EDITORIAL AND GENERAL. 



16; 



vines that overgrow the trees, some limit 

 their breeding to notches of bamboo 

 stalks, and a number of varieties are sat- 

 isfied only with crab holes in the ground. 

 One of the species carries yellow fever, 

 some spread malaria, and others are in- 

 strumental in carrying other diseases. 

 On the other hand, a large number of 

 species are entirely harmless, and several 

 have no inclination to bite human beings. 



Thus, aside from the pure contribu- 

 tions to knowledge resulting from the 

 trip, this exploration has rendered possi- 

 ble more economic and efficient methods 

 for exterminating the disease carriers. 



Mr. Busck spent three months on the 

 Isthmus during the breeding time, cov- 

 ering the end of the dry season and the 

 early part of the rainy season, and se- 

 cured larva? of eighty-three species, of 

 which thirty were new to science. 

 With seven additional species already 

 known, this constitutes the largest 

 number recorded from any one locality 

 on earth. Most of the material gathered 

 has been deposited in the U. S. National 

 Museum. 



Mosquitoes do not fly far from the 

 place where they are hatched. They 

 keep close to their food supply. Those 

 that affect the inhabitants of a town or 

 camp, normally do not come from a dis- 

 tance greater than two hundred yards. 

 It is this fact that renders the sanitary 

 work of the Canal Commission possible. 



SANITARY METHODS. 



The land about every settlement is 

 cleared by the removal of all brush, un- 

 dergrowth, and grass ; only shade trees 

 and fruit trees are left, and these are 

 thinned out to admit sunlight and free 

 ventilation. When practicable, swamps 

 and lowlands are filled in with some of 

 the immense supply of material taken 

 from the great Culebra cut. Then the 

 whole area is drained so that the sur- 

 face water will run off. Ditches and 

 slow-flowing streams are kept clear of 

 mosquitoes by drippings of oil or of cop- 

 per sulphate. Swamps and pools are oiled 

 at least once a week. Water barrels, 

 buckets, and pails must be screened or 

 oiled, and all tin cans must be buried. 

 Even the old cast-off machines, brush- 

 covered relics of French occupation, are 

 drained of their puddles of water. If 

 many insects infest a camp or town it is 

 fumigated. By carrying out these meth- 

 ods of general extermination exception- 



ally thorough results have already been 

 obtained. 



Still greater efficiency may be secured, 

 Mr. Busck believes, by turning to use 

 additional scientific knowledge of the 

 habits of special varieties of mosquitoes 

 found on the Isthmus. The opportu- 

 nities opened about the Canal for fur- 

 ther enhancing man's knowledge of dis- 

 ease-preventing methods are peculiarly 

 favorable, and a grasping of them makes 

 for sanitary welfare not only in Panama, 

 but in all the tropical countries of the 

 earth. 

 YELLOW FEVER \ND MALARIA MOSQUITOES 



One important feat has already been 

 accomplished. Ihe yellow-fever mos- 

 quito, the only kind in America spread- 

 ing this infection, scientifically called 

 Stegomvia, is very scarce. It is possible 

 to live for weeks on the Canal without 

 seeing a single specimen. This mosquito 

 is a strictly domestic animal, never found 

 away from man. It breeds only in ar- 

 tificial receptacles, such as barrels, wat- 

 er-coolers, bottles, tin-cans, in and 

 around human habitations. The author- 

 ities, knowing this, have it well within 

 their power to eliminate absolutely this 

 dangerous insect, and to render a yellow 

 fever epidemic impossible on account of 

 the total absence of the only agent that 

 spreads it. 



The malaria carrying varieties, in- 

 cluded under the general name of Ano- 

 pheles, are also subject to strenuous at- 

 tack. Usually the species of this group 

 deposit larva? along the edges of slow- 

 flowing streams and stagnant pools, but 

 specimens were also secured from the 

 bottom of an old boat, from an aban- 

 doned dump car, from holes in trees, 

 and in similar out-of-the-way spots. It 

 has not yet been determined whether all 

 of these are instrumental in carrying ma- 

 laria, and therefore they may furnish a 

 fertile field for investigation. 



Certain genera, technically called Me- 

 garhinus, Psorophora, and Iutzia, were 

 found, which, instead of spreading any 

 disease hostile to man, wage war on 

 their weaker cousins and at times even 

 on their brothers and sisters. Rather 

 than exterminate mosquitoes of these 

 habits, it might be well to cultivate them 

 and to enlist them as allies of the san- 

 itary authorities, were it not for the fact 

 that some of them are exceptionally an- 

 noying biters of mankind. 



