ACTION OF SEX HORMONES IN FOETAL LIFE 413 



lows that there must be a belated growth of the gonads and 

 formation of seminal vesicles in the later foetal stages which I 

 have not had an opportunity to examine, in some cases at least. 



The literature contains descriptions more or less complete of the 

 anatomy of the reproductive system of about 30 free-martins. 

 These have been tabulated by D. Berry Hart ('09-'10). All 

 agree in one fundamental respect, viz: that the gonads never 

 show the least evidence of possessing the structure of an ovary; 

 Graafian follicles have never been described. In some cases the 

 gonad is represented merely by clumps of fat, or is absent; in 

 others it is rudimentary and situated in the body cavity, or may 

 be of considerable size in the same situation, or finally may be 

 found in the groin. Whenever present it presents more or less 

 superficial resemblance to a testis, sometimes- an exceedingly 

 close resemblance. Histologically also it resembles a testis. 

 However it is probable that spermatozoa are never formed, and 

 even that the earhest stages of spermatozoa are lacking in the 

 tubules. All agree likewise in the very great reduction or com- 

 plete absence of vagina, uterus, and tubes, and the presence of 

 Wolffian ducts in a greater or lesser degree of development. 

 However, it would be merely tedious to review the variations in 

 detail. 



The very interesting question presents itself how far the modi- 

 fication of the female reproductive organs towards the male 

 side may be carried. I have already described the most extreme 

 case that I have met (no. 44, fig. 28) ; but one of Numan's cases 

 indicates that the transformation may proceed considerably 

 farther. This case seems to be well authenticated in all re- 

 spects, and on account of the rarity of Numan's publication I 

 include a full description of it : a pair of calf twins was delivered 

 by Caesarian section in 1832 at Maarssen in Holland, one was 

 male and the other was supposed to be a free-martin. Numan 

 bought the latter the following year; on examination a small 

 opening was found in the perineum a short distance below the 

 anus through which urine dropped, the urethra passed over the 

 pubic symphysis and opened externally about two hands- 

 breaths below the anus through an opening surrounded by an 



