HISTORICAL. 



11 



the observation of Lambl of an organism of this 

 nature in the intestinal discharges of a case suffering 

 from diarrhoeal disease. In fact, it may be said that 

 almost all of our exact knowledge concerning the 

 specific differentiation of these parasites dates from 

 the paper of Schaudinn published in 1908, and that 

 greater advance has been made during the past seven 

 years than in the forty-three years preceding. At 

 the present time it is definitely established that several 

 species of amoeba are parasitic in man, that some of 

 them are capable of producing typical pathological 

 lesions, and that it is possible to produce similar 

 lesions in some of the lower animals by the feeding 

 or injection of material containing these parasites. 

 In addition the entire life cycle of several of the 

 species has been worked out and the differentiation 

 of these species is based upon the life cycle as well 

 as upon definite morphological characteristics. 



In the succeeding pages, under the appropriate 

 headings, further historical details will be given con- 

 cerning each species. 



