46 THE VETERINARY SCIENCE. 



made up of small glands and tubes — the glands secrete the milk 

 from the blood, while the tubes retain or hold the milk until it is 

 drawn away from the bag either by milking or the young animal 

 sucking During the time of suckling the young, the glands are 

 largely supplied with blood, from which the milk is secreted. 

 On the under side of each gland is found the teat, or the part 

 the young animal takes hold of in sucking. The end of the teat 

 is pierced by several small holes, where the milk comes out. 



THE FOETUS, OR YOUNG ANIMAL BEFORE BIRTH. 



In considering this we must first speak of the ovum, or egg, 

 which is secreted by the ovary of the mare. Every time she comes 

 in season (which occurs every three weeks during the hot weather) 

 this ovum, or egg, passes down the tubes before mentioned into the 

 womb, where it remains a few days and then dies if she is not put to 

 the horse ; but, if during the time this ovum is in the womb she is 

 put to the horse and one of the little bodies which is found in the 

 semen of the horse comes in contact with it the ovum and this 

 little body unites together, the rest of the semen dies and passes 

 away, while the neck of the womb gradually contracts until it is 

 perfectly tight. These two little bodies begin to grow when 

 united and forms the fcelus, or foal. The three parts connected 

 with the foetus, are the foetus, navel string, and cleanings, 

 or placenta The cleaning, or placenta, is the part which is found 

 covering the foal and is attached to the little pea-like elevations 

 on the inside of the womb. This covering is found to be full of 

 small blood vessels which run to one point where they unite 

 to form two larger vessels, known as the navel veins, which carry 

 the blood up through the navel opening of the foal where it passes 

 up to its heart ; by the action of the heart it is forced out all 

 through the body of the foal and returned to the heart and then 

 forced down another artery which passes it down to the navel 

 opening, along the navel cord, into the cleaning or placenta 

 again, where it is distributed through the small blood vessels. As 

 the blood comes down this cord from the foal it is in its impure 

 state, and while it is passing through these small vessels in the 

 cleaning it comes very close to the small blood vessels in the 

 womb. The blood is cleansed and nourished from the blood of its 

 mother by a process similar to that which was spoken of in con- 

 nection with the lungs. The foetus, or foal, does not grow so fast 

 the first month as it does later on ; at the age of seventeen weeks 



