55 



end in the shape of a thin film, and lioconK'.N CDiuicrUMl wiili 

 the horse-slioo-shapod base of \hv nicnibriMio, whicli is attu- 

 rlnul to tln^ nucleus in front, as wo havo seon. Tho hest evi- 

 dence as to the close connection between the luiclcus, mem- 

 brane and axostyle Is borne by the fact that in the process 

 of preparinj^' the sin(\irs these or^'anella may i>e easily remo- 

 ved out of the body, without, however, becoming- disconncc- 

 teii (see fii;- 14 \- 15, tab. I.) The axostyle consists of a 

 lighter peri|.theral layer, like an integument, and a l)lack axis 

 (after staining with Heideiihaiu's haematoxyliii). The axostyle 

 of Mj/d'o/iiofias has an important peculiarity in that it lies 

 entirely inside tln' body of the animal, without projecting 

 outside, and witlioiit forming the caudal spine, as it is usual 

 ill the Trichomonads. Leaving the nucleus, the axostyle runs 

 to the posterior (MkI of the body, l)nt here it meets with the 

 compact ectoplasm, bends again forwards and forms a greater 

 or smaller arch; very often the posterior end of the axostyle 

 bends forwards so much, that it nearly touches the nucleus 

 (such cases are especially numerous in specimens, in which 

 the undulating membrane is coiled around the nucleus in 

 one plane into a very winding spiral). It is very difficult to 

 decide how the axostyle terminates at its anterior end. Only 

 in one specimen of Miixomonas, in ^vhich the apparatus was 

 separated, I saw distinctly that the external covering (integu- 

 ment) of the axostyle after surrounding the nucleus has for- 

 med on its surface a clearly visible knob (basal body?). 



The axostyle presents an elastic rod which is in the state 

 of tension; this is clearly seen from the fact that, when remo- 

 ved out of the body of Myxomonas, the axostyle straightens 

 like an arrow (tab. I, fig. 14, 15). It is clear that both the 

 axostyle, and the undulating membrane play an important 

 role in giving the shape of body to Mijxomonas. 



The axostyle on one hand, and the membrane and ecto- 

 plasm on the other, act as antagonists. The axostyle has a 

 tendency to straighten and, thus, helps to stretch the body 

 longitudinally.The undulating membrane tends to coil into a 

 spiral lying in one plane (nearly perpendicular to the axis 

 of the axostyle) at the anterior end of the body; and as the 

 membrane lies in the ectoplasm and is closely connected 

 with it, it draws the ectoplasmatic sac to the anterior end 

 when it contracts, and in this way it makes the posterior end 



10* 



