272 GENERATION. 



live tissue, with smooth muscular fibres. The blood-vessels, 

 which penetrate at the hilum, are large and convoluted, espe- 

 cially at the hilum itself, where there is a mass of convoluted 

 veins, forming a sort of vascular bulb, which has been de- 

 scribed particularly by Rouget. In the medullary portion 

 of the ovary, which is sometimes called the vascular zone, 

 the muscular fibres follow the vessels, in the form of muscu- 

 lar sheaths. According to Rouget, the mass of vessels at the 

 hilum constitutes a true erectile organ. 1 



In addition to the blood-vessels, the ovary receives nerves 

 from the spermatic plexus of the sympathetic, the exact mode 

 of termination of which has not been ascertained. Lym- 

 phatics have also been demonstrated at the hilum. 



Graafian Follicles. These vesicles, or follicles, were de- 

 scribed and figured by De Graaf, and are known by his 

 name. 3 They contain the ova, undergo a series of interest- 

 ing changes, enlarge, approach the surface of the ovary, and 

 finally are ruptured, discharging their contents into the fim- 

 briated extremity of the Fallopian tube. 



It was formerly supposed that the smallest Graafian folli- 

 cles were situated deeply in the medullary portion of the 

 ovaries, approaching the surface gradually, as they became 

 larger ; but it is now known that they are developed exclu- 

 sively in the cortical substance. If, indeed, we examine the 

 ovary at any period of life, we find no follicles properly in 

 the medullary substance ; but a few of the larger may pro- 

 ject downward, so as to encroach somewhat upon it, being 

 actually of a diameter greater than the thickness of the cortex. 



The earlier anatomists supposed that the Graafian folli- 

 cles were few in number, fifteen or twenty, but they counted 

 those only that were readily seen with the naked eye. "When, 

 however, it was calculated that ova might be discharged 



1 ROUGET, Recherches sur les organes erectiles de la femme. Journal de la 

 physiologic, Paris, 1858, tome i., p. 320, et seq. 



2 REGNERUS DE GRAAF, De Mulierum Organis Generationi inservientibus Trac- 

 tate Novus, Lugd. Batav., 1672, p. 190. 



