PROFESSOR W. TURNER ON THE PLACENTATION OP THE APES. 
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The umbilical cord contained one large vein and two arteries, with a small quantity 
of the gelatinous tissue of Wharton, but no trace of an allantois or umbilical vesicle 
could be seen. The umbilical vein after entering the abdomen ascended as an 
O 
undivided vessel as far as the under surface of the liver. The pair of umbilical 
arteries passed as the hypogastric arteries to the posterior wall of the abdomen. 
Between the hypogastric arteries was a fibrous cord, the obliterated urachus, which 
extended from the apex of the bladder to the umbilicus. The cord was invested by 
the amnion and the foetal surface of both the placental and non-placental parts of the 
chorion was lined, as in the human female, by this membrane. The surface of the 
amnion next the amniotic cavity was covered by a continuous layer of polygonal 
flattened epithelium cells, which were translucent and with faintly granulated proto- 
plasm, but with the nucleus relatively large and distinct. These cells rested on a thin 
layer of delicate connective tissue. 
The uterine ends of the Fallopian tubes opened at the sides of the uterus opposite 
the non-placental parts of the chorion situated between the two placentae. The cavity 
of the uterus communicated with the canal of the cervix at a well-defined os internum, 
the lip of which formed a projecting ring around the os. The cervical canal was about 
f inch long ; its mucous membrane was elevated into folds, some of which were vertical, 
but others were directed obliquely, so as to form an arrangement somewhat like the 
arbor vitae in the human cervix. The os externum was rounded and bounded by a 
distinct ring-like projecting lip. The vagina was If inch long ; its mucosa was partly 
smooth and partly thrown into sinuous rugae, some of which, near the os externum, 
were longitudinal, but the greater number were transverse. 
Structure of the wall of the Uterus. 
The wall of the uterus possessed an external serous coat as in the human female. The 
muscular coat was thin, and, relatively to the size of the uterus, much thinner than in 
the human uterus. In this respect the muscular coat resembled what is usually found 
in the mammalia where the impediments to parturition are not so great as in the 
human subject. 
The uterine cavity was lined by a well-marked mucous membrane, which formed a 
layer homologous with the decidua vera, or uterina of the human gravid uterus. In 
the region near the internal os, the chorion could be raised from the mucous membrane 
by gentle traction, without doing much injury to the free surface of the mucosa. 
This surface was not smooth, but presented numerous shallow ridges and furrows, 
which for the most part ran transversely to the long axis of the uterus. At the 
internal os, however, the ridges were vertical and were continuous with, though not 
so prominent as, the longitudinal columns of the mucosa in the canal of the cervix 
uteri. In the region of the fundus uteri, the adhesion between the non-placental part 
of the chorion and the surface of the mucous membrane was much more intimate than 
near the os internum; so that on raising the chorion it was usual to peel off flakes 
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