鼠疫是老鼠的病。鼠疫杆菌籍著跳蚤由老鼠传给老鼠,又由老鼠传给人,人得了这病以后又可以彼此传染。传染的方法有两个。第—个方法是籍跳蚤传染,无论是跳蚤由老鼠把这病传染到人,或是由人把这病再传染到另一个人,都是因为跳蚤咬人的时候鼠疫杆菌由跳蚤的口里注射到人的皮内而受传染的。这些鼠疫杆菌到了皮内就进入淋巴管,再从淋巴管进入淋巴腺,这时淋巴腺就肿大,若是淋巴腺的杀菌 The plague is a disease of rats. The fleas from the plague group were passed from rats to mice and from rats to humans. After they acquired the disease, they could also infect each other. There are two ways to infect. The first method is based on a fleas infection. Whether the fleas are transmitted from the mice to humans by the fleas or if the flu is transmitted from one person to another, it is because the fleas bite the fleas from the mouth of the fleas. Infected by injection into human skin. These plague bacillus into the skin to enter the lymphatic vessels, and then from the lymphatic vessels into the lymph gland, when the lymph gland swelling, if the lymph gland sterilization