556 



UTERUS AND ITS APPENDAGES. 



The augmentation in bulk of the follicle is, 

 in the first instance, due almost entirely to an 

 increase in its fluid contents. It is probable 

 that this fluid is supplied by the minute ca- 

 pillaries with which the ovisac is furnished, 

 and which, long before the vesicle has attained 

 its full diameter, appear in the form of a rich 

 network upon its inner surface, giving to the 

 latter a bright red colour. 



And now a thickening of the walls of the 

 follicle becomes very manifest, accompanied 

 by an exudation of blood which collects in the 

 interior of the sac. The period at which this 

 escape of blood commences is variable. Some- 

 times it may be seen in follicles of not more 

 than \'" diameter, but more frequently when 

 they have attained a size of about 3'". 



As this exudation of blood takes place at a 

 period certainly antecedent to the rupture of 

 the follicle, it cannot be traced to vessels 

 lacerated during that process, but must pro- 

 ceed from the congested capillaries just de- 

 scribed. It resembles arterial blood, and is 

 rich in globules, which at first remain free and 

 distinct ; but when the distension of the fol- 

 licle has become considerable, the blood co- 

 agulates into a dark-red clot. 



This pouring-out of blood has been termed 

 the menstruation of the follicle ; but beyond 

 the purpose of increasing the distension of 

 the latter, preparatory to its rupture, no use 

 has been assigned to it, except by Pouchet, 

 who maintains that in the sow the ovum lies 

 at the bottom of the follicle, instead of near 

 its upper or free surface ; and that as the 

 sanguineous exudation increases, it collects 

 between the inner surface of the ovisac and 

 the membrana granulosa, and so carries up- 

 wards the latter, together with the ovum which 

 is lodged upon it. He asserts, further, that 

 in proportion as this exudation increases, the 

 albuminous fluid previously occupying the 

 follicle is absorbed, until the entire cavity be- 

 comes filled with blood. 



The result of this process is, that the ovum, 

 previously lying at the bottom, is now trans- 

 ported to the upper part of the follicle, imme- 

 diately beneath the point at which the rupture 

 of the walls is about to take place. 



Notwithstanding the minuteness of Pou- 

 chet's description, its accuracy, so far at least 

 as concerns the supposed purpose of this exu- 

 dation of blood, has been called in question. 

 The fact, however, cannot be disputed, that, 

 in many animals, as well as in man, the follicle 

 does contain blood, often in considerable 

 quantity, previous to its rupture. And this is 

 a very important point, because it serves to 

 refute the statement of some who maintain 

 that the presence of blood, or of a clot, within 

 the follicle, affords certain evidence that the 

 rupture of the latter, together probably with 

 the escape of the ovum, has already occurred. 

 Barry also, in his researches upon the rabbit, 

 says, that after certain of the ovisacs have 

 discharged their ova, "some of the larger 

 Graafian vesicles, remaining unbroken, are fre- 

 quently found to contain a considerable quan- 

 tity of blood. Such spots, he observes, have 



been noticed by several observers, who sup- 

 posed them to indicate the Graafian vesicles 

 from which ova were destined to be expelled. 

 Thus Barry's prior testimony serves to 

 confirm that of Pouchet and others, to the 

 effect that the blood found within the follicle 

 does not result from its rupture, but that it is 

 there antecedent to that process. 



Some other changes which occur in the 

 follicle previous to its rupture may here be 

 noticed. The thickening just spoken of takes 

 place in the inner membrane, or that which 

 constituted originally the ovisac. This thick- 

 ening is sometimes so considerable as to in- 

 crease the diameter of the follicular walls to 

 three times their original amount. At the 

 same time, their contour becomes somewhat 

 undulating, and their colour approximates to 

 that of the buffy coat of the blood. 



While these changes are going on in the 

 substances and in the contents of the follicle, 

 preparation is being made externally for the 

 rupture at a certain part of the parietes. The 

 base of the follicle continues to be imbedded 

 in the substance of the ovary (Jig. 379.), but 

 the upper portion projects free above this, 

 being covered only by the usual ovarian in- 

 vestments. Here, at the more salient portion 

 of the projecting vesicle (Jig. 379.), an in- 

 creased vascularity is observable. The peri- 

 toneum and sublying tissues become exceed- 

 ingly red, and an abundance of blood is observed 

 in the numerous capillaries which are now 

 visible upon the summit of the vesicle. After 

 this, the fibres of the ovarian coverings become 

 gradually separated, preparatory to their com- 

 plete laceration. The tunics also of the fol- 

 licle itself become perceptibly thinner at this 

 spot, which corresponds with the situation of 

 the ovum always, at this period, lying im- 

 mediately beneath it. 



Fig. 379. 



Portion of ovary of the sow. The follicles are in a 

 more advanced stat/e titan infiy. 378. Two of these 

 are preparing for rupture. Already a small aper- 

 ture is perceptible in the centre, immediately above 

 the spot where the ovum lies; and towards this point 

 the bloodvessels converge. (After Pouchet.) 



The same regular sequence of changes, 

 which may always be traced in the Mammalia, 

 though with some slight variations according 

 to species, occurs also in man. If the exami- 

 nation be made in a young and previously 

 healthy woman, who has menstruated regularly 

 up to the time of her death, there will gene- 



