CELL DIVISION AND THE FORMATION OF 



PARAMYLON IN EUGLENA OXYURIS 



SCHMARDA^'- 



The method of reproduction in Eiiglena 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 approximately 500/a. In the study mentioned, 

 several of the smaller species of Euglena had been observed 

 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. 4, 1906. 

 No reproductive processes similar to those in the smaller 

 species mentioned were observed, but several in the proc- 

 ess of division were noted and studied with the 1-12 

 immersion objective. The characteristic organs of the 

 species are the oval nucleus, the large anterior and poster- 

 ior paramylon granules, the stigma, reservoir, pharynx 

 and chloroleucites. The figures are all based on camera 

 lucida drawings. 



On Feb. 6, at 10:03 A. M., a single individual 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 



*Reprinted from The Ohio Naturalist, vol. 15 (1915), pp. 449-451. 



