174 EXPERIMENT STATION RECORD. [Vol. 41 



pregnant guinea pig, corresponding to the cycle in the ovary and uterus. Cell 

 division and other proliferative phenomena are at their maximum during the 

 period of heat and ovulation, and at their minimum from the sixth tf> about the 

 fifteenth day after ovulation. The presence of a functioning corpus luteum 

 seems to inhibit proliferation. 



II. The changes in the pregnant guinea pig, the effect of the lutein injec- 

 tions, and the correlation between the cycle of the uteru^s and ovaries and the 

 cycle of the mammary gland (pp. 305-321). — In 26 normal guinea pigs the 

 mammary gland vras examined during different periods of pregnancy. Pro- 

 liferation becomes regular only after the twenty-fourth day, when gestation is 

 about two-fifths over, and continues apparently luitil lactation becomes well 

 established. When abortion took place not more than 15 days before term, the 

 gland changed from a proliferating to a secreting organ. In cases where it 

 was possible to remove the ovaries in the early stages without causing abortion, 

 no proliferative changes occurred. Extii'pation of the corpora lutea during 

 pregnancy induced a new ovulation and with it the primary proliferation in 

 the mammary gland. Intraperitoneal injections of Uitein (fi-ora the cow) did 

 not affect proliferation. 



The relation of the ovary to the uterus and mammary gland from the ex- 

 perimental aspect, L. Loeb (Surg., Gynecol., and Obstet., 25 (1911), No. 3, pp. 

 300-315, fig. 1). — In this paper the author presents a general review of the 

 literature and an interpretation of the observations of others in the light 

 of his own publications, some of which have been previously noted (E. S. R., 

 27, p. 174). 



Ovulation in some species of mammals is accompanied by marked degenera- 

 tion of the larger follicles of the ovary. In forms where the production of 

 corpora lutea is not periodic but initiated by the act of copulation, the cells 

 surrounding the degenerating follicles enlarge and assume a glandular appear- 

 ance. It is suggested that the use of the term interstitial gland be restricted 

 to glandular tissue of this type. The presence of a uterine placenta hinders 

 rupture of the corpus luteum of pregnancy. The existence of a corpus luteum 

 prevents ovulation in most mammals. Corpora lutea have been produced ex- 

 perimentally without ovulation in rabbits and guinia pigs by cutting a mature 

 follicle. Heat is probably brought about by absence of a corpus luteum and 

 pi-esence of mature follicles in the ovary. The corpus luteum does not inter- 

 fere with the maturation of follicles. 



The relation between the ovary and the mammary gland has not been com- 

 pletely analyzed. During heat and subsequent to ovulation, the gland grows 

 by proliferation of cells. After the corpus luteum develops, these changes cease 

 and the gland secretes milk. The response of the gland to corpus luteum 

 extracts varies in different animals. 



On the behavior of the mammalian ovary and especially of the atretic fol- 

 licle towards vital stains of the acid azo group, H. M. Evans (Proc. Soc. 

 Expt. Biol, and Med.. IS (1916), No. 4, pp. 80, 81).— By administering dyes of 

 the acid azo group to the female mammal — dogs being apparently the chief 

 subject of experiment — the author finds that he can identify those ovarian fol- 

 licles that are about to undergo atresia, but which have not yet shown any 

 morphological changes. The granular cells of follicles in the preliminary stage 

 of retrogression take up the dye and store it as cytoplasmic granules. " The 

 conditions which bring about this reaction are typically seen in the atresia 

 which always overtakes the next succeeding crop of Graafian follicles after 

 fertilization of the preceding crop, but this behavior is not repeated further in 



