200 RESEARCH IN PROTOZOOLOGY 



influenced by certain conditions of culture. This is also an in- 

 teresting question. Un weaned kittens and older cats are refractory 

 to infection but the causes of the phenomena are unknown. The 

 general opinion of pathologists is that amoebse do not call forth 

 the typical inflammatory reaction of the host, but this opinion 

 requires further investigation. Careful records of the number and 

 relative proportions of the blood cells in amoebiasis are needed. 

 Histological studies of secondary liver lesions in kittens will yield 

 interesting results. The study of amoebiasis may also yield funda- 

 mental information concerning the origin and causes of patho- 

 genicity. Very little is known about this subject in the fields of 

 bacteriology, protozoology or helminthology. Why is it that many 

 parasites live within the host without apparent injury to the latter 

 while others produce disorders that may lead to death ? An amoeba 

 unlike a bacterium has an organization that may be studied 

 microscopically. The fruits of research in histology and cytology 

 may be applied. Therefore there is a bright future for work in 

 experimental amoebiasis when healthy kittens may be always avail- 

 able and all stages in the life cycle of the parasites are obtainable 

 in cultures. 



