118 BACTERIOLOGY. 



both forms are difficult to cultivate, the diagnosis must 

 be made by examining smears made directly from the 

 throat. These organisms may be present with the 

 bacilli of true diphtheria, and are said to aggravate 

 the infection. (See Fig. n, page 89.) 



The disease is usually mild and responds fairly 

 promptly to local treatment, but in some cases where 

 the nature of the infection has not been recognized and 

 properly treated, the ulceration and destruction of 

 tissue in the throat may be extensive. It is spread 

 directly from person to person through the secretions 

 from the mouth. The danger o>f becoming infected 

 is not great. 



MALARIAL FEVER. 



Malarial fever is an acute infection caused by a 

 protozoan parasite. It is characterized by intermit- 

 tent chills and fever and sweats, and accompanied by 

 anemia. There are three types of the fever caused by 

 three species of the parasite : the tertian type, with 

 chill and fever every third day; the quartan, with 

 chill and fever every fourth day; and the estivo- 

 autumnal, with an irregular fever like typhoid. 



The disease is transmitted from one person 

 to another by the female mosquito of the genus 

 Anopheles. They can be distinguished from the ordi- 

 nary mosquito, the Culex, by their position when they 

 alight. The body of the Culex is always parallel to 

 the surface, while the body of the Anopheles forms a 

 sharp angle with it. When the Anopheles feeds on 



