THE OVUM 769 



The germinal spot (Wagner) is contained in the germinal vesicle. 

 Some vesicles present two germinal spots. In perfectly fresh ova the 

 germinal spots have been observed to undergo ameboid movements. 



Discharge of th'e Ovum. A ripe Graafian follicle measures f to J of 

 an inch (10 to 12 millimeters) in diameter, and presents a rounded 

 elevation, containing a plexus of bloodvessels, on the surface of the 

 ovary. At its most prominent portion, is an ovoid spot in which the 

 membranes are entirely free from bloodvessels. At this spot, which is 

 called the macula folliculi, or stigma, the coverings finally give way and 

 the contents of the follicle are discharged. For a short time anterior to 

 the rupture of the follicle important changes have been going on in its 

 structure. In the first place, the portion situated at the very surface of 

 the ovary undergoes degeneration, by which this part of the wall gradu- 

 ally becomes weakened. At the same time, at the other portions of the 

 follicle, there is a proliferation of cells which project into 

 the interior, and an extension into the interior of blood- 

 vessels in the form of loops. These changes, with an 

 increase in the pressure of liquid and the degeneration 

 at the macula, cause the follicle to burst ; and with the 

 liquid, the discus proligerus and the ovum are expelled. F ? g> , 2o8 - "~ Pri ~ 



moraial ovum -with 



The formation of a cell-growth in the interior of the two germinal vesicles 

 follicle is the beginning of the corpus luteum ; and this % 

 occurs some time before the discharge of the ovum of a newborn child 

 takes place. 



The time at which the follicle ruptures, particularly with reference 

 to the menstrual period, is not definite ; but it is certain that while sex- 

 ual excitement probably hastens the discharge of an ovum by producing 

 a greater or less tendency to congestion of the internal organs, ovulation 

 takes place independently of coition. The opportunities for determin- 

 ing this fact in the human female are not frequent ; but it has been 

 fully demonstrated by observations on the inferior animals, and there 

 is now no doubt in regard to the identity of the phenomena of rut and 

 of menstruation. At stated periods marked by the phenomena of men- 

 struation, one Graafian follicle and sometimes more than one 

 becomes distended and usually ruptures and discharges its contents into 

 the Fallopian tubes. This discharge of an ovum or ova may occur at 

 the beginning, at the end, or at any time during the continuance of the 

 menstrual flow. On this point the observations of Coste seem entirely 

 conclusive. In a woman who died on the first day of menstruation, he 

 found a recently-ruptured follicle ; in other instances, at a more ad- 

 vanced period and toward the decline of the menstrual flow, he found 

 evidences that the rupture had occurred later ; in the case of a female 



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