590 



REPRODUCTION 



yolk, and is thus placed in the most favorable position for the action of 

 warmth and air in the development of the chick. 



In quadrupeds, the oviducts present a further modification. The egg, 

 which is originally of minute size, is retained within the generative 

 passages during the development of the embryo. While the upper 

 part of the oviduct, accordingly, is narrow, and serves merely to trans- 

 mit the egg from the ovary, and to supply it with a little albuminous 

 secretion, the lower portions are much enlarged, and adapted for the 

 protection and nourishment of the embryo. The upper and narrower 

 portions of the oviduct are known as the " Fallopian tubes," from Fal- 

 lopius* who first described them in the human female ; while the lower 

 and larger portions constitute the uterus. The two halves of the uterus 

 unite with each other on the median line near their inferior termination, 

 to form its "body;" while the ununited parts above are known as its 

 " cornua " or horns. 



In the human species, the ovaries consist of Graafian follicles, imbed- 

 ded in a somewhat dense connective tissue, supplied with blood-vessels, 



FIG. 164. 



UTERUS AND OVARIES OF THE Sow. a, a. Ovaries. 6, b. Fallopian tubes, c, c. Horns of the uterus. 

 d. Body of the uterus, e. Vagina. 



and covered with an opaque, yellowish-white layer of fibrous tissue, 

 called the " albugineous tunic." Its peritoneal layer is reflected in the 

 usual way upon the blood-vessels supplying the organ, and is con- 

 tinuous with the broad ligaments of the uterus ; but elsewhere it is 

 closely consolidated with the albugineous tunic. 



The oviducts commence by a wide expansion, with fringed edges, 

 called the "fimbriated extremity of the Fallopian tube." For most 

 of their length they are narrow and convoluted, terminating, on each 

 side, in the body of the uterus. This part of the organ is so much 

 developed at the expense of the cornua, that the latter hardly appear 

 to have an existence in the human species, and no trace of them is visi- 

 ble externally. But on opening the uterus, its cavity is seen to be 

 somewhat triangular in shape, its upper corners running out to join 

 the lower extremities of the Fallopian tubes. The cornua are therefore 



* Opera Omnia. Francofurti, 1600. Observations Anatomicse, p. 421. 



