EMBRYOLOGY. 



Reproduction is the function by which the species is preserved ; 

 it is accomplished by the organs of generation in the two sexes. 

 Embryology is the science which investigates the successive stages 

 in the development of the embryo. 



GENERATIVE ORGANS OF THE FEMALE. 



The generative organs of the female consist of the ovaries, 

 Fallopian tubes, uterus, and vagina. 



The ovaries are two small, ovoid, flattened bodies, measuring i% 

 inches in length and % of an inch in width ; they are situated in the 

 cavity of the pelvis, and are imbedded in the posterior layer of the 

 broad ligament ; attached to the uterus by a round ligament, and to 

 the extremities of the Fallopian tubes by the fimbrise. The ovary 

 Consists of an external membrane of fibrous tissue, the cortical 

 portion, in which are embedded the Graafian vesicles, and an internal 

 portion, the stroma, containing blood-vessels. 



The Graafian vesicles are exceedingly numerous, but are situated 

 only in the cortical portion. Although the ovary contains the 

 vesicles from the period of birth, it is only at puberty that they attain 

 their full development. From this time onward to the catamenial 

 period there is a constant growth and maturation of the Graafian 

 vesicles. They consist of an external investment, composed of fibrous 

 tissues and blood-vessels, in the interior of which is a layer of cells 

 forming the membrana granulosa ; at its lower portion there is an 

 accumulation of cells, the proligerous disc, in which the ovum is 

 contained. The cavity of the vesicle contains a slightly yellowish 

 alkaline, albuminous fluid. 



The ovum is a globular body, measuring about T i ? of an inch 

 in diameter ; it consists of an external investing membrane, the 

 vitelline membrane; a central granular substance, the vitellus, or 

 yolk; a nucleus, the germinal vesicle, in the interior of which is 

 imbedded the nucleolus, or germinal spot. 



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