viii, B, 6 Schobl: Plague in Manila in 1912 417 



of whether or not plague can be transmitted by fleas, since the 

 question has been conclusively answered by the work of the 

 Indian Commission, nevertheless the following observations of a 

 small outbreak of plague among animals, the spreading of which 

 was due solely to fleas, are of interest. 



One wild rat was inoculated with strain Iloilo 3 of Bacillus 

 pestis. The skin adjoining the root of the right ear was scarified, 

 and a loopful of the culture was smeared on the scarified skin. 

 The rat was found dead three days after the inoculation. 



The cage containing the dead rat was immersed in kreolin 

 solution. At autopsy the cervical glands were found slightly 

 swollen, somewhat reddened, but no hsemorrhagic oedema of the 

 surrounding tissue was noticeable. There was slight necrosis 

 at the place of inoculation, showing superficial, purulent dis- 

 charge. Clear effusion in both pleural cavities and one haemor- 

 rhage in the pleura were found. The lungs were hyperaemic, 

 but otherwise normal. The spleen was of somewhat darker 

 color, but otherwise normal in size and appearance. The liver 

 showed a slight degree of parenchymatous degeneration, the 

 congestion making prominent the structure of the organ. The 

 typical, although not constant, changes of the organ, which 

 are characteristic of natural plague infection in rats, were 

 absent. The kidneys were without macroscopic change. The 

 lymph glands, with exception of the cervical nodes, were normal. 



Examination of the rat's fur revealed ectoparasites on the 

 neck, under the chin, and back of the ears; these at the time 

 of the examination apparently were dead. About 6 common rat 

 fleas were found and identified as Lcemopsylla cheopis Rothsch. 

 The parasites were immersed in sterile salt solution for three 

 hours. When removed in a dry test tube, they began to move 

 about sluggishly. The intestinal tract of these fleas contained 

 blood. 



Five of the fleas were crushed by means of sterile forceps, 

 and inserted in' a pocket under the shaved skin of a guinea pig. 

 The animal died of plague within three days, showing consider- 

 able haemorrhagic oedema around the place of inoculation, typical 

 bilateral inguinal buboes, and characteristic changes in the 

 spleen. Smears and cultures made from the bubo and spleen 

 were positive for Bacillus pestis. 



Another wild rat, which was in a separate cage in the same 

 room where rat 1 had been kept, died twenty-four hours after 

 rat 1. The two cages were at least 10 centimeters apart. Rat 

 2 harbored fleas of the same species as were found on rat 1. 



