PROTOZOA AND DISEASE 



PART II 

 CHAPTER I 



INTRODUCTORY 



FOUR years ago, when the first part of this work appeared, important 

 advances had been made in our knowledge of the Sporozoa. Among 

 these advances the discovery of the sexual phase was then still 

 recent, and the relationship of the hsematozoa of malaria to the 

 coccidia had only just been established. 



In the interval progress 1 has been most marked in respect of 

 another class of the protozoa, the Flagellata. The most striking and 

 important of these advances in our knowledge of the causes of 

 disease will be outlined in the following pages, and the state of 

 knowledge in regard to other diseases suspected of being caused by 

 protozoa will be indicated. 



In this introductory chapter the first place will be given to a 

 brief study of some non-parasitic protozoa, because it is only by 

 being familiar with such forms that we can hope to recognise and 



1 No one can think of this progress in protozoology without recalling the names 

 of two investigators J. E, Dutton and Fritz Schaudinn who lost their lives from 

 infection contracted whilst studying the sphere of protozoa in the causation of 

 disease. Dutton was the first to give us a detailed account of a case of human 

 trypanosomiasis. Schaudinn's many brilliant contributions to protozoology mark 

 an epoch in the science. Some of his work on the htemoflagellates of birds, and 

 his discovery of the spirochasta or spironema of syphilis, and others of his contribu- 

 tions to protozoology, will be referred to below. 



I 



