The Birmingham age-herald., 1907-04-28
SteasmYia Studies

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 Dr. Edward Francis of the Marine hospital service, stationed for two years in Mobile, completed there i'm portant observations on the life cycle of the yellow fever mosquito. These observations have been published by the Marine hospital service in Wash ington.
 The striking feature of Dr. Francis observations is that eggs which have been kept dry for over six months matched out mosquitoes under favora. ble conditions. This may account for the fact that soon after heavy rain mosquitoes are more plentiful than usual. It is deemed likely that the eggs being laid in the little pools of water near the roots of grass cling to the grass when the water dries out, and when heavy rain comes and they are again submerged long enough to develop, the natural process which had been Suspended by the intervening dry spell is resumed.
 He found larvae in every month of the year in rain barrels in Mobile, and he had no difficulty in developing them at room temperature into adult mosquitoes The favorite breeding places were brown jugs left standing in yards or in other artificial water containers. As a rule he found no larvae in the cold months in natural earth bottoms He submits story of one brown jug full of interest to all mosquito-infected districts, as follows:
 Eggs were laid on the surface of the water in jar on August 16, 1906. The jar was then tilted so that the eggs were left on the sides of the jar, above the level of the water. The jar was then set aside in a wardrobe, in a room which had no fire in it all winter and the doors and windows were open day and night
 On October 15 scraped off some of the eggs put them in water, and in sixteen hours they had matched; the larvae deyel- oped into adult mosquitoes.
 On February P, 1907 1 added enough water to the jar to cover the eggs and raised it to a temperature of so degrees; seventeen hours later two dozen larvae had hatched> later in the day another dozen had matched.
 March 6-Nine pupae.
 March 7-Sixteen pupae.
 March S--Ten adults.
 March 11-Sixteen males dead on sur face of water; five females fed on blood; sixteen females alive; four males alive.
 March 12-Ten fed blood
 March 13-Three fed blood
 March 14-Fifty eggs laid.
 March 15-Fifty eggs laid
 March 16-Seven females and two males alive.
 March Tone fed blood.
 March 1S-Four fed blood.
 March 19-Two fed blood.
 March 20-Sx females and two males alive; about 100 larvae in jar; 100 eggs re- moved from surface of water and dried on paper.
 March 23-One fed blood; 115 eggs re- moved and dried on paper.
 This experiment shows that the eggs which are kept dry at practically outdoor temperature from August 16 to February 27. were still viable. and when covered with water at kept at so degrees, de veloped by March into adults which on March IA laid eggs which matched into about 100 larvae on March 20 thus com pleting the life cycle.
 Dr. Francis has recently been placed in charge of the Mobile quarantine station, and he is now drying eggs which he will test for viability one year hence.
 The moral of Dr. Francis story Is, kill all mosquitoes. Kill them before they have opportunities to deposit eggs, for those eggs will hatch out early or late The only comprehensive remedy consists in campaign of ex- termination.