PROFESSOR TURNER ON THE PLACENTATION OF THE SLOTHS. 95 
of the rabbit, but through the non-placental portions of the mucosa in the 
gravid uterus, which have been carefully prepared by Mr Sriruine, and, from 
the appearances presented by these sections, there is, I think, good reason to 
regard these “glandular follicles” as only utricular glands somewhat modi- 
fied in their shape. For though the part which lies next the uterine cavity has 
not the cylindrical-tubular form usually exhibited by the utricular glands, the 
deeper extremities of these follicles lying next the submucosa present, on trans- 
verse section, a circular or oval form, and on longitudinal section an elongated 
tubular form, such as the utricular glands themselves exhibit. Moreover, both 
the dilated and tubular portions of the so-called follicles are lined by a columnar 
epithelium, which projects into their cavity, but leaves a central lumen. It is 
clear, therefore, that these follicles or glands exist in the uterine mucosa prior 
to impregnation, and are not occasioned by the gravid condition. 
The very important observations recently made by M. AtpHonse MILNE- 
Epwarps* on the placentation of the Lemurs, furnish some material for com- 
paring this group of animals with the sloths. M. Epwarps has examined 
specimens of the genera Propithecus, Lepilemur, Hapalemur, and Chirogaleus. 
He found the chorion almost entirely covered by dense, compact villosities con- 
stituting a sort of vascular cushion, the result of the confluence of a multi- 
tude of: irregular cotyledons. The placenta had the appearance of a large sac 
which almost completely enclosed as in a hood the amnion. ‘This form of pla- 
centa he calls bell-like (placenta en cloche), for the villi are most numerous at the 
upper and middle parts of the chorion, but almost entirely disappear towards the 
cephalic pole. The uterine mucosa corresponding to the villosities exhibited 
numerous irregular anfractuosities, and had developed a caducous layer. An 
enormous sac-like allantois was situated between the chorion and amnion. In 
its general mode of disposition on the chorion, the placenta of the lemur is not 
unlike that of the sloth, but in the latter animal the lobes or cotyledons are 
apparently less intimately blended than in the former, which has in addition a 
highly-developed allantois ; but as no information is given on the arrangement 
of the utricular glands or maternal blood-vessels, I can make no comparison 
between the disposition of these important structures inthe Lemurs and Sloths.t 
* Annales des Sciences Naturelles, xv., 1871. 
+ Since this Memoir has been put in type my attention has been directed by Prof. Ry O. 
CunnineHam to a paper “On the Lemurs,” by Mr St Geores Mivart, in Proc. Zool, Soc. London, 
May 20th, 1873. Mr Mrvarr states that from a private communication made to him by M. 
AtpHonse Mitne-Epwarps, that naturalist is now of opinion that the Lemuroids have no decidua, 
and that the placenta is diffuse. It does not appear from Mr Mivarv’s paper whether M, Mitnn- 
Epwarps had received additional specimens since the publication of his Memoir quoted in the text, in 
which, when describing the uterine mucosa of Propithecus, he says, “ Et la surface en est hypertrophiée 
de fagon & former une couche caduque, trés-analogue & celle qui, dans une trés-faible étendue, adhere au 
placenta discoide des Singes, des Insectivores et des Rongeurs.” From which extract it is clear that 
when his Memoir was written, M. Minnz-Epwarps had no doubt of the presence of a decidua. 
VOL. XXVII. PART I. 28 

