582 
PROF. W. TURNER ON THE PLACENTATION OE THE LEMURS. 
the utricular glands in special areas dissociates their secretion from that of the crypts. 
The villi which fit into the crypts are the parts of the chorion which absorb their 
secretion; whilst the smooth, non-villous surfaces of the chorion opposite the smooth 
areas on the mucosa are engaged in the absorption of the secretion of the glands. 
As the placenta in the Lemurs has the arrangement and structure of a diffused pla- 
centa, it is presumably as non-deciduate as that of the other animals which possess the 
same form of placenta ; for in it, as in them, the foetal placenta can be separated from 
the maternal without carrying away a portion of the uterine mucous membrane. The 
demonstration, therefore, of the diffused and non-deciduate nature of the placenta in the 
Lemurs has an important bearing on the classification of these mammals. As it may 
be desirable to say a few words on this matter, I shall commence by a brief review of 
the opinions expressed by various zoologists of the position of the Lemurs in the class 
Mammalia. 
As is well known, Linnaeus constructed the order Primates to include Man, Apes, 
Lemurs, and Bats. Boddaert, in 1785, proposed the term Quadrimana for the Apes 
and Lemurs, as expressing the four-handed function of their limbs. Blumenbach, in 
1795, and Cuvier, shortly afterwards, separated the Apes and Lemurs from Man and 
the Bats, and made for them the distinct order Quadrumana ; and this arrangement, 
with some variations in the mode of subdivision of the order, has been adopted by 
Messrs. St.-Hilaire, Waterhouse, H. Milne-Edwards, Owen, Vrolik, Van der Hoeven, 
and Giebel. He Blainville preferred to retain the order Primates, in which he 
included the Apes and Lemurs ; and this arrangement, with some variations in the mode 
of subdivision of the order, has also been adopted by Messrs. J. E. Gray, St. George 
Mivart, and Huxley. 
Several zoologists have, however, regarded the structural differences between the Apes 
and Lemurs as so important that they could not be included in the same order. In 
1830, Wagler proposed that the Apes should form the order Simice, and the Lemurs the 
order Lemures. Gratiolet also separated the Lemurs from the Apes, and placed them 
at the head of the Bats and Insectivora ; Paul Gervais is also of opinion that they 
should form a distinct order. M. Alphonse Milne-Edwards, in his memoirs already 
quoted, adduces various reasons against including the Apes and Lemurs in the same 
order, and proposes the order Lemuria , which he considers to have closer affinities with 
the Carnivora than with the Apes, Bats, and Insectivores. Haeckel, Victor Carus, 
and Claus have also regarded the structural characters of the Lemurs as possessing an 
ordinal value, and adopting a term applied to these animals by Brisson, so far back as 
1756, have constructed for them the order Prosimii or Half-Apes. Haeckel and Carus 
regard the Lemurs as the oldest group of disco-placental mammals. By all these natu- 
ralists, with the exception of M. Alphonse Milne-Edwards, whether they place these 
animals in a distinct order or not, the Lemurs are regarded as having closer affinities to 
the Apes, Insectivora, and Bats than to any other mammals. 
The demonstration of a diffused, non-deciduate placenta in the Lemurs introduces a 
