ORDER OF MARSUPIATA. 
The Marsupials, called also Didelph.es in Blainville’s classification, 
are characterised by the existence, on the anterior portion of the 
pelvis, of two long, narrow, articulated, and movable bones, which 
serve in the females, at least in the majority of the species, to 
support a pouch, situated below the abdomen, and called the 
marsupial purse or bag ( marsupium , a purse) . These bones, which 
have taken the name of marsupial bones, are not peculiar to the 
females ; they occur also in the males. The animals which are 
provided with them constitute, therefore, a very great anomaly 
among the Mammalia, especially as this modification of the 
skeleton is connected with a very peculiar mode of generation. 
In the Marsupials, in fact, the young, when they leave the 
uterus, are not perfectly formed, as is the case with the rest of the 
Mammalia ; they are prematurely expelled thence, and attain their 
full development in the abdominal pouch. Thence two phases in 
the gestation : the uterine gestation and the marsupial gestation ; 
the first relatively short, the second much longer. We thus find 
that these animals have, as we may say, two births : the one coin- 
ciding with the arrival of the young one in the purse or bag ; the 
other with its departure from this natural cradle, and its contact 
with the outer world. The duration of the gestation, considered 
in its two elements, varies according to its species. In the larger 
Kangaroos the foetus is introduced into the pouch on or about the 
thirty- eighth day after fecundation, and it remains there for eight 
months. 
It is not, as one might suppose, by an internal force — by a 
more or less energetic muscular action — that the transfer of the 
young from the uterus to the marsupial purse is effected. 
From the experiments of a learned English anatomist, Professor 
Owen, it appears that the mother herself draws them down, by 
