vn] FLEAS AND PLAGUE 85 



that bacilli are scarcely ever found in the blood in 

 bubonic cases that the invaders are stopped by the 

 lymphatic glands next above the point of inoculation. 

 In such cases the fight, which is the illness, takes 

 place chiefly in the bubo. In non-bubonic cases the 

 fight goes on in the blood-vessels or in the lungs as 

 the case may be. 



Whether the plague is primarily a disease of rats 

 would be difficult to say ; but rats and other rodents 

 are very susceptible to it. It has also been trans- 

 ferred to mice, rabbits, guinea-pigs, squirrels, pigs, 

 sheep, goats, cattle and horses. Men and monkeys 

 are equally susceptible. Cats and dogs have been 

 known to die of it and during the Great Plague of 

 London many were destroyed under the belief that 

 they were bearers of infection. 



That plague among human beings was associated 

 with mortality among rats and mice, is an observation 

 of great antiquity. The student of the Hebrew 

 scriptures will remember the Book of I Samuel vi. 4 : 

 " Then said they, What shall be the trespass offering 

 which we shall return to him ? They answered, Five 

 golden emerods [buboes] and five golden mice [rats] 

 according to the number of the lords of the Philistines : 

 for one plague was on you all and on your lords." 



Eastern authors, of a later date, refer in several 

 places to rats, in times of plague, staggering about 

 as though they were drunk. The Mogul Emperor 



