80 HEALTH AND DISEASE 



tuting the greater part of the contents of the cell. Embedded in the yolk, 

 generally near the circumference, is a large spherical nucleus, the "germinal 

 vesicle ", within which is a nucleolus or " germinal spot ". When fully 

 developed, or ripe, the Graafian follicles. project from the surface of the 

 ovary, and sooner or later burst, at which time the ovum enters the 

 Fallopian tube and is conveyed to the uterus, where, if fertilized by the 

 male element, it develops into a foetus. Should fertilization not take 

 place then, the egg dies and undergoes disintegration. 



The small cavity in the substance of the ovary, from which the egg has 

 been discharged, becomes filled with blood, which ultimately disappears and 

 is succeeded by a small quantity of fibro-gelatinous matter, the " corpus 

 luteum ". 



Should pregnancy follow the discharge of the ovum, the corpus luteum 

 becomes much larger, and the changes occurring in it go on much more 

 slowly, so that it persists for a longer time. 



DISEASES OF THE ORGANS OF REPRODUCTION 

 OF THE HORSE 



The male organs of reproduction are not so frequently the seat of 

 disease as those of digestion or of respiration, but it should be remembered 

 that the comparative immunity enjoyed by our horses, employed both for 

 work and for pleasure, is largely due to the fact that geldings are chiefly 

 in use for the purposes named. 



The stud animal is liable both to disease and injury to an extent only 

 realized by those in intimate association with this class of horse. 



The artificial methods of feeding adopted by the generality of owners 

 of stallions renders their charges the more prone to inflammatory diseases, 

 and to this may be added the excitement and abuse incidental to the 

 service season, when each popular sire may be called upon to copulate 

 several times daily for a period of weeks. 



At rare intervals in this country, but not infrequently upon the con- 

 tinent of Europe, a malady prevails among breeding animals of a distinctly 

 contagious nature. It is known as maladie du coit, and is transmitted 

 from mare to horse and from horse to mare in the act of coition. 

 It sometimes becomes endemic, and may be the means of provoking 

 abortion. 



A specific bacillus of abortion has been made out by Bang with regard 

 to bovines, and it is more than probable that some such deleterious 

 organism will be discovered to affect the mare. 



While emasculation necessarily reduces the liability to disease in the 



