558 SWALE VINCENT 



doubt thatij if large doses be administered to small animals, serious 

 results may accrue, as in the case of other tissue extracts. Extracts of 

 ovary hinder the coagulation of the blood both in vitro and in the cir- 

 culating blood. 



It is said that ovarian extracts have a well marked effect upon metab- 

 olism. Administration of ovary substance produces no effects upon gase- 

 ous metabolism in normal sexually mature animals, but in castrated ani- 

 mals, both male and female, the reduced metabolism may be restored to 

 normal, or even rise thirty to fifty per cent above this level (Lowy and 

 Richter (a)). According to Beloff, extracts of ovaries freed from corpora 

 lutea give rise to an increase in the oxygen intake and the nitrogen excre- 

 tion, while preparations from the corpora lutea themselves induce diminu- 

 tion of oxygen intake and increase in the elimination of water. The 

 effects of ovarian material on the carbohydrate and mineral metabolism 

 are not very clearly indicated by the results of experiments so far per- 

 formed. 



It is not safe to allege that any of the above effects are certainly char- 

 acteristic of and specific for ovarian substance. Many of the same results, 

 at any rate, may be produced by the giving of other organ and tissue 

 extracts. It has been supposed that the ovary has a specific action on 

 uterine muscle, since the contractions of the uterine muscle of the cat 

 exhibit increase in frequency resulting from local action of ovarian extract 

 (Barry, 1915-16). 



In some species, at any rate, a part of the effects described above may 

 be due to the "interstitial gland." So far as I am aware, no investigator 

 has studied separately the effects of administration of ovary without any 

 interstitial gland. 



Structure of the Corpus Luteum 



The classical description both of the development and of the micro- 

 scopic anatomy of the fully formed corpus luteum is that of Sobotta (&) 

 (/). In the mouse, the epithelial cells are large and polygonal in shape, 

 measuring 20 ^ or more in diameter. They contain a substance known as 

 lutein, a yellowish fatty substance, which is for the most part disposed ec- 

 centrically, but it may almost fill the cell. The peripheral cells are most 

 often free from lutein, while those in the center contain the largest 

 amount. Generally speaking, the older a corpus luteum is, the more of the 

 fatty substance does it contain. The nucleus is rounded. 



The body consists of columns of luteal cells separated by intervening 

 trabeculse, the fibrous tissue of which contains numerous blood vessels. 

 These trabeculse converge inwards from the surrounding ovarian stroma 

 to a central strand or plug of connective tissue, in which there are no 

 luteal cells occupying the axis of the nodule (see Fig. 1). The columns 



