PROFESSOR W. TURNER ON THE PLACENTATION OF THE APES. 
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the uterine surface of the placenta as covered by a smooth continuous deciduous 
membrane, between which and the muscular coat were loose lamellae, the deeper of 
which consisted of cells with large nuclei and tapering ends. A number of large blood 
vessels were seen amidst these lamellae. The lamellated tissue represented the non- 
deciduous serotina. From the deciduous layer on the surface of the placenta processes 
of decidua passed into its substance. Rolleston obviously inclines to the view that 
the maternal vessels within the placenta formed a sinus system as in the human 
placenta. The foetal villi were arborescent. 
Signor Ercolani* has examined a placenta ot Gercopithecus sabceus which had 
been preserved in alcohol. As he could not find any essential difference between its 
structure and that of the human placenta, he did not think it necessary to describe it, 
but states that the intra-placental lacunae for the maternal blood are smaller than in 
the human placenta, and that manifest traces of decidua serotina are present on the 
uterine face of the organ, which are continued on to the foetal villi, for which they 
form an external membrane. 
Kondratowicz has recently described! the uterus of a species of Macacus, in the 
last stage of pregnancy, preserved in the Museum at Warsaw. As it was not 
practicable to inject the placenta he gives no account of its structure, but he relates 
some facts bearing on the structure of the decidua vera. He states that the uterine 
mucous membrane is thickened, and he recognises on it an epithelium, which is 
blended with the chorionic epithelium. Subjacent to the uterine epithelium is a 
finely fibrous connective tissue with spindle cells and opaque yellow clumps of pig- 
ment ; in the deeper layers the cells increase in number, become multipolar, and 
assume the character of large epithelial-like decidua cells. These cells, he says, seem 
to form the immediate boundaries of wide blood-containing spaces or canals. Deeper 
than these cells and next the muscular coat is a layer of delicate connective tissue, 
the trabeculae of which bound large spaces lined by an epithelium formed of short 
hexagonal cylinders, with large nuclei. He regards these spaces as the expanded 
deeper ends of the utricular glands, the ducts of which have become obliterated. No 
gland-like spaces were recognised in the tissue between the placenta and the muscular 
coat of the uterus. 
By the researches of the several investigators above referred to, observations on 
the form of the placenta in the Apes, on the presence of a decidua, on the absence ox 
the sac of the allantois, on the absence or rudimentary condition of the umbilical 
vesicle, and -on the arrangement of the amnion have gradually been accumulated. 
* Sul processo formativo della porzione glandulare o materna della placenta. Mem. dell’ Accad. delle 
Scienze di Bologna, 1870, p. 53. 
t His memoir, entitled “ Przyczynek do histologii ciezarncj macicy,” is in the Pamietnik Towarzystwa 
Lekarskiego, Warszawa, Zezzj't iii. 1875, p. 259. As this memoir is in Polish, I have been unable to 
read it in the original, hut owe my knowledge of its contents to an abstract by Hoyek in Hofmann and 
Schwalbe’s “ Jahresberichte,” 1876. 
