TRICHOMONAD FLAGELLATES. 351 



tion of micro- and macrogamete. However, in the light of the intense 

 activity of the living forms at this stage it must be regarded only as a 

 chance phase of contraction without morphological meaning. 



Multiple Mitosis in Eutrichommtix scrpeniis. 



We have found e\idence for the occurrence of this phase in Eutricho- 

 monas from both Crofalus and Pifuophis, and our series of stages is 

 incomplete only in the disintegrative phase. The material is appar- 

 ently normal in all cases and was found in but a single host in each 

 species. 



The formative phase of the plasmodium or somatella is fully repre- 

 sented (PI. 8, Figs. 9S-100). We find no means of distinguishing 

 ordinary binary fission from the initial division which is followed 

 in multiple fission by the two succeeding synchronous mitoses. There- 

 fore any binary fission may supposedly serve as illustration of the first 

 division in multiple mitosis (PI. 7). 



The second mitosis in multiple fission (PI. 8, Figs. 98, 99) is syn- 

 chronous in both nuclei resulting from the first mitosis. That this 

 4-nucleate phase is thus formed is shown by the persisting plasmo- 

 desmose (Figs. 98, 99) joining the sister nuclei. The number of chro- 

 mosomes in the nuclei of the plasmodium is four (PI. 8, Figs. 98, 99), 

 the same as in l)inary fission. The plasmodium is therefore not in a 

 diploid and the trophozoite in a haploid condition. 



The derivation of the 8-nucleate plasmodium from the 4-nucleate 

 is shown (PI. 8, Fig. 100) by the four paradesmoses which join the 

 sister nuclei derived from the four of the preceding stage. 



It is difficult if not impossible to follow the history of the extra- 

 nuclear organelles din-ing the formative phases of the somatella. Ihe 

 ultimate formation of the full complement is indicated by their pres- 

 ence in the later disintegrative phases (PI. 8, Fig. 103). There is 

 some evidence that the multiplication of axostyles is delayed in mul- 

 tiple fission as in binary'. There are apparently eight cytostomes and 

 four axostyles in the 8-nucleate plasmodium shown in Plate 8, Figure 

 100, but not as yet the full complement of flagella. 



We have no evidence as to the duration of any of the plasmodial 

 stages. W^e do not find more than eight nuclei and the 8-nucleate 

 Plasmodium disintegrates by the successive detachment of the single 

 component merozoites. There is no evidence of a regular plasmo- 

 tomy to 4- and 2-nucleate plasmodia reversing the order of the forma- 



