430 Mr. Hammond and Dr. Marshall. Correlation between 



earlier stages of pregnancy, and that the corpora lutea might be unable to 

 exert their influence upon the mammae excepting through the mediation of 

 the uterus. The changes which the uterus undergoes (to be described below) 

 as a result of the formation of the corpora lutea lent a certain amount 

 of evidence in favour of this view. It had, however, been shown that the 

 removal of the uterus in young rabbits has no effect upon the subsequent 

 growth of the ovaries, for animals so operated upon after becoming mature 

 are capable of copulation, ovulation, and the formation of corpora lutea just 

 as though they had not undergone hysterectomy ; but the effects (if any) of 

 the removal upon breast development were not recorded (Carmichael and 

 Marshall). 



The following is an account of our experiments : — 



(22) The uterus was removed from a virgin rabbit when 10 months old. 

 Subsequently the animal copulated and was killed 25 days after copulation. 

 No remains were found of the uterus or Fallopian tubes, and one ovary was 

 missing, presumably having become absorbed as a result of vascular inter- 

 ference at the time of the hysterectomy operation. The other was normal 

 and contained nine corpora lutea. The alveoli of the mammary glands 

 showed signs of atrophy, but it was clear that they had undergone a con- 

 siderable growth previously. Both alveoli and ducts contained a secretion. 



(23) The uterus was removed from a virgin rabbit when 3 months old. 

 After it had reached maturity it was allowed to copulate several times, and 

 killed 12 days after the last copulation. One ovary contained four corpora 

 lutea, the other having undergone atrophy. No remains of uterus or 

 Fallopian tubes could be found. The mammary glands showed a great 

 development of alveoli but no milk was present (fig. 3). 



(24) The uterus was removed from a virgin rabbit when 3 months old. 

 After it had reached maturity it was allowed to copulate several times, and 

 was killed 9 days after the last copulation. The left ovary contained 

 several corpora lutea. Small pieces of the Fallopian tube were found 

 attached to it. The right ovary had undergone partial atrophy presumably 

 as a result of vascular interference, and there was a small piece of the right 

 Fallopian tube with a cyst. The mammary glands were well developed, the 

 alveoli being filled with a secretion. 



(25) The uterus was removed from a virgin rabbit when 3 months old. 

 The rabbit subsequently copulated. A little serous fluid could be squeezed 

 from the nipples on the 22nd and 27th days after copulation. The rabbit 

 copulated again on the 28th day (August 14). A few drops of fluid were 

 expressed 25 days afterwards (September 8), when it copulated again and 

 was immediately killed. The mammary glands were well developed. The 



