THE FEMALE GENERA TIVE APPARA TUS. 



177 



The blood-vessels of the ovary pass, as we mentioned above, 

 from the hilus into the medullary substance. They at once 

 acquire such a development that the connective tissue forms 

 a relatively scanty connecting substance. The outer surfaces 

 of the veins coalesce with the latter tissue. The spindle cells 

 of the connective tissue must be muscular, for the ovary is 

 contractile (His, Frey). From the medulla numerous and 

 elegant vascular expansions pass between the follicles of the 

 cortex, circumvoluting them with the already described net- 

 work. The cortical zone, alone, is very poor in blood-vessels, 

 as we already know. 



A considerable wealth of lymphatics is also met with in the 

 medullary substance. A net-work of the same also circum- 

 volutes the follicles. 



The parovarium represents the remains of the embryonic 

 primitive kidney or the Wolffian body. It consists of con- 

 nective-tissue passages, lined with ciliated cells. 



The ovary also originated from this primitive kidney, and 

 the permanent ordinary kidney from the efferent canal of the 



e & .7 



Fig. 159. — The ovary of a human fetus of 32 weeks, in perpendicular section ; a, germinal epi- 

 thelium ; b, youngest ova cells (primordial ova) lying in this ; c, a growing connective-tissue trabe- 

 cula ; d, epithelial cells becoming buried ; e, youngest follicles ; /, ovum — and germinal epithelial 

 cells in groups : g, lymphoid cells. 



latter gland. Unfortunately, we cannot enter further into this 



subject. We merely mention that, according to Waldeyer, 



in the embryonic chicken, at an early period, at the inner side 

 8* 



