PRESIDENTIAL ADDRESS. 14 
The rats had come from the north, from the great dried-up 
river beds of the Finke, the Alberga and the Macumba, and 
smaller rivers which, in times of extraordinary rain, pour 
their floods into the north-west area of Lake Eyre. At any 
rate, the blacks and old bushmen told me that the rats 
came from these usually dry river beds, which, of course, 
contain many (so-called) permanent water holes. I heard 
also that this was not the only rat migration known in 
these parts.’’ Mr. Bagot attributed the fact that the rats 
travelled southward and not northward to their keeping 
‘to the area where are the artesian springs, and where also 
temporary surface waters are more frequent than in the 
drier districts divided from the Lake country by faults.’’ 
He adds: ‘‘But the line of artesian waters breaks away 
from Maree (Hergott Springs) towards Lake Blanche, 
where it finally ends, and the cretaceous and oolitic forma- 
tions butt up against the older strata.extending eastward. 
This stretch is sandy and stony, there are but few springs 
in it, and the rats did not make in that direction. They 
turned southwards at Maree, following approximately the 
course of the railway through better country intersected at 
first by creeks coming from a range to the westwards, and 
after passing Mt. Deception they followed the plain be- 
tween the Flinders Range and Lake Torrens, passing through 
that range where the railway passes, and finishing up their 
journey at Quorn, some 240 miles from Adelaide, where 
they appear to have succumbed to nature or the hardships 
of their march. They appear to have spread 30 to 40 
miles wide, always keeping the line of country where food 
and water was least problematical. I might here mention 
that no rats came from the Cooper River to Maree, the reason 
being, I surmise, that they would have had to cross 90 miles 
of stony desert, where no surface water is (or was), and 
where bores struck the secondary formation at 1200 feet 
without penetrating a water-bearing bed. During the in- 
