368 PA THOGENIC BA CTERIA. sin i, and phenol 5. After staining they are washed in distilled water containing i per cent, of acetic acid, dehydrated in alcohol, cleared, and mounted. In such preparations the bacilli may be found in little groups, which are easily discovered, under a low power of the microscope, as reddish specks, and readily resolved into bacilli with the high power of the oil-immersion lens. In bacilli stained by this alkaline methylene-blue solu- tion dark-colored dots may sometimes be observed near the ends of the rods. These dots were at first regarded as spores, but are now denominated polar granules, and are thought to be of no importance. The typhoid bacillus is both saprophytic and parasitic. It finds abundant conditions in nature for its growth and development, and, enjoying strong resisting powers, can accommodate itself to environment much better than the majority of pathogenic bacteria, and can be found in water, air, soiled clothing, dust, sewage, milk, etc. con- taminated directly or indirectly by the intestinal dis- charges of diseased persons. The bacillus is also occasionally present upon green vegetables sprinkled with water containing it, and epi- demics are reported in which the infection was traced to oysters, from a certain place where the water was infected through sewage. Newsholme1 found that in 56 cases of typhoid fever about one-third was attributable to the eating of raw shell-fish. In such cases the evidence accumulated serves to show that the shell-fish were from sewage-polluted beds. The bacillus probably enters milk occasionally in water used to dilute it. The resistant powers of the organisms have already been described as great. They can grow well at the room-temperature. The thermal death-point is given by Sternberg as 60° C. The bacilli can, according to Klem- perer and Levy, remain vital for three months in distilled water, though in ordinary water the commoner and more 1 Brit. Med..Jour., Jan., 1895.