226 MR. R. OWEN ON THE YOUNG OF 
water; and having at the same time prepared a little Cow’s milk by first coagulating it 
with spirit, and then diluting the coagulum, I compared the two substances under a 
high magnifying power. The ultimate globules of the Ornithorhynchus’s milk were 
most distinctly perceptible, detaching themselves from the small coherent masses to 
form new groups: the corresponding globules of the Cow’s milk were of larger size. 
Minute transparent globules of oil were intermixed with the milk globules of the 
Ornithorhynchus. A drop of water being added to a little mucus, it instantly became 
opake ; and was resolvable by minute division into transparent angular flakes, entirely 
different from the regularly formed granules of the milk of the Ornithorhynchus. 
In the smaller specimen the stomach was empty; when distended with air it ex- 
hibited a less disproportionate development. It was situated in the left hypochondriac 
and lumbar regions. The intestines contained air, with granular masses of a mucous 
chyme adhering to their internal surface. This condition of the digestive canal would 
seem to show that no long period had elapsed since the birth of the specimen, and that 
lactation had either not been in full action, or that the young one had been deserted by 
the parent for some time before it was taken. 
In both specimens the spleen bore a proportionate size with the stomach ; and as 
the difference in the development of the stomach was considerable, the correspondence 
of the condition of the spleen with that of the digestive cavity was made very obvious. 
The difference in the development of the liver was not greater than corresponded with 
the different size and age of the two specimens. But the pancreas in both bore the same 
ratio to the stomach as the spleen. This would seem, therefore, to afford some indica- 
tion of the organs with which the function of the spleen is more immediately related. 
The intestinal canal in the larger specimen was situated almost entirely on the right 
side of the abdomen. The cecum, in both, was very minute and filamentary. I exa- 
mimed the ilewm, and more especially in the usual situation above the cecum, but could 
not perceive any trace of the pedicle of the umbilical or vitelline vesicle. The other 
vestiges of foetal organization were more obvious than in the ordinary Marsupial or 
ovoviviparous Mammalia. 
In both specimens, but more distinctly in the smaller one, the umbilical vein was 
seen extending from a linear cicatrix of the peritoneum, opposite the middle of the abdo- 
men, along the anterior margin of the suspensory ligament, to the liver. It was reduced 
to a mere filamentary tube, filled with coagulum. From the same cicatrix the remains 
of the umbilical arteries extended downwards, and near the urinary bladder were con- 
tained within a duplicature of peritoneum, having between them a small flattened oval 
vesicle, the remains of an allantois, which was attached by a contracted pedicle to the 
fundus of the bladder. 
As both the embryo of the Bird and that of the ovoviviparous Reptile have an allantois 
and umbilical vessels developed, no certain inference can be drawn from the above 
appearances as to the oviparous or viviparous nature of the generation of the Ornitho- 
