FLASHLIGHT PHOTOGRAPH OF ONE OF SEVERAL VARIETIES OF OPOSSUMS ENCOUNTERED 
IN THE CANAI, ZONE 
The particular opossum shown is the commonest species, and by reason of its abundance 
and its omnivorous appetite it proved a serious obstacle to flashlight photography. 
Probably 
75 per cent of the flashes fired were sprung by opossums, who found and fired the camera 
shortly after dusk, before better game was moving. 
were carefully screened and inspected 
and the employees supplied gratuitously 
with quinine. By isolating, in conven- 
iently located hospitals, all suspected or 
infected cases there was no possible 
chance for an epidemic to get a foothold. 
LOSING SANITARY CONTROL 
Now that most of the government 
towns about the lake have been disman- 
tled or occupied only by a few perma- 
nent employees, it should be easier to 1n- 
sure proper health conditions along the 
canal route were it not for several 
changes which if ignored may cause a 
reversion to the old conditions or worse. 
The change that has taken place since 
the lake filled up the lower Chagres Val- 
ley and extended far inland, flooding 
temporarily, and at places permanently, 
lowlands far beyond the zone, has already 
been mentioned. Taking the lake as a 
whole, and after the stagnation caused 
by decaying vegetation has ceased, it 
ought to be sufficiently pure for many do- 
mestic uses. Probably 90 per cent of the 
supply is the quickly delivered torrential 
rains, and the remainder, mostly during 
the dry season, is the contribution of 
small streams fed by the stored waters of 
the limestone formations; so its purity 
nearly equals that of distilled water. 
With a depth in the main part surpass- 
ing that of Lake Erie, the surface rough- 
ened and aerated by daily winds and the 
rotting vegetation replaced by aquatic 
growths favorable to purification, there 
is no apparent reason why such water 
should not be piped, as now contemplated, 
to the cities of Panama and Colon or the 
neighboring towns, as well as becoming 
an important source of supply for the 
numerous ships en route between distant 
ports. 
187 
