154 SOME MINUTE ANIMAL PARASITES 



present, but these do not contract as in the free- 

 living forms, and a large number may be present. 

 Should red blood-corpuscles (Fig. 32, c) be present 

 in the Entamoeba, the action of the latter on them 

 can be seen under the microscope so long as the 

 organism is kept warm. The red corpuscles gradu- 

 ally break up, void their colouring matter, which then 



a. 

 b. 



A. 



B. 



FIG. 32 ENTAMCEBA HISTOLYTICA 



A, B, Two large trophozoites ; a, pseudopodium of clear ecto- 

 plasm ; 6, nucleus of " tetragena " type ; c, ingested red 

 blood-corpuscles ; d, vacuole ; e, crystalloid substance 



becomes somewhat greenish, and gradually disappear, 

 till a " shell " or " ghost " is all that remains to show 

 that they ever existed. 



The methods of multiplication of Entamoeba 

 histolytica used to be considered to be twofold. 

 Simple division occurs just as in E. coli, and as in 

 that organism, is initiated by the division of the 

 nucleus into two equal or almost equal portions. 

 Gemmation or multiplication by bud formation was 



