1915] . Behavior of Anopheles 235 
G. Composition of Water. By order of the Chief Sanitary 
Inspector, daily samples of water from the salt-marsh were 
sent to the Ancon Hospital laboratory for determination of 
salt content. After eliminating such samples as appeared 
untrustworthy, the following table was prepared. All samples 
were from water where larve were numerous. 
J. CHLORINE CONTENT OF SALT-MARSH WATER. 
Sea-water—22'000 parts of Cl per million. 2.5.06 24) sere eS. ee Se nO RO227G 
Pocw linen water—i19: 000 parts per millon. vache. si 6 0) concen 0.019% 
MAXIMUM. 
Pantse Ol Clie — Oo tobe secant —« YpnOu lone 
per Million | water water 
PNT IE Seat ae reat ae eer es 23,500 107.0 123.7 
PATTI lg 2s Pe AE OU A eee Na a Ns 21,000 95.0 110.0 
IVT Tee eee <M lowercase ae ie tess Ad ea 19,083 86.0 100.0 
May AS Hee cee ne ping n ar eke kw get ne 18,833 85.0 99.0 
LE Dagestan ea esa oe hs 18,500 | 84.9 97.4 
DANTE A oe e RS WNtees OA Wir, Sk 20,183 90.0 105.0 
MINIMUM. 
Heb sali tetrn «rare nara pgst tree haa 11,250 51.1 60.0 
TENS 1 oy3 IPA itera) a Po nner meek Ne eet RON 12,150 60.0 64.0 
CD ER OMIA Sees eae tie rer a eh sees 12,5C0 60.0 66.0 
LAF) aha aa cs abe chen EOE eo I 13,500 61.0 71.0 
ED MOM aA re ae eae ices kk, ohoe 14,000 63.6 73.0 
/ NSS Seen eae ee a 12,680 57.6 65.0 
GENERAL AVERAGE: 
Samples| Days Total Cl |Avr.per Million} % sea-water | % Limon water 
bo 
>) 
38 27 | 617,480 15,817 72. 83.0 
It is seen that larve were breeding in water containing from 
55% to 107% of ocean salinity, i. e., even in water more saline 
than’ the ocean: The density of sea-water is about 2.5% 
greater than that of fresh water, and this added buoyancy 
probably is to the advantage of such larve as can thrive in salt 
waters. Had the salt content been greater, the buoyancy 
would be too great for the larve, besides, the fact that the 
irritation due to the chemical content would inhibit any exten- 
sive breeding. 
