EMBRYOLOGY, IMPREGNATION, CONCEPTION. 39 



womb, the mouth of the womb is closed by a 

 plug of mucus. If from laceration or other 

 accidental cause the mouth is unduly distended 

 it will not be closed and the egg will pass out 

 into the vagina and be lost. Mares suffering 

 from any affection of the genital organs, such 

 as leucorrhea (whites), which sets up a dis- 

 charge from the mucous surfaces, will rarely 

 conceive. These discharges are acid and de- 

 stroy the spermatozoa. Similarly any condi- 

 tion such as a heavy cold, strangles or the like, 

 which induces high temperature or fever, will 

 operate to kill the sperm-cells. These, with the 

 germ of contagious abortion, are the commonest 

 causes of barrenness in mares. 



Any man reasonably intelligent can quickly 

 obtain a working knowledge of the genital or- 

 gans of the mare. Outwardly visible is the 

 vulva. This is the entrance to the vagina which 

 is a more or less cylindrical canal into which 

 the human hand may readily be passed with 

 the fingers placed so as to form a cone. A 

 short distance within the vagina will be found 

 a shallow depression on its floor and beyond 

 this a protuberance coming from beneath. On 

 no occasion or pretext should this be touched. 

 It is the meatus urinarius the orifice through 

 which the urine is voided from the bladder. 

 It is fitted with a valve and is a tender and 

 delicate structure. Mares have been killed by 

 ignorant operators mistaking it for the neck of 



