534 
MR. OWEN ON THE MAMMARY GLANDS 
ture, and on skinning her while yet warm, it was observed that milk oozed 
through the fur on the stomach, although no teats were visible on the most mi- 
nute inspection ; but on proceeding with the operation two teats or canals were 
discovered, both of which contained milk. The carcase also of this female 
Mr. Maule has kindly forwarded.” 
In the preceding account, therefore, two important facts are distinctly stated ; 
the one, that the ova of the Ornithorhynchus attain the size of a large musket- 
ball, and, like the eggs of the ovo-viviparous reptiles, have a soft outer covering ; 
the other, that the fluid secreted by the abdominal glands is milk. The first of 
these statements would of course derive additional value if the period of the 
year were stated when the eggs so developed were observed ; and the precise 
part of the body in which they were situated, whether in the ovary, the ovi- 
duct, or the cloaca : also, whether they were observed at the same time that 
the female with her young was captured, or at what distance of time from that 
event. 
With respect to the supposed portions of egg-shell found in the nest, it is 
obviously far from being conclusive as to the oviparous character of the Orni- 
thorhynchus ; since, when it is considered that the excrement and urine are 
expelled by the same orifice, we may readily suppose the former to be coated, 
as in birds, with the salts of the urine, and to have given rise to the above 
appearances. 
The information respecting the mammary glands is much more satisfactory, 
and must be regarded as decisive of the question relative to their function. 
The mode of suckling appears, indeed, not to have been observed; but the 
ready escape of the secreted fluid after death, during the process of skinning, is 
corroborative of the opinion previously advanced as to the manner in which 
the milk is expelled. Among the other points of interest for which the scientific 
world is so highly indebted to the exertions of Lieutenant Maule, that of dis- 
covering the number of young produced by the Ornithorhynchus may in all 
probability be reckoned ; and it would appear, that, as in other Mammalia, it 
corresponds with the number of nipples, or outlets for the mammary secretion. 
