CELL DIVISION AND THE FORMATION OF PARAMYLON 

 IN EUGLENA OXYURIS SCHMARDA. 



L. B. Waltox. 



The method of reproduction in Euglena oxyuris Schmarda 

 has not been observed, while the characteristic manner and 

 the time element involved in the formation of the constituent 

 parts of the cell is also of some interest. Therefore, the following 

 notes made in connection with some uncompleted studies on the 

 life cycle of Euglena are presented. 



Of the forty or more species constituting the genus, E. oxyuris 

 Schmarda is by far the largest, often attaining a length of approxi- 

 mately 500/A. In the study mentioned, several of the smaller 

 species of Euglena had been obser^^ed by the writer, to encyst and 

 after repeated divisions pass through an apparent sexual stage, 

 in consequence of which it was desirable to check the results with 

 a larger form, permanent preparations of which could be more 

 easily made. Therefore, several specimens of E. oxyuris were 

 transferred from a culture to a lens paper aquarium, the margins 

 of which were closed by paraffin oil to prevent evaporation and 

 placed under observation, Feb. -i, 1906. No reproductive pro- 

 cesses similar to those in the smaller species mentioned were 

 observed, but several in the process of division were noted and 

 studied with the 1-12 immersion objective. The characteristic 

 organs of the species (Fig. 1, A) are the oval nticleus (n), the 

 large anterior (p^) and posterior (p^) paramylon granules, the 

 stigma (s), reservoir (r), pharynx (p) and chloroleucites (c). 

 The figures are all based on camera lucida drawings. 



On Feb. 6, at 10:03 A. M., a single individual (Fig. 1, B) was 

 observed much broader anteriorly than the normal form and in 

 which the nucleus had approached the stigma while the anterior 

 paramylon granule occupied very nearly the nonnal position 

 of the nucleus. It was not until i:45 P. M. (Fig. 1, C) that the 

 division of the stigma was observed, the nucleus in the meantime 

 having become obliquely elongated, and the anterior param^don 

 granule having moved down to a position beside the posterior 

 granule. At 3:35 P. M. (Fig. 1, D) division had so far progressed 

 that the anterior fourth of the individual — individuals? — were 

 separated, the two nuclei being almost distinct. At 4:15 P. M. 

 (Fig. 1, E) longitudinal division was nearly complete and the 

 two nuclei were moving slowly posteriorly to their normal position. 

 At the same time a peculiar phenomenon was taking place in 

 connection with the two paramylon granules. The protoplasm 

 containing the granule of the individual on the left would rapidly 

 flow posteriorly, so that the granule was actually in the posterior 

 end of the individual on the right as indicated by the solid arrow. 



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