THE PATHOGENIC RHIZOPODA 



301 



gromia. These grow to maturity and form gametes which escape 

 and conjugate in the surrounding water, the resulting copula devel- 

 oping into a biflagellated organism which subsequently becomes 

 ameboid and grows into an adult allogromia (Fig. 116). ^^^lile 

 there is reason to doubt some of the developmental stages of this life 

 history, the essential fact remains that here is a clearly defined rhizopod 



"Allogromia," sp. (After Prandtl.) A, an individual from Ameba proteus with nucleus 

 undergoing fragmentation to form chromidia; B, aggregation of distributed chromatin into 

 secondary nuclei; C, A, Vampyrella, sp., infected with Allogromia, sp.; D, allogromia from 

 Ameba proteus shortly before ripening of the gametes. 



Fig. 117 



Single and multiple infection of ameba nuclei by Nucleophaga amebte. (After P^nard.) 



one stage of whose life history is passed as an intracellular parasite. 

 The history of its nucleus is important as furnishing a po.ssible interpre- 

 tation of the distributed condition of the chromatin in neuroryctes and 

 cytoryctes. The cell plasm of this so-called allogromia becomes filled 

 with idiochromidia which are derived from the nucleus (Fig. 1 16, A, B). 

 It is probable, as Doflein points out, that this organism is not an 



