THE UROGENITAL SYSTEM 



423 



partially surrounds the ovary. The margin of this opening is prolonged 

 into numerous fimbriae which surround the ovary and convey the ova 



^rUNOUS UTERI 



NUCLEAR OIVrSION 



IMPLAfTTATlON 



-CORPUS UUTEUM 



UTERINE TUBE 



SPERMATOZOON 



OVULATION 



ST POLAR BODY STAGE 



UTERINE GLANDS 



Fig. 347. — Diagram illustrating the passage of the fertilized egg from the ovary to 

 the uterus. The ovum is a week in the tube and three days in the uterus before implan- 

 tation takes place. (Redrawn after Dickinson's "Sex Anatomy," Williams & Wilkins Co.) 



into the uterine tube. A ciliated columnar epithelium Hnes the tubes, 

 the cilia beating towards the uterus and carrying the ova in that direction. 



Fig. 348. — Diagram of uterus simplex. /, opening of Fallopian tube; g. uterine 

 glands; m, muscular layer (no attempt to indicate direction of fibres); tnu, mucosa; 

 o, early implanted ovum. (From Kingsley's "Comparative Anatomy of Vertebrates.") 



The number of cilia is greatly increased by the complex folding of the 

 lining of the tubes. It has long been a question how spermatozoa make 



