PROFESSOR TURNER ON THE PLACENTATION OF THE SLOTHS. 73 
safely admitted to exist.” Dr Ro.ieston on the other hand states,* that the 
figure of the placenta of the sloth which is given by C. G. Carus “does not 
seem to me to be so decidedly different from even the human placenta, in 
its naked-eye bossy outlines, as Dr SHARPEY’s account of the placenta of Manis 
shows it to be from the placenta of all the Carnivora, Rodentia, Insectivora, 
Chiroptera, and Simiadz which have been as yet examined. A well injected 
or even well preserved pregnant uterus of a sloth, would be most valuable, 
and would enable me to speak more confidently as to the extent of intimacy 
with which the maternal and foetal blood-vessels are connected than the figures 
from Professor Carus’s work can do.” 
Lastly, those systematic zoologists who, like Professors Vicror Carust 
and E. HA&rcKEL,{ have adopted the placental system of classification, have 
placed the sloths as members of the Edentate order amongst the Indeciduata. 
In this memoir, I hope to clear up the obscurity which has hitherto sur- 
rounded this subject, to place on a more precise and definite basis our know- 
ledge, not only of the condition of the gravid uterus and the arrangement of 
the foetal membranes in the sloths, but of the form of the placenta, its naked 
eye, and, so far as the examination of a single specimen can enable one, its 
microscopic structure; and to throw some additional light on the zoological 
affinities of this interesting group of mammals. 
Uterus and Placenta. 
On March 4th of the present year, I had the good fortune to receive the 
perfectly fresh carcase of a female two-toed sloth. I am indebted to my former 
pupil Dr Davin Rippats, Surgeon in the West India Mail Packet Service, for 
this valuable specimen, which he procured alive at Colon on the Atlantic side 
of the Isthmus of Panama. It died only two days before reaching England. 
Dr Rippats packed the carcase in salt, placed it in the ice-chest, and forwarded 
it to me immediately on landing.§ The subsequent dissection revealed it to 
be the species of two-toed sloth which possesses only six cervical vertebre, 
and to which Professor PETErs has given the name Cholepus Hoffmanni.|| 
I lost no time in cutting into the abdominal cavity, and to my great gratifi- 
cation saw that the uterus was obviously in the gravid condition. It occupied 
not only the pelvis, but the adjacent part of the abdominal cavity; and it 
overlay the kidneys, and had pushed the coils of the intestine forwards and to 
* Trans. Zoological Soc. vol. v. p. 303. 1863. 
+ Handbuch der Zoologie. Band I. 65. Leipzig, 1868. 
{ Natiirliche Schépfung’s Geschichte. Berlin, 1868. 
§ I wish to take this opportunity of thanking Dr Ripparu not only for the above specimen, 
but for a number of other valuable zoological objects from Central America which he has from 
time to time presented to the Anatomical Museum of the University. 
|| Monats, Berichte Berlin Akad. 1858, p. 128, and 1864, p. 679; and Natural History Review, 
vol. v. p. 299. 1865. 
