228 MOSQUITOES OF NORTH AMERICA 
to note, also, that at this time two of the largest pools which were situated 
close by, and have been described as swarming with mosquito larve, had been 
filled in with sand. Samples of water taken from various parts of the town were 
examined for the amount of chlorine present in them, the result is given in the 
following table. 
Chlorine expressed 
Chlorine per 
“Sample of water. as percentage 
100,000 parts. of NaCl. 
1. Public well, New Town, no mosquitoes present 
INC WALSE. oie 56 6 ease ene ORES TASS te ieee 161.2 265 
2. Public well, Lancaster Street, water rather foul, 
Anopheles larve present in numbers .... ... 1148.0 1.89 
8. Public well in Clifton Road, behind Hospital, no 
larvae present...... 6. ce cece ete eee e eens 186.0 0.3 
4. Water (tidal) found in drain near sluice gate, 
Blucher Street, A. costalis and large quantities 
of @. halassios present, .......6 6 eee teen ees 1088.5 1.71 
5. Small well in private garden, Culex present, few 
CNG chen Kaleo ced we UOEE OVO d eet eeaee 27.9 0.04 
6. Small well in native compound, Victoria Street, 
Culex larvee present ........ ce cece cece eee 1145.0 1.88” 
To refer briefly to the other records of Anopheles breeding in sea-water, this 
habit was probably first mentioned by Grassi, who observed it at Metaponto, 
Italy. Nuttall, Cobbet and Strangeways-Pigg captured larve six times in 
brackish water. A. Clerc has experimented with larve of Anopheles maculi- 
pennis; he found that larve placed in water with 44-46 grammes of salt to the 
liter would die if very young, but the older larva developed and produced imagos. 
Christophers and Stephens found Anopheles larve to occur at Accra in brackish 
pools 0.6 per cent salt. Foley and Yvernault found that in Algeria Anopheles 
‘chaudoyet breeds in saline water containing 40 grammes of salt to the liter. 
Chatterjee found larve of what he called Anopheles rossi, but which it would 
now seem were A. Judlowi#i, in brackish water in India. Gholap found another 
Indian species, Anopheles stephensi, breeding in salt water. 
In America several species of Anopheles have been found to breed in brackish 
water, but none of them exclusively so. Chapin, in Rhode Island, found Anoph- 
eles larve living in brackish water on the coast. Anopheles crucians has been 
found to breed in brackish water in New Jersey and Louisiana, and we have 
already mentioned that Smith has found larve of A. quadrimaculatus in New 
Jersey under similar circumstances. It is worthy of note in this connection that 
Anopheles crucians seems to thrive best in the vicinity of tide water and to occur 
much less abundantly inland. 
Anopheles albimanus, of tropical America, according to information furnished 
by Mr. A. H. Jennings of the Isthmian Canal Commission, breeds in strongly 
brackish water as well as in fresh water. The same may be said of Anopheles 
tarsimaculata, a geographic form of A. albimanus, and of A. argyritarsis. This 
last statement is made on the authority of Peryassi. The Brazilian observers 
made a series of laboratory experiments to determine the degree of salinity in 
which these larve could develop to imagos. They found that in slightly brackish 
