The Mastigophora 163 



colorless species (240). A palmella is dominant in the cycle of Eugleno- 

 capsa ochracea (263), and a sessile non-flagellated stage plays a compa- 

 rable role in Colacium vesicidosum (Fig. 4. 35, O, P). The sessile stage of 

 the latter is derived from a flagellate which becomes attached at its flag- 

 ellar end. The flagellum and reservoir disappear, a sheath and stalk are 

 secreted, and mitosis may produce as many as eight nuclei. A naked 



Fig. 4. 34. A-D. Euglena: E. gracilis Klebs (A), xl200; E. sociabilis Dan- 

 geard (B), x450; E. pisciformis Klebs (C), xl650; E. tripteris (D), x475 (after 

 Johnson). E. Eutreptiella marina da Cunha. xl600 approx. (afte; da C). F. 

 Trachelomonas hystrix, test only; x600 (after Dangeard). G. Euglena oxyu- 

 ris Schmarda, x350 (after Johnson). H. Phacus p\rum, showing two large 

 lateral paramylum bodies, small discoid chromatophores, nucleus (in out- 

 line); xl750 (after Krichenbauer). I, J. Phacus quinquenwrginatus Jahn and 

 Shawhan, surface and anterior views; length, 35-52/^; schematic (after Allegre 

 and Jahn). K, L. Phacus torta Lemmermann, broad sinface and anterior 

 end; length, 80-100/^; schematic (after Allegre and Jahn). 



