The celebrated epidemics of Hendon and Wimbledon were believed by Dr. Klein to be due to scarlet fever in the cows, but this belief has not been stantiated. It is probable that the ease from which those cows suffered was not true scarlet fever. The disease has been conveyed by letters written by hands in the stage of desquamation. An at tendant upon a case of scarlet fever may easily carry the infection to other chil dren by the cloths, hands, or beard.
Report of a remarkable instance of the participation of swine in an out break of scarlatina in Germany. While the children at a number of farm-houses and cottages were suffering from scar latina of a severe type, the pigs were attacked by a highly infectious and fatal fever, the symptoms and post-mortem ap pearances of which were identical with those of scarlatina in man, viz.: angina, erythema, followed, in those that re covered, by desquamation, oedema of the extremities, albuminuria, urmmia, and acute nephritis. A healthy animal at a house where none of the family had been attacked, having been inoculated with the blood of a child suffering from scar let fever, died at the end of a week with symptoms and lesions indistinguishable from those of the human disease and from those of the pigs that had presum ably contracted it from the inhabitants. Behle (Brit. Med. Jour., Jan. 2S, '99).
Streptococci always found in the tis sues and blood of scarlatinal cases. In not one of the many cases investigated at necropsy were the streptococci absent from the cardiac blood and the bone marrow. Cultures taken from the mem brane of patients with searlatinal angina showed streptococci, admixed with pneu mococci, leptothrix, etc.; in only 5
per cent. of the cases were they asso ciated with the Klebs-L5ftler As to their morphology, which is of a distinctive character, the streptococci form chains of varying length. The single coccus is round, but frequently is flattened at right angles to the axis of the chain; examined closely it often resembles a diplococcus, but its mor phology is subject to considerable varia tion. When subjected to the action of blood taken from patients convalescing from scarlatina, these streptococci failed in every instance to give the agglutina tion reaction. Baginsky and Sommer feld (Archie fiir Kinderh., .Tan.. 1902).
The portal of entrance in most cases is undoubtedly the naso-pharynx. It is here that the first local symptoms appear, and all the evidence points to the fact that both the primary and secondary micro-organisms commonly enter the system at this point.
In cities scarlet fever is endemic, a few cases appearing in the health reports every week, but at intervals it becomes epidemic, usually during the fall and winter. Epidemics of scarlet fever usu ally spread very slowly as compared with those of measles.
—The period of incubation is shorter than that of any other infectious disease, except, perhaps, grippe and diphtheria. The extremes range from a few hours to fifteen days. In 87 per cent. of cases Holt found the period to be less than six days and in 66 per cent. between two and three days.