Just as before an epidemic of cholera visits a place, it is usual to observe cases of mild diarrhoea, and indigestion prevailing amongst its population; so, before plague actually breaks out, it has been found that cases of buboes and parotites with fever are commonly observed. Such cases were called Pestis Minor at Astrakhan. “No one died from the disease per se, but few people were confined to bed.” It is not known whether in pestis minor the plague germs could be found; but presumably not.

Drs. Simpson and Cobb of Calcutta have described what is called Pestis Ambulans, or an ambulatory form of plague, in which plague germs have been found. The commonly accepted types of plague are (1) Fulminant; (2) Typical; (3) Pestis Minor (including ambulans). The cause of the first two is the bacillus discovered by Kitasato, and they are very fatal, of the third, the cause may be an allied bacterium less potent to produce toxic effects on man, and it may come and go but plague may not break out. In ambulatory form the patient has slight fever and glandular enlargement, but he can move about.