68 



division of the nuclei takes its normal oours^^, so that it 

 leades to the formation of mu ltinuc lear , abnormally 

 large cells. 



("^0) Mgelil found a cell with tv;o nuclei in a filament 



°^ Spirogyra orthospira '^ay'S-pi ralisj^ it was tv^ice as long 

 as the normal cell. Recently v. Wissenlingh^, who "brought 

 half spoiled cultures of Spirof^-yra triformis to renewed 

 luxuriant development, observed multinuclear cells in all 

 the filaments of the new cultures, (Compare fig. 14,) 

 The formation of cross-walls was dither suppressed entire- 

 ly, or only incomplete, rigg-like walls, or V7c,lls formed 

 only on one side v/ere produced, (Pig. 14, below,) The 

 cells contained S, 3, 4, and 8 nuclei. In the multinuclear 

 cells V, Msselingh measured an average length of 397 ♦B u. 

 in the largest among them 450 and 455 u, "Yet this length 

 is comparatively small. It is less than three times the 

 medium length of the uninuclear cells". It is not pos- 

 sible fq state in detail what conditions were decisive 

 for the production of the abnormally large cells in v. Wis- 

 selingh's experiments. 



Gerassimoff obtained results similar to those of v. 

 Wisselingh in the use of lower temperatures and by. treat- 

 ment with poisons (Chloral hydrate, ether, chloroform). 

 The variation from the normal consisted in the fact that 

 a cell with no nucleus and one with two nuclei were pro- 

 -duoed from an uni«-nuclear cell by-division, or the new 

 cross-wall remained incomplete and divised the cell into 

 the two communicated^ chambers, 



■ The production of the multinuclear spirogyra cells 

 corresponds in all essential points with the formation of 

 the "long rods", which Hansen has described for Bacterium 

 Pasteurianum^ g On double beer in a temperature of five de- 

 grees to perhaps 34 degrees C, the bacteriiim appears in 

 its "normal"form : there develop short rods, 2 u« long, 

 1 u. wide, united in chains. If the culture of the short 



1. Pfianzenphys. Unters., 1885, Heft. I, p. 43, 



2. Ueber mehrkernige Spirogyrazellen, Flora, 1900, 

 Bd., LXXXVII, p. 378. 



3. Gerassimoff. Ueber di^ kernlosen 2ellen bei einigen 

 Konjugaten. Lull. Soc. Imp. Hatur. Moscou,1892,p.l40,Ueb. ein 

 Verfahren,kernlose Zellen zu erhalten(Zur phys.d.Zelle) .Ibid. 

 1896,. Further statements also concerning multinuclear cells 

 and cells v;ithout nuclei in de Bary (Konjugaten 1858 ,p. 2) and 

 Strasburger (Zellbiiding und Zellteilung,3 ,Aufl.l880,p.l84.) 



4. Rech.s.l.bacteries acetif antes, Travaux du labor, do 

 Carlsberg,1894, Vol. III. 



