REPRODUCTION. 177 



fluid which the nucleus contains, there is a small dark, almost 

 opaque spot, the germinal spot of the ovum. 



Do all the Graafian follicles develop ova ? 



No. From puberty to the menopause the formation of new 

 Graafian follicles is continuous, and a very great number are pro- 

 duced, but many do not develop ova, and so waste away without 

 going through the changes described. 



Describe the Fallopian tubes. 



These tubes are about 3 inches in length, and extend from the 

 fundus of the uterus laterally on each side. The calibre of the 

 tubes gradually narrows from without inward, until at the uterus 

 the opening is very minute. The external covering is peritoneum, 

 but the lining is of mucous membrane, having ciliated epithelium. 

 The outer end of the Fallopian tube is free and fringed the fimbri- 

 ated extremity. 



What is the function of the fimbriated end of the Fallopian 



tube? 



To grasp the ovary during sexual excitement and prevent the 

 escape of an ovum which may extrude the " morsus diaboli." 



What is the use of the ciliated epithelium ? 



To carry the ovum to the uterus. This is also accomplished by 

 the action of the circular and longitudinal muscular fibres. 



Describe the uterus. . 



It is a somewhat pear-shaped organ, and is about 3 in. in length, 

 its wider part being about 2 in. wide and the cervix 1 in. It is 

 described as consisting of a fundus, body, and cervix. The body 

 unites the fundus with the cervix, which extends into the vagina. 



What structures compose the uterus? 



It is covered over nearly all of its external surface by (1) peri- 

 toneum. Its bulk is made up of unstriped (2) muscle, which oc- 

 curs in longitudnal and circular bundles and layers. This muscu- 

 lar tissue increases enormously during pregnancy, and by its 

 strength helps to extrude the foetus. The lining is of (3) mucous 

 membrane, which is formed in its superficial layer of ciliated 

 columnar epithelium. In the mucous membrane of the cervix are 

 a number of follicles which secrete a viscid, tenacious mucus, by 

 which the os uteri is frequently found to be plugged. 



12 Phy. 



