98 



BIOLOGIC BASIS OF SEX 



B^\^ 



Fig. 2.14. Hi.Ntolojiic m'X rraiisl'ormation in the te.sles uf cluck eiiil)iyu« lrcate(i with fe- 

 male sex hormones. A. Ovotestis produced from a left testis by treatment with a dose of 

 0.2 mg. of estriol. Note the presence of a thick cortex peripherally, and the reduction of the 

 testicular tissue to a hilar mass of medullary cords. The intervening highly vacuolated tissue 

 is characteristic of ovarian medullary cords. B. Section through the cortex and medullary 

 region of a left tcslis coinplolcl}- transfoinied into an ovary by a dose of 2.0 mg. of estrone. 

 Note the thick cdilrx (aboxc) coxcicd \>y a liciniinal epithelium, and the loss of structure 

 in the medullary ii'gioii Ixlow. (From B. H. W'illior, in Sex and Internal Secretio7is, 2nd ed., 

 The Williams & Wilkins Co., 1939.) 



reaction are found due to the different liisto- 

 logic constitution of the right and left pri- 

 mordia, and the results also differ when 

 different forms of the male hormone are em- 

 ployed. After treatment with testosterone 

 the cortex of the left ovary is reduced in 

 thickness and shows degenerative changes; 

 however, it does not entirely disappear. At 

 the same time there is hypertrophy of the 

 medulla and some of its cords acquire the 

 solid structure of testis cords. The result is 

 an ovotestis. Because of its predominantly 

 medullary constitution the rudimentary 

 right ovary is converted superficially into 

 a testis-like gonad. The medullary mass 

 hypertrophies and some of the cords arc 

 transformed into testis cords. In general, 

 larger amounts of hormone are required to 

 transform ovaries than for the conversion 

 of testes (for summaries see Willier, 1939; 



Wolff, 1950). After hatching there is a tend- 

 ency for experimentally modified gonads to 

 revert toward the original sex (Wolff, 1938) . 

 Similar conditions of reversal have been 

 produced in the embryonic gonads of ducks 

 by hormone treatment (Lewis, 1946) . 



The problem of the jiaradoxical action of 

 hormones presents itself again in the case of 

 a^•ian gonads. Certain male hormones of 

 ui'inary origin (androsterone, dehydro-an- 

 drostcrone) have a marked feminizing ef- 

 fect, like that produced by t'cnuile hormones. 

 In relatively large doses both substances 

 induce cortical differentiation in testes, es- 

 pecially the left, which may be transformed 

 into an" ovotestis (Willier, 1939; Wolff 1938). 

 Other androgenic substances have like ef- 

 fects, but again it has been shown that they 

 ai-e not jiroduced by low dosages. However, 

 as the concentration of the hormone is raised 



