=Flies as Bearers of Disease.=--In estimating the relative importance of flies and water supply in spreading disease, Dr. M. A. Veeder distinguishes between intestinal and malarial disorders. In the former the infection is a bacillus of some sort, the presence of which can be traced to contamination by excretions from a diseased bowel. In the latter the source of infection is peculiar to marshy or stagnant water, and independent of contamination from human sources. It is the author's belief that, with relatively unimportant exceptions, intestinal diseases are spread almost exclusively by flies and malarial diseases by water, and he supports it by citations from recent army experiences. Likewise, during the recent British campaign in Fashoda, which was most carefully planned and took place in a climate that is exceptionally dry and hygienic, there was no abatement of typhoid fever. In the case of an outbreak of malignant dysentery described by the author in a previous paper, taken at its height, not a new case occurred after measures were adopted that made conveyance by flies impossible, although there had been fresh ones every day for some time previously. Another more recent "lively epidemic" of typhoid mentioned by the author was ended in a day by measures directed against conveyance by water. "When flies are responsible, there are little neighborhood epidemics, extending in short leaps from house to house, without reference to water supply or anything else in common. But when water is at fault the disease follows its use wherever it may go.... Epidemics spread by flies tend to follow the direction of prevailing warm winds, as though the fly, wandering outdoors after contact with the source of infection, had drifted with the wind, but nothing of the sort is perceptible in the case of water-borne disease."