FLYING IN MAMMALS 
save the bare fact that it is, like them, a marsupial. 
The real and genuine opossums belong to the carnivorous 
section of the marsupials, the Polyprotodonts. They 
are, however, tree climbers and have the same pre- 
hensile tail and sharp claws which distinguish our 
Tvichosurus. The pouch of Trichosurus only harbours 
at most two young ones and more usually one only. 
It has not the often enormous philoprogenitiveness 
of the “’ possum.” In Australia and Tasmania it is 
hotly pursued on account of its moderately valuable 
fur. This is its attraction to the white man. The 
black man thinks less of the fur than of the flesh be- 
neath it, and regards Trichosurus, in spite of its rank- 
ness in the European nostril, as desirable meat. 
BELIDEUS BREVICEPS 
We must not leave the diprotodont marsupials 
without a reference to the flying forms of which the 
present representative (also called Petaurus breviceps) is 
often to be found at the Zoo. It is asmall, soft-furred, 
mousy-looking creature of grey colour with a black 
stripe down the back. It is not more than eight inches 
long and has a bushy tail of about the same length. 
The term “ flying ’’ as applied to these phalangers must 
not of course be taken literally. They cannot soar 
upward like a bird ; the most that can be done is a series 
of skims from bough to bough, the distance to the ground 
being lessened at each effort. The flying, such as it 
is, is effected by a parachute-like membrane attached 
along the sides of the body between the limbs. It 
seems to be likely that all kinds of flying really originated 
from some such mechanism, which gradually became 
restricted to the fore-limbs in the more perfectly flying 
birds and bats. A loose fold of skin at the sides is 
sufficient for a beginning; this becomes intensified, 
and then the “patagium’”’ in birds is limited to the 
AS. 145 ie 
