PROF. W. TURNER ON THE PLACENTATION OF THE LEMURS. 573 
were directed towards the surface of the mucosa, none was seen to open into a crypt. 
When the free surface of the membrane was examined with a magnifying-power of 
45 diameters, the glands were observed to lie for the most part obliquely beneath the 
crypts, but, instead of opening into them, they converged in considerable numbers 
towards the depressed smooth areas already described on the surface of the mucosa. 
Each area that was examined had several annular openings in it, which were the mouths 
of the glands, and through some of them a plug of epithelium could be seen to project. 
As the membrane in the smooth depressed areas of the mucosa of Lemur rufipes was 
more translucent than in Propithecus , and the relation of the glands to their openings 
was more distinctly seen in that genus, 1 shall give in the description of that animal a 
more detailed account of the arrangement. The vascularity of the gland-layer of the 
mucosa and of the smooth depressed areas was less than that of the crypts. 
When the uterus was opened into, the bag of the chorion, with its enclosures, was 
found free and quite unattached to the uterine surface ; the caudal end of the foetus 
was projecting through the os uteri, and the cephalic end was in the uterine fundus 
formed by the dilated left uterine cornu. The chorion and other membranes envelop- 
ing the caudal end of the foetus were torn away, so that the tail and hind limbs were 
exposed, but the chorion enclosing the head and thorax was entire. The free surface of 
the uninjured chorion was traversed by numbers of ridgelets, some of which were in 
parallel rows, whilst others had more of a reticulated arrangement. Sometimes the 
ridgelets were closely crowded together ; at other times they were separated by well- 
defined intervals. Although the separation of the chorion from the mucosa did not 
permit one to see the foetal placenta in position, yet there could be no doubt that the 
ridgelets had fitted into the sulci between the folds of the mucosa. When examined 
microscopically the ridgelets were seen to be divided into villi, the greater number of 
which were broad leaflets, though many were more filamentous and elongated in form. 
To some extent also smaller leaf-like and filamentous villi arose from the surface of the 
chorion between the ridgelets. An occasional irregular patch on the chorion free from 
villi and ridgelets was seen, which had undoubtedly been in apposition with the smoother 
depressed parts of the mucosa, and the villi on the rest of the chorion had fitted into 
the crypts in the mucous membrane. The chorion with its villi possessed the usual 
structure of this membrane. It consisted of connective tissue, with a layer of cells on 
the free surface. The torn state of the membrane prevented an injection from being 
passed into the umbilical vessels ; but there can be no doubt that the villi were highly 
vascular. In M. M ilne-Ed wards’s specimens of Propithecus the head of the foetus pre- 
sented to the os uteri and the cephalic end of the chorion was smooth in correspondence 
with the smooth surface of the mucosa surrounding the os ; whilst the opposite or caudal 
end was villous. In my specimen the caudal end of the foetus was the presenting part ; 
and though the chorion enveloping it was torn away, there can be no doubt that it had 
been free from villi, for the surface of the mucosa with which it had been in apposition 
was smooth and without crypts. The opposite or cephalic pole, again, was strongly 
