4 BOVINE OBSTETRICS 



empties, a cavity should be formed. Such is actually the 

 case, but it is filled immediately with blood from the vessels 

 in its wall. It is a hemorrhage per rhexin. The blood 

 coagulates, the site of rupture closes, and the coagulum 

 becomes incarcerated. The inner lining of the Graafian 

 follicle granulates and forms a number of young connective 

 tissue cells in the coagulum. The greater part of the 

 coagulum is absorbed and replaced by young connective 

 tissue. The remaining pigment causes a yellow or orange 

 tinge of the connective tissue mass, for which reason the 

 body replacing the Graafian follicle is termed "yellow 

 body" (corpus luteum). When impregnation follows, and 

 thus the periodical hypersemia of the ovum ceases, regres- 

 sion of the corpus luteum is manifested, yet it can be 

 recognized shortly before gestation ends. When fecunda- 

 tion does not take place and periodical ovarian hypersemia 

 . appears every three weeks, the coagulum is absorbed and 

 a little scar tissue forms. The hypersemic condition of the 

 genital apparatus is looked upon as a reflex act, induced by 

 the pressure of the Graafian follicle upon nerve endiugs 

 causing an irritation of the vaso-dilators. This congested 

 state causes a mucoid fluid, containing many leucocytes and 

 fat globules, to be thrown ofl by the mucosa of the Fallopian 

 tube. In this liquid the fecundated egg rests. (Franck.) 



CONCEPTION. 



During coition the penis in all probability enters the 

 cervical canal, and the semen is poured into the uterine 

 cavity. The spermatozoa may reach the egg either by their 

 own movement or the antiperistalsis of the uterus and tubes. 

 At the moment of ejaculation and already previously the 

 uterus contracts, thus narrowing its lumen. Later the uterine 

 muscle relaxes, a negative pressure, and aspiration of the 

 semen follows, which is now carried to the oviduct by the 

 factors already enumerated. 



This is a rather rapid process, as one hour after coition 

 spermatozoa can be detected in the Fallopian tube (Franck), 



