THE WEB OF LIFE 



363 



FiQ. 57. — ^A common mosquito, Anopheles maoulipennis (female), 

 which carries the Protozoon causing malaria. {After NuttaU.) 



coincidence. Avicenna refers to it in connexion with a 

 plague in Mesopotamia about a.d. 1000. But the identity 

 of the diseases in rat and man was not estabUshed till 

 1894, when the Bacillus festis was discovered by Yersin and 

 Eatasato. This bacillus is a minute rod-like body with 

 rounded ends, about g-gV^ of an inch in length. It is fatal 

 not only to man, but to rats, mice, guinea-pigs, rabbits, 

 hares, ferrets, cats, monkeys, and American ground 



