ORGANS OF INTERNAL SECRETION 343 



dentally at the time of the operation. So able and experienced 

 an operator as Bland Sutton 1 has recently testified to the 

 extraordinary difficulty experienced in removing the whole of 

 the ovarian tissue in ovariotomy, and the distinguished French 

 obstetrician, Lucas-Champonniere, 2 has expressed himself in the 

 same sense, so that there is nothing unreasonable in the assump- 

 tion that the operation of removal is sometimes incomplete 

 when performed on pregnant women. 



Daels 3 has recently recorded a large series of experiments 

 upon guinea-pigs and rats in which he found that bilateral / 

 castration invariably interrupted the course of pregnancy' 

 during rather more than the first half of its duration. In 

 control experiments portions of mesentery or other tissue, or 

 only one ovary instead of both, were extirpated, and in these 

 cases the pregnancy was continued. Furthermore, Kleinhaus 

 and Schenk 4 found that destruction of the corpora lutea of 

 rabbits, after the ninth day of gestation, did not necessarily pro- 

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

 invariably brought the gestation to a premature end. 



According to Ancel and Bouin, 5 the rabbit's uterus undergoes 

 growth, vascularisation, and muscular hypertrophy after ovula- 

 tion even although the ova are not fertilised (e.g. owing to the 

 vasa deferentia of the male having been cut). These changes 

 are said to be followed by regression, which sets in after the 

 thirteenth day. According to Ancel and Bouin, therefore, 

 there is a close parallelism between the growth and regression of 

 the corpus luteum and a series of cyclical changes which take 

 place in the uterus. There is also said to be a parallelism 



1 Bland Sutton, " A Clinical Lecture on the Value and Fate of Belated 

 Ovaries," Medical Press, vol. cxxxv. (July 31) 1907. 



2 Lucas-Champonnicre, " Sur une Observation de Graffe Ovarienne Suivie 

 de Grossesse," Jour, de Med. et de Chirurgie Pratiques, vol. Ixxviii. (May) 

 1907. 



3 Daels, " On the Relations between the Ovaries and the Uterus," Surgery 

 Oyncecology and Obstetrics, vol. vi., 1908. 



4 Kleinhaus and Schenk, " Experimentales zur Frage nach der Funktion 

 des Corpus Luteum," Zcitschr. f. Oeb. u. Gynak., vol. Ixi., 1907. 



5 Ancel and Bouin, " Sur la Fonction des Corps jaunes," C. R. de la Soc. 

 de BioL, vol. Ixvi., 1909 ; " Le DeVeloppement de la Glande Mammaire 

 pendant la Gestation est determine par le Corps jaune," C. R, de la Soc. de 

 BioL, vol. Ixvii., 1909. 



