SCIENCE AND INDUSTRY. 
(6) The determination of the cause of the very high percen- 
tage of deaths from even slight infestation at certain 
times, while at other times infestation of much of the 
body surface only causes slight mortality. This seems 
to involve, among other work, a search for a specific 
pathogenic organism. 
(c) The determination of the possibility of killing flies in great 
numbers by the discovery of more parasites, or other 
~ similar means. 
The solution of these questions requires an investigation by a 
skilled biologist, and, until such solutions are established, the 
problem cannot be considered solved. 
The work at Dalmally Station has been largely based on results 
obtained in investigations by the Department of Agriculture. In 
addition to the work described below, good results have so far been 
obtained by the use of traps and poisoned baits, and work has 
been started in breeding up Chaleid wasps. 
For the past eighteen months, fly troubles have been light at 
Dalmally, but just now (30th August), and for about six weeks 
back, the indications are that a sufficient fall of rain will bring 
the pest into full activity again. 
Of recent years, the one great stand-by of the pastoralists has 
been crutching. Experience at Dalmally and elsewhere has proved 
that a much better and much cheaper method of protection than 
crutching has been evolved. 
Three months after the sheep are shorn, they are subjected to 
a shower dip containing about 0.2 per cent. of arsenious oxide in 
solution. Several specifies on the market containing arsenic have 
been found suitable. This shower dip is repeated again three 
months later. 
In the results obtained so far, the proportion of sheep struck 
has been far smaller among the dipped sheep than among the 
undipped sheep. 
Just before lambing time, the most dangerous period of the whole 
year, the use of the Orion Downs jetting method has given two 
months’ certain protection, and may possibly give three months, 
thus putting the flocks over the very worst period. 
The following facts provide a striking example of the greater 
protection given by jetting than erutching :— 
A few weeks ago, thirty thousand (30,000) ewes were 
inspected which had just finished lambing 80 per centum of 
lambs. These ewes had been jetted with an arsenical dip 
prior to lambing. Not a fly-struck sheep was observed in the 
whole number. Before these ewes were jetted, crutching had 
been the custom on the station, and it was with much difficulty 
that the manager obtained consent from the owners to jet 
instead of crutch the sheep. He has now a better and cheaper 
method of dealing with lambing ewes. 
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