518 
MR. OWEN ON THE MAMMARY GLANDS 
the uterine organs with reference to that of the, glands in question. In this 
way a series of facts has been ascertained, which I have ventured, from the 
interest of the subject to which they relate, to submit to this learned Society. 
But as the value of these observations, in a great measure, arises out of the 
state of doubt in which the question was left by previous researches, I have 
premised a short abstract of the anatomical history of the Monotremata. 
Echidna Hystrix and Ornilhorhynchus paradoxus were first described and 
figured by Dr. Shaw ; the former, as early as the year 1792, in the third volume 
of the “ Naturalist’s Miscellany,” under the denomination of Myrmecophaga 
aculeata ; the latter, in the tenth volume of the same work, in 1799, by the 
name of Platypus anatinus. In the following year this extraordinary animal 
received a further description, together with its present generally adopted ap- 
pellation, from Professor Blumenbach ; and about the same time, Sir Everard 
(then Mr.) Home gave an account of some of its anatomical peculiarities, which 
appeared in the Philosophical Transactions for the year 1800. As these ob- 
servations however were limited to the head and beak of the Ornithorhynchus, 
they threw but little additional light on the situation of that animal in the 
natural series. In the meanwhile. Professor Blumenbach placed the Orni- 
thorhynchus among the Palmata of his system of natural history, intermediate 
to the otter and the walruss ; while Dr. Shaw more correctly referred it to the 
Bruta of Linnaeus ; and, although limited to such traces of affinity as the 
outward form alone presented, he announced the alliance of this species, as 
well as of the Echidna, to the Myrmecophagse. 
The important memoirs on the anatomical structure of both these animals 
by Sir Everard Home, which were read before the Royal Society, and pub- 
lished in the Philosophical Transactions for 1802, drew the attention of the 
scientific world more strongly towards their remarkable peculiarities and devi- 
ations from the normal type of the Mammalia. In these investigations, the 
author, having brought to light numerous instances of mutual affinities before 
concealed beneath very dissimilar exteriors, grouped the two animals together 
under the same generic appellation. He also announced his opinion that they 
differed considerably in their mode of generation from the true Mammalia, 
grounding his belief on the peculiarities of the organs themselves, and on the 
absence of nipples in both species, and especially in the female of the Orni- 
thorhynchus paradoxus. 
