SCIE 
NCE AND INDUSTRY. 
detected at an early stage. When it proved to be necessary the reclean- 
ing of the wheat by means of the cleaning plants which will have to be 
. provided in connexion with the silo system in view of the stripping 
method of harvesting in vogue throughout Australia would be a com- 
paratively simple operation—simple, that is to say, in comparison with 
the task of dealing with the same condition in bagged wheat. 
Should it happen that the infestation by weevils of the wheat in a 
silo reached an advanced stage before being detected more radical 
measures might have to be adopted. By the cleaning process the 
majority of the adult weevils are got rid of; but the eggs and larvee 
enclosed within the grains are not affected, and under favourable condi- 
tions soon give rise to a fresh crop of weevils much more numerous than 
that which has been removed. Such « more radical and at the same 
time relatively simple method of dealing under the bulk-handling system 
with weevily grain seems to be indicated by the following :— 
For centuries a method of bulk storage of grain (rice, and, in more 
modern times, wheat) has been in vogue among the natives of various 
parts of India. Details would be out of place here; it will be sufficient 
for the present purpose to state that the grain was stored in pits or 
structures of dried mud and covered with closely packed earth in such 
a way that it was completely shut off from the air. In such air-tight 
receptacles no weevil is developed. A similar method, with similar 
results, is still followed in Malta. 
Professor Arthur Dendy, F.R.S., at one time assistant to Professor 
Sir Baldwin Spencer in Melbourne, and later Professor of Biology in 
Canterbury College, Christchurch, New Zealand, and now Professor of 
Zoology at King’s College, London, has been conducting a series of 
experiments (under the auspices of the Grain Pests Committee of the 
Royal Society), which have an important bearing on this air-tight 
method of storing grain. He finds that by keeping weevily wheat in 
airtight glass receptacles, even under conditions of temperature and 
moisture most favorable to the insects, the death not only of the adult 
weevils, but of their larvex in all stages, results in a few weeks. Wheat 
in the dormant condition gives off carbonic acid at a slow rate as a 
result of a process commonly termed respiration. Live weevils give 
off the same gas much more actively. In the air-tight receptacle 
completely filled with weevily wheat, the rapid evolution of carbonic 
acid, with the exhaustion or diminution of the small quantity of oxygen 
present in the air filling the interstices among the wheat grains, has : 
lethal effect on all the insects enclosed. And. the greater the degree of 
the insect invasion, the more rapidly is the result brought about, owing 
to the corresponding rapidity with which the carbonic acid is produced 
and the oxygen exhausted. ~ 
The importance of these experiments, and of the experience of the 
methods of storage above referred to, as followed in parts of India and 
in Malta, to those in charge of the wheat storage in this country, will 
be at once apparent. In the storage for a time of weevil-infested grain 
in air-tight bins or silos, we seem to have a remedy which lies quite 
in the path of the normal process of bulk-handling. But before a 
rational scheme of treatment can be formulated, there is need of exact 
experiments on a large scale to determine how long wheat in which 
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