306 PARASITIC PROTOZOA IN RELATION TO i HE WAR. 



while pig's should be confined, and not allowed to run in yards 

 and dwellings. In 1915. when in England, I wrote: " As swine- 

 herding is an important occupation in Serbia, the possibility of 

 balantidial dysentery among troops operating in that country 

 must be borne in mind." Afterwards, in 1916, I foimd a few 

 such cases in Macedonia. 



With regard to treatment, thymol has been well recom- 

 mended. 



Blood Protozoa. 



Protozoa, parasitic in the blood, have caused much illness 

 among soldiers in certain theatres of war. I personally had 

 much experience in the diagnosis of blood parasites, especially 

 malaria, not only in England, but in Egypt, Salonika, and Malta, 

 and still more recently in South Africa. The organisms respon- 

 sible for malaria and relapsing fever, as well as trypanosomes 

 that may infect man and transport animals, are included among 

 the blood parasites or H^emoprotozoa. 



Insects serve as the chief transmitters of protozoal diseases 

 of the blood. Thus, the various forms of malaria are carried 

 from man to man by certain mosquitos belonging to the Anophe- 



Fig. 14. Fig. 15. 



Hnse. Lice are responsible for the transmission of some forms 

 of relapsing fever, while ticks (which belong to the Arachnida, 

 another group of the Arthropoda) are responsible for the 

 spread of other forms of human spirochsetosis. 



Blood Flagellates. 



The parasites of the two forms of human sleeping sickness, 

 Trypanosoma gambiensc and T. rhodesiensc (with a posterior 

 nucleus in some of its stout forms), are transmitted by tsetse 

 flies, Glossina palpalis and G. morsitans respectively. T. brucei, 

 the causal agent of nagana, which is often fatal to transport 

 animals, is transmitted by G. morsitans. 



Trypanosomes, whether of man or animals, possess an elon- 

 gate, snake-like or sinuous body. There is a principal nucleus, 

 and a second chromatin body, usually 'barlike, the blepharoplast. 

 The blepharoplast is at the posterior end of the body, and from 

 its vicinity a single flagellum arises, which passes over the body 

 and forms the edge of the locomotor organ, the undulating 

 membrane, bevond which the flagellum is continued for a varying 

 distance as a free flagellum (Fig. 14). Trypanosomes multiply 



