1922] Kofoid-Swczy: Mitosis and Fission in G-iardia enter ica 223 



The morphological differences here noted justify the specific dis- 

 tinction of these parasites and raise the question as to the extent, if 

 any, to which the rodent hasts of other species than G. enterica can 

 normally serve as carriers and disseminators of the human parasite. 

 "We regard Deschien's (1921) conclusion that Giardia muris and G. 

 enteric-a are identical species as unsupported by the evidence presented 

 and his morphological analysis as quite inadequate. 



It is highly desirable that experiment should determine the extent 

 to which transfer of species among these hosts is feasible and permanent 

 and that the effect of the new hosts upon the structures of the parasites 

 above enumerated should be carefully analyzed before final conclusions 

 as to the status of these species be drawn. The morphological evidence 

 clearly indicates their specific distinction. The status of cross immuni- 

 ties, if anv exist, .sliould also be determined. 



