— .54 — 



each alveole containing a regular, rounded chromatin gra- 

 nule. Lastly, in nuclei that have accidentiy fallen out of the 

 body of Myxornonas in the process of preparation, the intra- 

 nuclear network is often absent. In that case all the interior 

 of the nucleus is occupied by an accumulation of very mi- 

 nute chromatin granules, or the chromatin may be 

 gathered into indistinct threads interlaced together, and 

 resembling the spirem figure. The varieties in the struc- 

 tures of the nucleus described are especially characteristic 

 for individuals taken from smears, and not fixed by means of 

 dropping the contents of the intestine of Hodotermes into the 

 fixing liquid. On account of this, I think it is possible, that 

 this variety partly depends on the rapid changes which take 

 place in the nuclei, when the smears are prepared. 



With the nucleus is closely connected the anterior end of 

 the undulating membrane. The course of the undulating mem- 

 brane may vary greatly, but generally it has a tendency to 

 coil in one plane into a very closely winding spiral surrounding 

 the nucleus. The details in the structure of the undulating- 

 membrane are best to be seen in those rare cases, when it 

 falls out of the body together with the nucleus and axostyle, 

 and straightens out a little (tab. I, fig. 14 & 15). 



The anterior end of the membrane begins somewhat 

 in front of the nucleus and clasps the nucleus from above 

 with its basal portion, like a horse shoe; very often the hor- 

 se-shoe-shaped part of the membrane stains more intensely 

 than the neighbouring parts of it, and has the appearance of 

 an independent formation. Similarly to Gigantomonas the 

 basal portion of the membrane stains with Heidenhain's hae- 

 matoxylin much stronger than its free edge, the border bet- 

 ween the light and dark zones being either very sharply out- 

 lined (tab. 1, fig. 14), or both zones gradually passing one into 

 another (tab. II, fig. 17 & 18). The membrane of Myxomonas 

 is easily distinguishable from that of the preceding genus 

 by the structure of its free exterior edge. It is peculiar to 

 Myxomonas that under the border filament (border flagellum) 

 of the membrane there passes at a close distance a second 

 filament which supports the first. Such additional filaments 

 have been often described in the membranes of Trichomonads. 



The axostyle is well developed. It approaches the nuc- 

 leus from behind and envelopes it with its widened anterior 



