187 
On Irrigation in Tasmania. 
\ 
pressure engine of the common construction could do; 
thus showing that this engine will consume less fuel than 
the common engine, besides its other advantages of 
cheapness, &c. This engine will be worked on a larger 
scale as soon as a broader belt and larger millstones are 
obtained. 
Art. II. Observations upon the Condition of young 
Marsupial Animals . By E. S. P. Bedford, Esq. 
The objects which originally attracted more immediate 
attention, with reference to marsupial animals, were the 
early birth of the young, and the pouch provided for its 
reception. This living and portable nest varies in its 
shape, the direction of its opening, and the firmness of its 
structure, according to the habits of the class of animals it 
belongs to; the movements of the kangaroo, wombat, 
opossum, native cats, and others requiring very different 
degrees of support for their young. This variation appears 
to be provided for by the size of the walls of the pouch, 
its degree of openness, and the situation of its orifice. 
It was generally supposed that the marsupial bones— 
those peculiar pelvic appendages seen in the marsupial and 
the monotrematous animals—were placed for the purpose 
of affording support to the marsupium , or pouch : this has 
long since been known to be incorrect, its presence in the 
male animals and in the Monotremata , where there are not 
pouches, points out that they have a different office ; and 
it is now believed that they are placed for the more firm 
attachment of the abdominal muscles. This, no doubt, is a 
correct explanation of their office ; and if their relative 
size is compared with the support required for the abdomi¬ 
nal muscles in particular animals, it will be found that 
the marsupial bones are largest where the ribs give least 
