1916] S'wezy: Kinetonudcuf: of Flagellates 215 



gest its function as that of an accessory organelle and not tliat of a 

 kinetic center or nucleus. 



2. SECOND LINE-BODONIDAE-TRICHONYMPHIDA 



Starting from a simple, free-living Boclo, the stages of evolution of 

 the parabasal body in another line are equally apparent in an almost 

 orthogenetic series culminating in the elaborate differentiations of the 

 Triehonymphida. Two forms of this structure are found in tlie 

 Bodonidae, one of which is illustrated by Prowazekia cruzi (fig. 20) 

 with the characteristic round parabasal body situated below the 

 lilepharoplast and connected with it by a short rhizoplast. 



The parabasal body of P. cruzi is the only structure in this group 

 which has been recognized by Hartmann as a "kinetonucleus. " A 

 careful study and comparison of the other forms with Prowazekia 

 cruzi will, however, show that no line of distinction can be drawn be- 

 tween them. So far as their morphology, mode of division, apparent 

 origin, and function are concerned, they present similarities too great 

 to admit of any separation being made. 



The second type is that shown in Prowazekia lacertae (Grassi) 

 (figs. 26, 31), a flagellate which differs from the structure in the 

 typical Bodo mainly in the presence of the organelle which I shall 

 here term the parabasal body, regarding it as the homologue of the 

 parabasal body of Prowazekia cruzi and of that of the trypanosomes. 



This small protozoan I have found to be quite common in the 

 amphibians Diemyctylus torosus, Plethodon orcgonensis, and Batra- 

 choseps attenuatus from California. It was described by Prowazek 

 (1904) as Bodo lacertae. This name, however, has been reserved for 

 those flagellates which do not possess a ehromidial body or parabasal 

 body in relation to the nucleomotor apparatus, hence it properly be- 

 longs with the genus Prowazekia. The proposal of Alexeieff (1912) to 

 lay aside the generic term and substitute for it Prowazekella Alex, 

 lacks adequate foundation. In his figures la and b he shows Bodo 

 caudatus, neither figures of which are like the typical Bodo in struc- 

 ture. In figure Ic he portrays Projvazekella (nom. nov.) lacertae, 

 which possesses the structure neither of the typical Bodo nor of 

 Proivazckia. Both of these forms, however, have a parabasal body 

 connected with the blepharoplast, a condition which has not been fig- 

 ured in the common free-living Bodo. 



