: 38 VETERINARY OBSTETRICS. 
irregularly distributed, being very numerous, especially 
about the horns, while at other situations they may be 
absent. 
In the Bitch, the vascular connection has been 
termed ‘‘zonular.” The tufts are arranged in a ring or 
circle around the external aspect of the chorion, 
contacting a similar circle on the internal aspect of the 
uterus. This zone or circle is from one and a half to 
two inches broad. 
In animals which give birth to more than one fcetus. 
at a time, each foetus may have a separate chorion and 
umbilical cord complete, and in this case that portion 
of the chorion which is in contact with another 
chorion, and not in contact with the wall of the uterus, 
has no vascular tufts. In other cases, there is one 
common chorion, and from it each foetus is supplied 
with an umbilical cord, through which it derives its. 
nourishment. ‘ 
Umbilical Cord. 
This forms the means of communication between 
the parent and fcetus. 
In the Mare, besides the tissue proper of the cord, 
it consists of two arteries and one vein. The arteries. 
are given off by the internal iliacs of the foetus, pass. 
along the lateral aspect of the bladder, and leave 
the abdomen (of the foetus) at the umbilical opening. 
They then give off some small nutrient branches to. 
the structure of the cord, pass outward, and break up. 
into a great number of smaller vessels, which ramify 
between the external surface of the allantoid membrane 
