﻿516 BANKS. 



FACILITIES. 



The breeding grounds of Anophelince were so near to the laboratory 

 where my indoor investigations were carried on, that it was an easy matter 

 to go from the outdoor cages to the workroom several times a day if 

 necessary. At first, certain places were simply watched daily and the 

 development of the larva? and pupae noted, but as work went on it was 

 found desirable to isolate individuals and eggs in order to determine with 

 exactness the various periods of growth. I took with me from Manila 

 most of the portable apparatus necessary, but many features which needed 

 to be constructed on the spot were furnished by the naval authorities, 

 all of whom, without exception, did everything in their power to aid my 

 work. I wish in this place to express my thanks for their assistance. 



SUBSIDIARY INVESTIGATIONS. 



On the 2 2d of April a battalion of marines, fully equipped for heavy 

 marching, left Olongapo under the command of Maj. E. Iv. Cole, United 

 States Marine Corps, for a military reconnaissance of the region around 

 Mount Pinatubo to the north of Olongapo and distant some 48 kilometers. 

 This expedition from the time of starting until the return to Olongapo 

 occupied five and a half days, during which time the whole command slept 

 at no one place for two consecutive nights. We left the seacoast at the 

 town of Subig 12J kilometers north of Olongapo at the head of Suing 

 Bay and struck inland, there being a continuous and gradual rise in 

 the land until the second day, when the country became strictly moun- 

 tainous. The night camps were always pitched in the vicinity of running 

 water, but in no ease was stagnant or semistagnant water encountered 

 during the trip. A few mosquito larva? were found at Santa Fe in the 

 river near the camp, but the specimens collected died lief ore reaching 

 maturity. However, they were not Anophelines. 



On the last night of the expedition (April 26) at a small place south 

 of Castillejos, Zambales, the sleepers were annoyed by considerable num- 

 bers of Devoidya joloensis Ludlow (D. fusca Theobald, var. joloensis 

 Ludlow). 1 This species probably breeds in the rather sluggish river 

 near this place, although a search did not reveal the larva? at that time. 



These mosquitoes were the only ones encountered on the trip and it 

 is noteworthy that no single individual of the entire expedition, com- 

 prising some one hundred and twenty-five men, was attacked by malaria 

 subsequent to his return to Olongapo, within the usual incubation period 

 of the disease ; in fact, a careful observation of the men of the command 

 for two months after their return showed that, where there was any 

 malaria, it was a recrudescence of the aestivo-autummal type and in indi- 

 viduals who had been suffering from the disease for some time before this 

 trip. 



1 Theobald says in Mono. Culic. ( 1907), 4, 165, that this variety merits specific 

 rank and I have so indicated it. 



