552 



UTERUS AND ITS APPENDAGES. 



from their supposed office in suspending the 

 ovum, and retaining it in its proper situation 

 in the Graafian follicle. 



That the retinae ula, however, are not essen- 

 tial structures is proved by the fact that they 

 are wanting in many of the Mammalia as well as 

 in Man. They have been observed chiefly in 

 the Rodentia and Ruminantia, where their form 

 and number are subject to considerable varia- 

 tion. The subjoined figure exhibits the ovum 



Fie. 376. 



Ovum of rabbit surrounded by the tunica granulosa 

 and portions of retinacula. {After Coste.) 



surrounded by the layer of granules which 

 constitutes the tunica granulosa, and externally 

 to this the radiating bands or retinacula, the 

 whole of those parts, external to the ovum, 

 being composed of nucleated cells. 



Besides these structures, the Graafian follicle 

 contains a pellucid albuminous fluid, of a 

 slightly yellowish colour, partially coagulable 

 by heat. In this fluid float numerous granules 

 similar to those of which the parts just de- 

 scribed are formed, together with a varying 

 quantity of oil-like globules. 



Lastly, in the midst of the granules at an 

 early period, and subsequently in that more de- 

 finite arrangement of them which constitutes 

 the tunica granulosa, is contained the ovum 

 (/g. 374. /, and Jig. 376.), a full description 

 of which is given in the article under that title. 



4. Vessels and Nerves. The ovary de- 

 rives its supply of blood chiefly from the 

 ovarian (spermatic), but in part also from the 

 uterine arteries. So free, indeed, is the com- 

 munication between these vessels, that the 

 organ may be equally well injected from either 

 source. The communication is effected chiefly 

 by means of a branch of the ovarian artery, 

 which passes inwards to inosculate with a ter- 

 minal branch of the uterine artery, this anas- 

 tomotic branch being occasionally so large as 

 to constitute the principal source of supply of 

 the ovary. The terminal vessels are con- 



ducted to the lower border of the ovary be- 

 tween the folds of the posterior duplicature 

 of the broad ligament, where they lie in 

 parallel lines, and are readily distinguished by 

 their tortuous or spiral form. Having en- 

 tered the base of the organ, they spread out 

 into those numerous ramifications which pene- 

 trate every part of the ovarian stroma, and 

 give to this structure its peculiar fibrous as- 

 pect. From their extreme branches the blood 

 is returned by the veins, which pass to the base 

 of the organ, where they are very numerous 

 (fig. 370. h). They form, near the ovary and 

 between the folds of the broad ligament, a 

 plexus termed the ovarian or pampiniform 

 plexus, (Jig. 369. d) the vessels of which com- 

 municate also with the uterine plexus. 

 Valves are found in the ovarian veins only 

 in exceptional cases. 



The ovary derives its nerves from the renal 

 and inferior aortic plexuses.* The nerves 

 enter the organ along with the blood-vessels. 



FUNCTIONS OF THE OVARY. 



The ovary is to the female what the testis is to 

 the male the germ-preparing organ, the part in 

 which is formed the female generative element, 

 and therefore the essential portion of the entire 

 sexual apparatus. To it all other structures 

 may be regarded as accessory or superadded ; 

 for in by far the largest proportion of the 

 animal kingdom they are either found in a 

 rudimentary state, or else have no existence. 

 But not only is the ovary the organ in which 

 the formation and evolution of the germ take 

 place ; its offices farther extend to the separa- 

 tion and expulsion of the ova, when they 

 have reached such a state of maturity as will 

 render them susceptible of impregnation. 

 This process, commonly termed ovulation, 

 takes place spontaneously, and without the 

 intervention of the male, which is not neces- 

 sary thereto. All animals possessing an ovary 

 are subject to this law ; and Man constitutes 

 no exception to the rule. But the functions 

 of the ovary are exercised only during a cer- 

 tain period of life. The ova, which are formed 

 at or near the time of birth, and sometimes 

 before that event, are not called into activity 

 until the body of the parent is sufficiently 

 developed, to suffer the parturient act without 

 destruction or serious detriment to its own 

 tissues, such as would be incompatible with 

 the continuance of its own life, and such as is 

 witnessed in those lower tribes where the 

 whole of the vital energies of the parent are 

 exhausted by one effort of reproduction, or 

 its tissues are even disrupted by the process 

 which produces its kind. But long before the 

 time arrives at which the generative faculty is 

 capable of being fully exercised, it is probable 

 that many of trie ova which were first formed 

 have perished, their place being continually 

 supplied by new formations.-f- Their numbers, 

 however, are so great that, if only the one 

 thousandth part of those originally contained 



* Snow Beck, Phil. Trans. 1846, part ii. 

 t Barry, Phil. Trans. 1838, part ii. p. 319. Dr. 

 Ritchie, fifed. Gaz., vols. xxxiii., xxxiv. 



