[ 569 ] 
XXII. On the Placentation of the Lemurs. By William Turner, M.B. {Bond.), Pro- 
fessor of Anatomy in the University of Edinburgh. Communicated by Professor 
Huxley, Sec.B.S. 
Received February 21, — Read March 30, 1876. 
Contents. 
Page 
Introduction 569 
Gravid uterus of Projoithecus cliadema 571 
Gravid uterus of Lemur rufipes 574 
Gravid uterus of Indris brevicaudatus 578 
General Observations on the Placentation of the Lemurs 579 
Prior to the year 1871 naturalists were unacquainted with the form and structure of 
the placenta in the Lemurs. On the 14th August of that year M. Alphonse Milne- 
Edwards communicated to the Academy of Sciences of Paris a short memoir, entitled 
“ Observations sur quelques points de l’Emhryologie des Lemuriens, et sur les affinites 
zoologiques de ces animaux”*. In this memoir M. Milne-Edwards stated that he had 
examined gravid uteri of Lemurs belonging to the genera Propithecus, Lepilemur , Papa- 
lemur, and Cliirogaleus with the following results. The chorion was almost entirely 
covered by villi, compactly arranged, constituting a kind of vascular cushion, and form- 
ing a placenta which enveloped, as with a hood, almost completely the amnion. He 
named the placenta u placenta en cloche or bell-shaped placenta. The villi were 
very bushy in the upper and mid portions of the ovum, and diminished gradually as 
they approached what he terms the cephalic pole, where they disappeared over a surface 
of some extent. The caduca uterina was very developed, and presented a corresponding 
disposition. He found a large sac between the chorion and amnion, which he regarded 
as the umbilical vesicle. He concluded that the placenta was constructed on a distinct 
type from that of all other mammals, but was further removed from that of Man, Apes, 
Bats, Insectivores, and Eodents than from that of the Carnivora, — “car si l’on suppose un 
instant le pole caudal de l’ceuf du chien envahi par les villosites du placenta, on a 
presque la realisation des caracteres speciaux a l’ceuf des Lemuriens.” 
In October of the same year M. Milne-Edwards reproduced this memoirf, but with 
some important additions and modifications. In Propithecus, he said, the vascular 
cushion formed by the villi resulted from the confluence of a multitude of irregular 
cotyledons. The middle and upper portions of the mucous membrane exhibited numerous 
* Comptes Rendus, 14 Aout, 1871, p. 422. 
t Annales des Sciences Naturelles, October 1871. 
4 K 
MDCCCLXXVI. 
