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The Functional Correlation between the Ovaries, Uterus, and 

 Mammary Glands in the Rabbit, with Observations on the 

 (Estrous Cycle. 



By J. Hammond, M.A., and F. H. A. Marshall, Sc.D. 



(Communicated by Dr. F. Gr. Hopkins, F.E.S. Received January 22, — Read 



March 5, 1914.) 



[Plates 17 and 18.] 



Recent experimental work has resulted in proving that there is a definite 

 functional correlation between the growth of the corpora lutea in the 

 ovaries and the hypertrophy of the mammary glands (Ancel and Bouin and 

 O'Donoghue). In the present paper experiments are described showing that 

 this hypertrophy in rabbits that have never been pregnant may be so con- 

 siderable as to lead to the production of milk, the secretion of which may 

 be temporarily increased by the injection of pituitary extract. Further 

 experiments are recorded showing that the uterus is not a necessary factor 

 in the development of the mammary gland. The influence of experimentally 

 produced corpora lutea upon the uterus is also described. 



The Infitience of the Ovaries upon the Mammary Glands. 



It is well known that the mammary glands in man begin to undergo 

 enlargement at the time of puberty in correlation with the increase in 

 ovarian activity. Apart from this pubertal growth which is more or less 

 permanent, there is known frequently to be a slight swelling of the glands 

 at each menstrual period. A similar process takes place in the sow and 

 probably in other mammals at the " heat " periods (Marshall). In the virgin 

 rabbit we have noticed a growth of the mammary ducts in six cases prior 

 to ovulation, but the cell proliferation, though quite definite, did not extend 

 to the glandular tissue. Experiments were undertaken to determine if the 

 growth could be increased by injecting foetus extract, with a view to bringing 

 further evidence to bear upon the hypothesis, put forward by Starling and 

 Lane-Claypon, that the anabolic changes involved in mammary hypertrophy 

 are dependent upon a foetal hormone. The results, however, were negative 

 in each case. 



The following are the details of this series of observations. The extract 

 was made by grinding the fresh foetuses with sand and extracting with 

 Ringer's fluid. The extract was then boiled and filtered. In the first three 

 experiments described below 39 rabbit foetuses were employed : — 



