transplantation into 

 young animals of the opposite sex, one of 

 whose sex -glands had been removed to furnish 

 material for other grafts, while the second 

 gland of the host remained imdisturbed. In 

 the case of the ovary, the graft, after persist- 

 ing eight and one half months in a male 

 animal with an intact testis, presents all the 

 features of a normal ovary of similar age 

 excepting corpus luteum tissue and the pres- 

 ence of a larger number of atretic follicles. 

 Normal follicles of all sizes are present — ^pri- 

 mordial follicles, more mature ones showing 

 the b^inning of the follicular cavity, mature 

 follicles, and even those showing polar body 

 formation in the ovum. The follicles seem, not, 

 however, to go on in their normal behavior to 

 ovulation and corpus luteum formation, but 

 undergo atresia. The fate of a follicular mass 

 can be traced to its complete conversion into 

 interstitial material. In this behavior of the 

 follicles of the grafts, they are very similar to 

 corresponding structures of the young female 

 sex gland before the age of sexual maturity. 



With the testicle grafts the results are not 

 quite so striking due to the fact that mam- 

 malian testis transplantations, without excep- 

 tion so far as I am aware, results in the loss 

 of the germinal epitheliiun. The grafts re- 

 semble considerably a cryptorchid testis in 

 that both retain the well-rounded seminiferous 

 tubules, but all that remains of a cellular char- 

 acter are Sertoli cells. The same disappear- 



