REPRODUCTION AND DEVELOPMENT. 



Fig. 142. UTERUS of SHEEP. 

 a, a, The cornua. 



anterior and posterior walls in contact, and its three borders, 

 one above and one at each side, all bulging inwards. The 

 upper angles are distinguished as the cornua, being parts 

 which in many of the lower animals are greatly elongated, 

 so as to render the uterus completely forked. Into each 

 cornu opens a long narrow duct, the Fallopian tube, which 

 extends outwards in front of the ovary, and terminates im- 

 mediately beyond it in an expanded and fringed opening, the 

 fimbriated extremity, which leads from the peritoneal cavity, 

 and makes a communication 

 between it and the outside of 

 the body. In animals in which 

 the cornua are developed, they 

 are the parts which lodge the 

 young. Thus, in a sheep with 

 one lamb, the lamb occupies 

 one cornu; if there be twin 

 lambs, they lie one in each 

 cornu; and in animals which 

 have a litter of young, the em- 

 bryos are ranged in series in separate membranes along the 

 length of each cornu. 



204. The ovaries of persons who have died in the prime of 

 life present, scattered through their tough fibrous structure, 

 and more or less distinctly seen from the surface, a variable 

 number of clear vesicles, one or two of which may be like 

 very large beads immediately beneath the peritoneum. These 

 are called Graafian vesicles; each of them contains an ovum, 

 and gradually enlarging, and approaching the surface as it 

 enlarges, eventually ruptures and discharges its ovum, 

 covered with a coating of granules, the discus protigerus. 

 The ovum is caught up by the fimbriated extremity of the 

 Fallopian tube, which would appear to be applied to the 

 rupturing vesicle for that purpose. 



"While only a limited number of these vesicles are visible 

 with the naked eye, the microscope reveals others of minute 

 size in vast multitudes, which have been estimated at more 

 than 70,000 in one individual (Henle). The ova, more- 

 over, make their appearance prior to the vesicles which subse- 

 quently surround them, and already exist in large numbers 



