130 INTRODUCTION TO SEXUAL PHYSIOLOGY 



(Carcinus mcenas) is infected with the cirrhipede, Saccidma, 

 certain of the female characteristics may develop without the 

 testes being destroyed. 



Experimental Sex Reversal and Inter sexuality. — That the 

 chromosome constitution of the sexes may be overridden is 

 shown further by those experiments in which ovaries have been 

 transplanted into males and testes into females, the animals 

 employed having been previously deprived of their own gonads. 

 It has been shown above that in the higher animals, at any rate, 

 the secondary sexual characters are dependent upon the influence 

 of stimulating substances secreted by the sex glands. The 

 experiments of Steinach, Lipschiitz, Athias, Sand, Moore, and 

 others have demonstrated further that an intersexual condition 

 or almost complete sex reversal may be brought about by ovarian 

 or testicular transplantation after previous castration. Thus 

 if ovaries are grafted into castrated male rats or guinea-pigs, 

 not only will the mammary glands develop and secrete milk, but 

 the sexual reflexes and psychic behaviour may hkewise change. 

 Guinea-pigs so operated upon may display the " tail-erect " 

 reflex of copulation, and the " kick-guarding " reflex, which 

 is used by the female to ward of? the male when the former is 

 not in a condition of oestrus. Conversely, in spayed females 

 with transplanted testes, the clitoris becomes transformed into 

 a penis-like organ, and even the horny styles, which are character- 

 istic of that organ in the male guinea-pig, undergo a marked 

 development. Experiments which illustrate the same point 

 have been performed upon birds by Goodale, Pezard, and 

 Zawadowsky. Thus Pezard transplanted an ovary into a 

 castrated cock and found that it caused the suppression of such 

 male characters as the spurs. 



Experimental hermaphroditism has also been successfully- 

 performed, as in Sand's experiments upon rats, when the ovaries 

 were grafted within the tissue of the testes. The results of 

 experimental hermaphroditism have been various, some animals 

 displaying to a large extent the characters and psychic behaviour 

 of both sexes {e.g. development of mammae and normal penis 

 with reversible sexual behaviour). According to Lipschiitz the 

 results probably depend u])on variation in the (juantitative 

 production of the male and female hormones at different times, 

 these tending to act antagonistically. 



