14 NATURAL SCIENCE [July 
WESTRALIAN WATER-SUPPLY 
ONE of the difficulties in the Coolgardie and Kalgoorlie Goldfields is 
the absence of water. ‘The success that has attended the sinking of 
Artesian wells in the sister colonies, notably in Queensland, to 
which we have often referred, suggested that similar action might 
be taken with profit in Western Australia. Mr A. Gibb Maitland, 
however, the Government Geologist, in a report that he has just 
sent us, comes to most pessimistic conclusions. The Coolgardie 
country consists for the most part of granitic rocks, which are 
weathered on the surface so as to form a superficial water-bearing 
layer of no great depth, but yielding enough water for ordinary 
purposes in certain spots; this water, however, is usually brackish. 
Below this weathered zone, however, none of the rocks are sutftici- 
ently porous to allow of the absorption and transmission of water ; 
and since they are likely to be still more compact at greater depths 
there is small hope of obtaining a supply from that source. Very 
much the same conditions obtain at Kalgoorlie, and Mr Maitland 
does not recommend the continuance of any deep borings. There 
is great demand for water at Cue to work the crushing plants, but 
the nearest locality from which water can be obtained is Millie 
Soak, about ten miles to the north-east. Here is a bed of magnesian 
limestone, in which there have already been sunk wells that yield a 
supply of 1000 gallons per diem. ‘The catchment area, however, 
does not appear to be large, and the quantity of water depends 
largely upon seasonal rains, so that the bed could not withstand a 
constant daily drain upon it of a quarter of a million gallons, which 
is the amount required. From My Maitland’s refusal to recommend 
further deep borings we assume that the conditions which govern 
deep-water-supply in Western Australia are not the same as those 
that obtain in Sweden, where, as Baron Nordenskiold has shown, 
fresh water can always be obtained at a depth of 30-40 metres 
below sea-level. 
CoRN-MIDGES AND THEIR ENEMIES 
Or high scientific and practical interest is Dr P. Marchal’s recent 
paper, “ Les Cécidomyies des Céréales et leurs Parasites ” (Ann. Soc. 
Ent. France, 1897, pp. 1-105, pls. 1-8). The famous Hessian 
Fly (Cecidomyia destructor) is naturally treated at greatest length, 
the three forms of its larva and the formation of the puparium being 
described and figured with many details. The parasites which are 
of the greatest service in keeping the midges in check, are mostly 
iminute hymenopterous grubs (Chaleids and Proctrotrupids). Among 
the latter, Zrichacis remulus, Walker (parasitic on Cecidomyia 
Avenae, Marchal) is described in detail. Its first larva is cyclops- 
like. Three or four of these live on the nervous system of a 
cecidomyid larva, and the nerves of the host degenerate with the 
