THE TESTICLE AND THE OVARY 371 



mesentery or other tissue, or only one ovary instead of both, were 

 extirpated, and in these cases the pregnancy was continued. Further- 

 more, Kleinhaus and Schenk l found that destruction of the corpora 

 lutea of rabbits, after the ninth day of gestation, did not necessarily 

 produce abortion, but that the same operation at an earlier period 

 invariably brought the gestation to a premature end. 



Ancel 2 and Bouin have shown in a succession of papers that the 

 rabbit's uterus undergoes growth, vascularisation and muscular 

 hypertrophy after ovulation, although the ova are not fertilised 

 (e.y. owing to coition having been sterile through the vasa defer- 

 entia of the male having been cut). There is a great glandular 

 hypertrophy of the uterine mucous membrane and active secretion 

 takes place. These changes are succeeded by regression, when the 

 blood-vessels break down and corpuscles are extravasated in the 

 stroma and the glands become smaller. The regression sets in 

 about the thirteenth day, or after a period nearly equal to half the 

 duration of pregnancy. The corpus luteum begins to retrogress about 

 the same time. There is, therefore, a close parallelism U'tween the 

 growth and regression of the corpus luteum and a series of cyclical 

 changes which take place in the uterus. Ancel and Bouin have 

 shown further that there is a parallelism l)etween the development 

 of the corpus luteum and the growth of the mammary gland in 

 the rabbit (see below, Chapter XIII.). In the absence of corjwra 

 lutea neither the uterine growth nor the mammary growth take 

 place. 



Although doubt lias been expressed by some, authors 3 as to the 

 existence of the correlation it has now been abundantly established 

 by several independent investigators working on different animals. 

 O'Donoghue 4 has confirmed the results for the rabbit's mammary 

 gland. The development of the mammary tissue in the later part 

 of pregnancy has been ascribed by Ancel and Bouin to the influence 



1 Kleinhaus and Schenk, '' Experimentales zur Frage nach der Funktion 

 des Corpus Luteum," Z'-it#-li.f. <>'<!>. ". ''>">/., vol. Ixi., 1907. 



vol. Ixvii., 1909; " Sur les Fonctions du Corp Jaune Ut-statif." /.,</,-. 

 /'////x. <-t r<itl>. '/'//., vols. xii. and xiii., 1910 and 1911. (For inycinctri.-al 

 gland see also ('. R. /< '" >'"< '/' />''/., vol. Ixxii.. I'.M:>: and ('. II. .1. .,./. 

 Set., vol. cliv., 1912; and see below, Chapter XIII.. for further account and 

 i*(? f G i*c n ccs ^ 



3 Dubreuil and Regaud, "Sur les Relations fonetiom-H.^ d.-^ Corps jaunes 

 avec 1'Uterus non gravide," I., II., III., and IV.. / . /,'. -I- I" Soc. '' /!>'>'.. vol. Ixvii., 

 1909. Seealso earlier papers in vol. Ixv., 1908, and vol. Ixvi., 1909. Niskmihina, 

 on the other hand, tends to confirm Ancel and Bonin, " Kr.-herches exp.'ii- 

 mentales sur la Fonction des Corps jaun.-s." <'. II. >/e !,t >'<. <le /Hot., v..|. Ixvi.. 

 1909 



4 O'Donoghue, "The Artificial Production f C.,i].<.in Lut.-;i, /'r^-. /'/,//.. 

 Soc., Jour, of Physiol., vol. xlvi., 1913. 



