« 
FCETUS. 
of the mother and child ; and of the preg- 
nant uterus itself, since the peculiarities 
distinguishing its structure at this time arise 
from the residence of the foetus in its cavity. 
The following description applies to the 
uterus and its contents in the ninth month 
of gestation. The size of the organ differs 
much in different individuals ; and this arises 
principally from varieties in the quantify of 
the liquor amnii. In shape it is oviform ; 
the fundus answering to the largest extre- 
mity of the egg, and the cervix and os uteri 
to the small end. It deviates from this re- 
gular figure from various accidental causes, 
as it adapts itself to the neighbouring parts, 
to the attitude of the body, and to the posi- 
tion of the contained child. Parts of the 
latter can often be distinguished in the living 
state. The small, or lower end of the ute- 
rus, is placed in the pelvis ; this contains the 
greater part of the child's head, and fills up 
the cavity so completely as to press the 
bladder against the pubes, and the rectum 
against the sacrum. The body and fundus 
of the uterus, containing all the rest of the 
child and the placenta, is placed in tiie 
front of the abdomen, from the pelvis up- 
wards to the epigastric region, so as to be 
under and before all the other bowels. It 
occupies the whole space from one hip-bone 
to the other. 
The round ligaments, Fallopian tubes, and 
ovaria, necessarily undergo considerable 
change in their situation: they become 
closely connected to the uterus, as that 
body in its enlargement extends between 
the two layers of the broad ligaments. The 
ovaria are particularly distinguished after 
conception by containing a corpus luteum. 
This is a firm, fleshy portion, distinguished 
by its yellowish grey colour from the rest of 
the ovary, and considered as a certain proof 
that conception has taken place. If there 
is one child there is only one corpus lute- 
urn ; if two children, two of these bodies, 
"&c. The thickness of the pregnant uterus 
is from one to two-thirds of an inch. The 
arteries and veins of the uterus are wonder- 
fully increased in size in the pregnant state, 
particularly opposite to the attachment of 
the placenta. This change seems to arise 
naturally from the important office which 
the vessels have to perform at this period ; 
viz. the developement and nutrition of the 
foetus. Anatomists have disputed concern- 
ing the muscularity of the uterus ; but Dr. 
Hunter describes the appearance of the 
muscular fibres, which are however very 
faint. The mouth of the uterus is closed, 
until the time of labour, by a viscid gluti- 
nous substance. 
The contents of the pregnant uterus are 
the secundines, liquor amnii, and the foetus. 
The former line the uterus, and immediately 
cover the child; they form the chain of 
connexion and communication between the 
bodies of the mother and child, and carry 
on that wonderful influence upon which the 
life and health of the child depend. They 
are divided into navel-string, placenta, and 
membranes ; and, as they are expelled from 
the uterus after the birth of the child, they 
are called the after-birth. 
The navel-string is a cord about two feet 
long, made of three vessels twisted toge- 
ther, and fixed at one end to the child’s na- 
vel, at the other to the placenta. Its ves- 
sels are an umbilical vein and two arteries : 
the latter carry blood from the child to the 
placenta, and the former brings it back 
again. 
Placenta. This, with the membranes, 
makes a complete bag, lining the uterus, and 
containing the child. It is thick, fleshy, and 
exceedingly vascular. Its figure is round 
and flat ; about an inch thick, and a span 
in breadth. The outer surface, which ad- 
heres to the womb, is rough, tender, and 
bloody; the inner is smooth, harder, and 
marked by the ramifications of the vessels 
proceeding from the umbilical cord, which 
is attached to this part. Its substance con- 
sists of two parts intimately blended; viz. 
an umbilical, or infantine, and an uterine 
portion. The former is a continuation of 
the umbilical vessels of the foetus, the latter 
an efflorescence of the internal surface of 
the uterus. The foetal portion, which is by 
far the largest part, is a regular ramification 
of the arteries and veins of the navel-string 
into smaller and smaller branches. No 
communication whatever has been disco- 
vered between these vessels and those of 
the uterus; so that the mode in which the 
foetus derives its nourishment and growth 
must be completely hidden from us. 
The uterine portion of the placenta co- 
vers its convex surface in the form of a thin 
membrane, and detaches innumerable fine 
processes into the substance of the part. 
It seems to be a portion of the decidua. It 
is connected into one mass with the umbili- 
cal portion, and the vessels of the uterus 
are continued into it, although they have no 
discoverable communication with the um- 
bilical arteries and veins. 
amnion, chorion, and decidua. 
N 2 
