THE ANATOMY OF THE HORSE 
ff 
blood, from which the milk is secreted. On the under side of 
each gland is found the teat, or that part taken hold of by 
the young when sucking. The end of the teat is pierced by 
several small holes, through which the milk parses. 
III. — THE FOETUS, OR YOUNG ANIMAL BEFORE BIRTH. 
We must here 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 spermatozoa from the semen of the horse comes in 
contact with it (the ovum) and a union of these takes place, 
then the rest of the semen dies and passes away, and the 
neck of the womb contracts gradually until it is perfectly 
tight. These two little bodies begin to grow when united 
and form the foetus, or foal. The foetus may be for conveni- 
ence divided into three parts, viz : the foetus proper, the navel 
string, and the cleanings, or placenta. The cleanings, 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 finally unite to form two larger vessels, known 
as the navel veins. These carry the blood up through the 
navel opening of the foal and then to its heart. By the action 
of the heart it is forced all through the body of the foal and 
returned again to the heart. It is then forced down another 
artery to the navel opening, along the navel cord, into the 
cleaning or placenta again, where it is distributed through the 
small blood vessels. When 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 when speaking 
of 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 
the first hair appears on the lips and the tip of the tail. Be- 
tween the thirty-fifth and the fortieth week the foal begins 
to show signs of life, and is completely covered with hair. 
^iter this time it grows very rapidly and may be seen mov- 
1 
