At the present time it is imperative on the part of the owner of an ill pig to report the fact to the nearest policeman. The owner then merely carries out the instructions supplied to him by the police so that it is almost unnecessary to state that the symptoms of swine fever are several. At times the attack is of so virulent a nature that a pig may take its food all right in the afternoon and be dead the next morning, no discoloration of the skin or other external symptoms being visible before or immediately after death. As a rule when the pig is attacked the first symptom is loss of appetite, generally accompanied by a feverish condition of the skin which shows more or fewer red spots behind the shoulder, and inside the thighs, or in those portions of the body where the skin is the thinnest and most free from hair. The great desire of the affected pig is to burrow into the litter and to remain undisturbed, save when the feverish thirst impels it to seek moisture of any sort or kind, even urine which may have settled into any unevenness of the floor of the sty. Many of the ailing pigs suffer from a dry, husky cough, a gummy discharge exudes from the eyes and forms a ring round them, the ankles become affected, and the muscles of the back become weakened so that the pig has difficulty in walking. The discoloration of the skin may or may not increase, but the weakness gradually becomes greater so that death may follow within a day or two from the first attack. Occasionally the affected pig will continue to live for several days, and eventually recover so much that it can be fatted, but there exists a great risk of the recovered pig being what is termed a "carrier" of the disease, and possessing the ability to infect other pigs with which it may come in close contact, although the germs of the disease which it carries do not affect its own health. Similar instances of human beings being "carriers" of the disease have been recorded. So difficult is it at times to discover the source of the infection of swine fever that certain persons who are not amongst the strongest believers in the practical knowledge of the members of the veterinary profession assert that swine fever need not necessarily be the result of infection, but that injudicious feeding or the neglect of sanitary arrangements will sometimes cause an outbreak. There does not appear to be the slightest ground for this belief, as there is a specific virus which when it obtains ingress into the body of the pig, whether by the mouth, nose, or in any other way, may result in an attack, more or less severe, of swine fever, unless the virus has become so attenuated that it is unable to affect the host sufficiently. This attenuation, which is due to causes which are probably not completely known, is commonly the cause of the absence of further cases of swine fever amongst one of a lot of pigs which has had a very mild attack. This variation in the virulence of