352 KOFOID AND SWEZY. 



live steps. Plasmodia with six (PI. 8, Fig. 102) and with 3 (PI. 8, 

 Fig. 103) nuclei have been found. It is impossible to distinguish 

 binucleate plasmodia (PI. 8, Fig. 104) of the disintegrative phase of 

 multiple fission from late phases of binary fission. 



No evidence appears to indicate that the component merozoites 

 have any fixed relations in the somatella or any order of succession in 

 detachment. The position of the daughter nuclei in parallel rows in 

 one Plasmodium (PI. 8, Fig. 98) and at right angles in another (PI. 8, 

 Fig. 99) and the great mobility of the component merozoites noted 

 in the multinucleate plasmodium of Trichomonas augusta (see text 

 figure G) render any constant morphological relations of the compo- 

 nent units of the somatella very improbable. 



Discussion of Multiple Mitosis. 



The occurrence of multinucleate forms in the life-history of tricho- 

 monads has been fragmentarily obser\ed by several prior investigators 

 of these flagellates though none has indicated the range and signifi- 

 cance of the phenomenon. 



Marchand (1894) noted without comment the occurrence in Tricho- 

 monas vaginalis of very large individuals with more than two nuclei 

 but does not state the number. He finds in preparation a stainable 

 thread joining the nuclei in pairs and the presence of flagella with 

 each nucleus. He thus evidently had the formative phases of the 

 Plasmodium under observation. His single figure (1894, pi. 3, fig. 18) 

 shows a 4-nucleate plasmodium with the paradesmose joining two of 

 the nuclei. Another figure (his pi. 3, fig. 7) might be interpreted 

 as a disintegrative phase in the binucleate stage with the last plasmo- 

 desmose just retreating into the common mass of cytoplasm. 



Prowazek (1904) figures as a " Teilungstadien " of Trichomonas 

 lacertae a single 3-nucleate plasmodium with a still persisting plasmo- 

 desmose, and the same three hours later with one merozoite nearly 

 detached. He merely notes in passing the prolonged process of plas- 

 motomy and the fully developed organelles of the three individuals. 

 He presents no data as to the method of their origin or dispersal, but 

 designates the instance as one of " gleichzeitig erfolgende Mehrfach- 

 teilung." It is evident that his own data do not justify the adjective 

 "gleichzeitig" nor do our observations of a progressive dispersal con- 

 firm it. 



Dobell (1907, PI. 27, Fig. 14) records for Trichomastix scrpentis 



