1916] 8wezy: KinetoiiHclcus of Flagellates 203 



these days, and yet it is frequently disregarded, as in the present 

 instance, where the haemogregarines are considered closely related to 

 the haemoflagellates. 



Among the Piroplasmida and Plasmodiidae even less foundation 

 can be found to support the claims for a binuclear condition. In one 

 form, at least, of this group the life-cycle has been worked out with a 

 fair degree of accuracy and thorouglmess, by a number of investi- 

 gators whose results correspond iu all essential details. I refer to the 

 well-known life-cycle of the malarial parasite. The general concur- 

 rence of opinion among the majority of investigators leaves no doubt 

 as to the non-occurrence of a flagellate stage in these forms. Hart- 

 mann (1907) figures such a stage in Proteosoma. Attention must be 

 called to the striking resemblance between his figure and that given 

 by Neumann (1908, pi. 5, fig. 51), which the latter interprets as the 

 fertilization of the macrogamete by the microgamete. An examina- 

 tion of Neumann's other figures bears out this interpretation. Pos- 

 sibly the form figured by Hartmann represents the same process. 



The heteropole division of the nucleus to form the parabasal body 

 in Plasmodium from the monkey, as figured by Berenberg-Gossler 

 (1909), is a very far-fetched interpretation of facts. His figures 12 

 and 13, plate 16, are shown as the building of the "Nebenkern," a 

 structure which, judging from his figures, the organism possesses only 

 in this, the dividing state. These figures differ in no essential details 

 from figures 14 and 17 on the same plate, which he interprets as 

 division of the nucleiis, and which do not show the presence of the 

 previously divided-off parabasal body. In fact, this latter structure 

 ceases to exist, apparently, after it has been formed by an unequal 

 division of the micleus. The division of the nucleus in figure 17 is 

 also unequal, but in both cases there seems to be an equal distribution 

 of the chromatin material. 



The interpretation of this granule as the parabasal body seems to 

 rest solely on the fact that it is formed, apparently, by an unequal 

 division of the nucleus. It does not appear in the stages immediately 

 following this, where the nuclei divide several times in the process 

 of schizogony. This would strongly suggest, if these were actually 

 successive stages, that the granule in question was merely a bit of 

 extruded chromatin which later disappeared in the cytoplasm. At any 

 rate, Berenberg-Gossler 's figures prove that a parabasal body is not 

 a permanent cell structure in this species of Plasmodium and that it 

 is not even found constantly in any one stage of the life-cycle. 



