120 THE AUSTRALIAN NATURALIST. 
strongest feelings of wonder and reverence which go on in- 
creasing with increasing acquaintance. The secrets of the ar- 
chitecture of the canyon-like valleys which dissect the mountain 
plateau have unfolded themselves slowly; but each succeeding 
‘visit has afforded new delights resulting from an increasing 
facility in interpreting causes from observation of the effects 
produced. During a period so full of stress as the last five 
years, a contemplation of the grandeur of Nature, as exhibited . 
in gorge and precipice, has given ground for hope that long 
periods of peaceful prosperity may follow this Empire-shaking 
war, just as the Grand Canyon River has long spells of quies- 
cence between the periods of its turbulent activity.- 
AN ENEMY OF THE RED BACKED SPIDER 
(Lathrodectus liasseltic, Thor.) 
By W. W. Frocearr, F.L.S., F.E.S. 
During the last month two of the reputed poisonous Red- 
backed Spiders (Lathrodectus liasseltic), finding a secure home 
in the corners of the Fly Aviary at the Government Sheep Fly 
‘Experimental Station at Moree, with abundance of flies right 
to their hands, spun their parlours in the background, and con- 
structed the open roomy nurseries on the side, in which they 
constructed and suspended their round light-brown silken co- 
coons, four in number, each packed with soft semi-transparent 
eggs, up to two hundred in number. ‘The officer in charge, Mr. 
Macdonald, always on the lookout for the spread of the sheep 
fly chalcid wasp, looking round one morning noticed a number 
of tiny black chalcid wasps wandering quite unconcernedly about 
in the spider’s nursery, and on closer examination found that 
these little shining black wasps were emerging from one of the 
cocoons, being evidently parasitic upon the eggs, enclosed be- 
neath its shelter. 
Further search proved that in the station skin shed, where 
the same spiders had ‘many cosy corners, large numbers of the 
cocoons were full of tiny wasp parasites, in all stages of de- 
velopment, instead of baby spiders. 
Naturally he considered from casual examination that Masonia 
. brevicornis, the sheep fly chalcid wasp, had another foster 
mother in the Red-backed Spider, but when the writer placed 
them under a strong lens it was at once seen that they were 
