1916] 



Sirczif: Kincffiintch us of Flagellates 



22:? 



With these comparisons in mind the conclusion seems inevitable 

 that the parabasal body of Trypanoplasma has its homologue in the 

 "ehromidial body" of Polymastix hufonis, morphologically and func- 

 tionally equivalent to it. This must therefore be considered the para- 

 basal body of that species. That the backward migration of the para- 

 basal body carries the blepharoplast with it in the haemofiagellates 

 does not invalidate the homology here, as these structures are still 

 connected by a rhizoplast, and hence the parabasal body still preserves 

 its function, as an accessory kinetic reservoir. 



Fig. 58. Trichomonas (iKijiitita Alexeieff. X 2000. Normal active tropho- 

 zoite, showing nucleus, axostyle, blepharoplast, parabasal body, uuilulating 

 membrane and flagella. 



A further step in the evolution of this structure is that exhibited in 

 some of the trichomonads, in the presence of the chromatic basal rod. 

 A full discussion of the morphology and relations of this organelle has 

 been given elsewhere (Kofoid and Swezy, 19156) and need not be 

 repeated here. 



The difficulties of hoiuologizing a structure like the chromatic 

 basal rod of Trichomonas augusta (fig. 58) with the parabasal body 

 of the trypanosomes are considerably lessened when we regard the 

 intermediate form, Prowazekia lacertae, as the connecting link. The 

 long, ribbon-like parabasal body of the latter species, with its deep 

 intra-cytoplasmie position and rhizoplast connecting it with the 



