24 OBSTETRICS. 



details the egg of the chick. The ovum also contains within its 

 capsule or membrane, which is called the yelk membrane, a granular 

 fluid termed the yelk, and in the centre of the yelk a little vesicle, 

 the germinal vesicle, and on the walls of the germinal vesicle its 

 nucleus is seen, named the macula germinativa, or germinal spot. 

 As each Graafian vesicle rises to the surface of the ovary it bursts, 

 and allows the contained ovum to escape, which is seized by the 

 fimbrioe of the Fallopian tube, and transmitted to the uterus. The 

 cavity of the Graafian vesicle, (which still remains in the ovary,) be- 

 comes filled up either with a clot of blood, or a new deposit, which, 

 assuming a yellow colour, is called from that circumstance, corpus 

 luteum, or yellow body. There is no correspondence between the 

 number of corpora lutea found in the ovaries of a woman, and the 

 number of children she may have borne, as ova are being constantly 

 discharged irrespective of fecundation, hence the corpus luteum is no 

 evidence of previously existing pregnancy. 



MENSTRUATION AND ITS DISEASES. 



By the term menstruation, is understood that function in the 

 female economy by which a certain amount of sanguineous fluid is 

 eliminated by the uterus, and discharged from the vagina every 

 month. This discharge, from its occurring at this regular interval, 

 is called the menses, or catamenia, and the female in whom it so 

 takes place is said to be regular. 



This function generally commences at the age of puberty, which m 

 this country is about fourteen or fifteen, and lasts till about forty-five, 

 when it disappears ; to this latter period is often applied the terms, 

 critical period, change of life, &c. During the whole of a woman's 

 menstrual life she is capable of conceiving ; after this, her repro- 

 ductive function ceases. The approach of puberty is announced by 

 other changes than those mentioned. The mammae are developed, 

 the form becomes rounded, the pelvis expands, and the pudendum is 

 covered with a growth of hair. The flow generally returns every 

 twenty-eight days, and lasts from four to six, and the amount dis- 

 charged varies from four to eight ounces, though about this there is 

 no certainty, as every woman is a law to herself; what would be 

 a profuse discharge in some, is merely normal in others. The first 

 menstrual flow is generally preceded by languor, lassitude, pain in 

 the back, headache, chilliness, &c., which generally disappear whe« 

 the discharge takes place. The after occurrences are often unac- 

 companied by any premonitory or attendant symptoms. The theo- 

 ries that have been brought forward to explain the efficient cause of 

 menstruation are too numerous, and too unsatisfactory to detain us 

 here. The most popular is that which looks upon the maturation 

 and escape of ova as the efficient agent. It is said that every twenty- 

 eight days a Graafian vesicle rises to the surface of the ovary, and 



