5S 



to you if you could communicate to me the inclination and force at 

 some points. In the mean time I will occupy myself with the dis- 

 cussion of the two horizontal forces ; unfortunately the number of 

 determinations serving for this purpose is much smaller. For North 

 America those recorded by Lamont in Dove's ' Repertorium ' are 

 for the most part in comparatively low latitudes. 



May 1, 1851. 

 The EARL OF ROSSE, President, in the Chair, 



A paper was read, entitled " An account of two cases in which 

 an Ovule, or its remains, was discovered after death in the Fallopian 

 tube of the unimpregnated human female, during the period of 

 Menstruation." By H. Letheby, M.B. Communicated by W. B. 

 Curling, Esq., F.R.S. Received Feb. 20, 1851. 



At the commencement of the paper the author refers to the opi- 

 nions of Drs. Power, Lee, Paterson, Barry, Girdwood, and Wharton 

 Jones of this country, and also to those of MM. Valentin, Negrier, 

 Pouchet, Gendrin, Raciborski, and Bischoff on the continent, re- 

 specting the supposed nature of the physiological phenomena mani- 

 fested during the peirod of menstruation ; and he mentions the law 

 of Bischoff, namely, that "the ova formed in the ovaries of the 

 females of all mammiferous animals, including the human female, 

 undergo a periodical maturation and exclusion quite independently 

 of the influence of the male seminal fluid. At these periods, known 

 as those of 'heat' or 'the rut' in quadrupeds, and 'menstruation' in 

 the human female, the ova which have become mature, disengage 

 themselves from the ovary and are extruded. If the union of the 

 sexes takes place at this period, the ovum is fecundated by the 

 direct action of the semen upon it, but if no union of the sexes 

 occurs, the ovum is nevertheless evolved from the ovary, and enters 

 the Fallopian tube where it perishes." He states, however, that the 

 arguments which have been advanced in support of this opinion 

 in respect of the humajn female, are entirely of an analogical cha- 

 racter; and that although the ovaries of women who have died 

 during the menstrual period have been frequently examined, and 

 Graafian follicles found in a recently ruptured state, yet the dis- 

 covery of the liberated ovule had not, so far as the author was aware, 

 ever been detected. The importance of his cases rests upon three 

 grounds, namely, — 1st, the circumstances under which the women 

 had died ; 2ndly, the finding of recently ruptured Graafian follicles ; 

 and Srdly, the discovery of the ovule and its remains in the fluid 

 matter of the Fallopian tubes. 



In the first of the cases recorded, the woman died during a men- 

 strual period. She had been an inmate of the London Hospital for 

 twenty-four days before her death, where she was closely watched 

 day and night by a nurse, in consequence of her having attempted 



