"We have thus shown that the typhoid or house fly is a general and common carrier of pathogenic bacteria. It may carry typhoid fever, Asiatic cholera, dysentery, cholera morbus, and other intestinal diseases; it may carry the bacilli of tuberculosis and certain eye diseases. It is the duty of every individual to guard so far as possible against the occurrence of flies upon his premises. It is the duty of every community, through its board of health, to spend money in the warfare against this enemy of mankind. This duty is as pronounced as though the community were attacked by bands of ravenous wolves." Again: "A leading editorial in an afternoon paper of the city of Washington, of October 20, 1908, bears the heading, 'Typhoid a National Scourge,' arguing that it is to-day as great a scourge as tuberculosis. The editorial writer might equally well have used the heading 'Typhoid a National Reproach,' or perhaps even 'Typhoid a National Crime,' since it is an absolutely preventable disease. And as for the typhoid fly, that a creature born in indescribable filth and absolutely swarming with disease germs should practically be invited to multiply unchecked, even in great centers of population, is surely nothing less than criminal." The whole bulletin (No. 78, Bureau of Entomology) should be read and studied by all who are interested in this subject. OTHER FLIES Occasionally other flies looking more or less like the house-fly are seen in houses. Some of these have the same type of sucking mouth-parts and have habits very similar to the house-fly, but as they are usually much less common and as nearly all that has been said in regard to the house-fly would apply equally well to them and as the same measures should be adopted in fighting them they need not be discussed further here. I have already called attention to the fact that a fly which looks very much like the house-fly is sometimes found in the house and will often bite severely. It has quite a different style of beak, one that is fitted for piercing so it may suck the blood of its victim (Fig. 51). As these flies often seem to be more persistent before a rain the weather prophet will tell you that "It is surely going to rain for the house-flies are beginning to bite." These stable-flies, as they are called, are great pests of cattle and horses in some sections. It is thought that they are important factors in the spread of some of the diseases of domestic animals, and their habit of sometimes attacking human beings makes it possible for them to carry certain disease germs from animals to man or from man to man. CHAPTER VI MOSQUITOES