86 SOME CAUSES OF THE DECAY OF AUSTRALIAN FORESTS. 
7. Caterpillars destroying the bark.—There are some caterpillars 
which grow several inches in length whose destructive powers are 
considerable. whole colony of them, making parallel roads as 
they eat their way round the barrel of a tree, devouring both bark 
and sap-wood, are quite sufficient to killthe tree. But the number 
of trees actually killed in this way, so far as the writer’s observa- 
tions extended in the Meredith district, was very small. On the 
other hand, there were thousands of young trees dying, and when 
the bark peeled off them, leaving the white stems, there was often 
not a caterpillar track to be seen. 
The foregoing are some of the explanations which were put forth 
tion. But while the white man was making his guesses in the 
matter some one had put the question to the black man, and 
received an answer which may take its turn for investigation. 
8. Ravages of opossums.—The ase of the abor iginal _ con- 
tedonthe matter was “too many big one ’possum.” The meaning 
of this oracle was, in effect, that owing to the multiplication “of the 
opossums, their ravages amongst the leaves of the trees were 
extensive enough to account for the destruction of the trees. So 
proportions between ranches counted and all the remainder 
of the tree, a rough estimate was formed of the number of leaves 
on the who The smaller trees gave a result of about 
70,000 leaves, while the adi gave 130,000. The mean between 
,000. Then, as to the amount of destruction which 
an opossum could do in one night, it was in the first instance 
assumed as a guess that fifty leaves would not be too high an 
estimate for each opossum. According to this calculation 
: opossums would destroy one tree per night, or 365 in 
‘the year. Allowing eighteen trees to an acre, the Posse 
figures would involve the destruction of every leaf on 
the trees on a space of 20 acres. As to the numbers of the 
opossums in the district under consideration as well as generally 
there were sundry sources of information. During 1865 an 
active man was engaged in a profitable i see shooting 
