Transmission of disease may also occur by the infection of open wounds through contact with infected flies. This is true of all pus formation in wounds. The simple contact of a fly infected with the disease may cause Oriental plague, sore eyes, and possibly granular eyelids. A fly infected with dysentery or typhoid fever may cause either of these diseases by simply coming in contact with the lips of susceptible persons. The fly in the house should be relentlessly pursued and destroyed. The house which is carefully screened and protected from flies is infinitely safer than one not so protected. In the spring of the year the house fly begins to take on life. Eggs which were laid the preceding fall begin to hatch. At first the fly is only a little worm wriggling in some pile of filth. The eggs are usually laid and the grub developed in a manure pile or some mass of garbage or other filth. Before the grub develops into the fly it is easily destroyed. If everything in and about the house were kept scrupulously clean, and if every manure pile were kept carefully screened or covered so as to protect it from flies, there would be no difficulty in preventing the fly nuisance. The most effective way to accomplish this is to destroy the breeding places. The importance of this may be seen when it is considered that one fly produces one hundred and twenty-five millions or more of its kind in one season. Stables.--Manure is by far the commonest material in which the fly lays her eggs. All stables should be kept scrupulously clean. No manure should be allowed to accumulate where it will be exposed to flies for even a few minutes. Immediately after it is dropped by an animal, it should be removed and covered. Manure may be treated with considerable quantities of lime without interfering with its fertilizing value, and in this way the development of the eggs laid in it by the flies can be practically prevented. The floors of stables should be thoroughly flushed with water at least once in every twenty-four hours. Privy Vaults.--Human excrement also affords an excellent breeding place for flies. In army camps the latrines are the points from which much infection is transmitted to troops, and thousands of the men have lost their lives by contracting typhoid fever transmitted in this manner. During the summer time all open vaults and dry closets should be treated continuously with lime, crude creolin or crude carbolic acid, and they should be carefully cleaned out at frequent intervals.