SCIENCE AND INDUSTRY. 
Pending the discovery of some enemy or enemies which shall destroy or 
control the pear, every effort should be made to prevent the further spread of 
the pest. This should be attempted by the combined use of settlement and 
poison. ry 
Belts of pear country, surrounding each large area of infestation, should be 
carefully selected. Hach of these belts should comprise land in such a condition 
of infestation that it can be economically cleared by the use of poison. Settlers 
should be established on these cleared belts, which will completely enclose the 
very heavily infested areas. These settlers should be granted a tenure of the 
most favorable nature with the condition, which should be strictly enforeed, that 
they must not permit the pear to spread on to their selections. Portions of 
the belts at present occupied by pastoralists should be brought under the same 
condition. 
2. The second class of pear country consists of infested areas of very large 
extent, containing more or less scattered clumps of pear. ‘These areas are 
scattered about the country in patches, and they surround the heavily infested 
areas on all sides, joining up the centres of infestation already referred to, and 
tending by the increasing density of the pear which they carry to spread the 
first class over the whole of the infested area. 
This class of country, which will be outside the protective belts suggested in 
the foregoing, can be cleared at a moderate cost by the use of suitable poison 
applied at the proper season, the dead or seriously injured pear being subse- 
quently destroyed by burning. 
It is probable that cost of doing this will in some cases be higher than the 
value of the cleared land, but notwithstanding this it should be undertaken as 
a national problem. 
3. The third class consists of very lightly infested areas situated on the 
extreme edge of the other two classes of infestation, and also scattered areas in 
process of development, where seeds have been carried by birds and cattle. 
There is no difficulty at all in clearing such country and in keeping it 
cleared at a comparatively trivial cost by the use of suitable poison. The task 
of doing so does, however, call for constant attention on the part of the settler, 
and the duty of devoting this attention is one that should be emphatically and 
repeatedly brought to his. notice. : 
It is to be noted in connexion with this problem that roads, reserves of land, 
and Crown property are in some districts left uncleared where the pear has 
otherwise been cleared. This infested land remains a source of re-infestation for 
the whole district. It is essential in connexion with any plan for clearing any 
district that such roads, reserves, &c., should be cleared and kept clear at the 
same time as all other infested land in the district. Unless this is done, a quite 
unnecessary expense is entailed on the surrounding land-holders, and the cost 
of keeping cléar remains a permanently occurring expense instead of being a 
quickly diminishing quantity. 
The problem of attempting to cope with the prickly pear in Australia is one 
which will severely tax the administrative and material resources of the com- 
munity, and this fact should be clearly stated and borne in mind by the Govern- 
ments concerned. 
