6 4 



THE WAY LIFE BEGINS 



The Ova and their History 



As the sperms are the smallest of all the cells of the body, 

 so the ova are the largest. The ova of man and the mammals, 

 however, may be seen by the naked eye when carefully 

 isolated. While there are a great many more ova produced 

 in the ovary (an oval body scarcely an inch in length) than 

 are used, there are still larger numbers of sperm cells produced. 



FIGURE 7 



The reproductive organs of the human female include the uterus (womb) I, the egg-tubes II, 



and the ovaries III. The uterus is supported by broad IV, and round V, ligaments. For 



a sectional view of these organs showing their relation to the other organs of the pelvis, 



see Fig. 8, page 65. 



The ripe egg discharged from the ovary is drawn into the egg-tube by the fine ciliated cells 



lining the tube and extending out on the finger-like processes at the tip of the tube. The 



egg passes on to the uterus where it lodges if it is fertilized. 



The powerful muscle fibres of the uterus, in contrast to those of the vagina VI, is indicated. 



For the appearance of the uterus during gestation, see Fig. 10, page 70. 



The sperm cells of the male are constantly being made during 

 the lifetime, but the ova of the female are all produced before 

 birth, and even, as we have seen, reduced in number after 

 birth. A process of growth of each individual ovum goes on 

 during the reproductive period in which a sheltering envelop, 

 the follicle, forms about it. Yolk is accumulated and the 

 nuclear material is reduced by half in preparation for the 

 union with the nuclear material of the sperm cell. This 



