CHANGES IN THE OVARY 133 



period (see p. 64), while, according to Raciborsky, this is also the 

 commonest season for fertile coition. 1 Moreover, the facts narrated 

 by Bryce and Teacher, in a recent memoir on the early development 

 and embedding of the human ovum, render it extremely probable 

 that the ovum described had been discharged shortly after the 

 cessation of the last menstruation. 2 



With regard to the question as to whether any special stimulus 

 is necessary to induce ovulation in women, Oliver 3 is of opinion that 

 whereas it sometimes may occur spontaneously, it is more than 

 probable that it " may be and often is accelerated by coitus," since 

 at this time there is "an increased determination of blood to the 

 whole genital tract." 4 



This suggestion receives some support from an experiment by 

 Clark, 5 who caused the rupture of a Graafian follicle artificially in a 

 freshly removed ovary by injecting carmine gelatine into the vessels 

 and so raising the ovarian blood pressure. 



The causes which determine the rupture of the Graafian follicle 

 are also discussed by Heape, who is of opinion that this is brought 

 about in the rabbit by the stimulation of erectile tissue, and not 

 simply as the result of internal pressure arising from increased 



1 Raciborsky, Traite de Menstruation, Paris. See also Luciani, Human 

 Physiology, English Edit., vol. v., London, 1921. Oliver thinks that fertilisation 

 may take place at practically any time in the inter-menstrual period ("Fertilisa- 

 tion Time and the Inception of Gestation in Women," Edin. Med. Jour., 1914. 

 See also Fraenkel, " Ovulation, Konzeption und Schwangerschaf tsdauer," 

 Zeitsch. five Oeb. und Gyn., vol. Ixxiv. ; and Tschirdewahn, " Ueber Ovulation, 

 Corpus Luteum und Menstruation," Zeitsch. fur Geb. und Gyn., vol. Ixxxiii. 



* Bryce and Teacher, Contribution to the Study of the Early Development and 

 Embedding of the Human Ovum, Glasgow, 1908. 



3 Oliver, " A Study of Fertilisation with Beference to the Occurrence of 

 Ectopic Pregnancy," Edin. Med. Jour., vol. liv., 1902. 



4 Pregnancy, and therefore ovulation, have been known to take place before 

 the onset of menstruation. Pregnancy may also occur during amenorrhoea (e.g. 

 at the commencement of the menopause) and during the lactation period, when 

 menstruation is often in abeyance. Again, it is stated that ovulation has been 

 noted during infancy, before any of the other indications of puberty have been 

 observed (Webster, " The Biological Basis of Menstruation," Montreal Medical 

 Journal, April 1897). Further, it will be shown below (p. 378) that the ovaries 

 can maintain their normal functions after the removal of the uterus. It would 

 seem, therefore, that ovulation mat/ occur spontaneously in women, and is not 

 necessarily connected with either menstruation, oestrus, or coitus. On the other 

 hand, there is evidence that ovulation is usually dependent upon the occur- 

 rence of the sexual orgasm in women. Galabin records a case of a woman who 

 married under the age of twenty, and lived in married life with two husbanda 

 in succession, and who, when she had passed the age of forty, experienced the 

 sexual orgasm in coitus for the first time, and from that day dated her first and 

 only pregnancy (Manual of Midwifery, 6th Edition, London, 1904). That the 

 orgasm (which is characterised by the erection of the clitoris, etc., accompanied 

 by pleasurable sensations) is not absolutely necessary for conception is shown 

 further by pregnancy occasionally occurring in women who are " impotent." 



5 Clark, " The Origin, Development, and Degeneration of the Blood- Vessels 

 of the Human Ovary," Johns Hopkins Hospital Reports, vol. ix,, 1900. 



6 Heape, " Ovulation, etc.," Proc. Roy. Soc., B., vol. Ixxvi., 1905. 



