^'2Q c- ishikaWa. 



connected with tlie cliroinosoines. But there is seen ;it this stage 

 another set of tihres running from the centre of the nrchoplasm to the 

 polar ends of the chroniosotnes. This structure of the spindle corres- 

 ponds exactly with that of the spermatocyte of Salamandra macu- 

 la ta, as investigated hy Henna nu, with only the difference of the 

 persistence of the nuclear wall in Noctiluca. and tlie necessary 

 modification in consequence of this tact. The optical appearance 

 of these two kinds of fil)res is different, just as in Salamandra. 



13) 1 besides these two sels of fihres, the I eiiundungsfäden are clear- 

 Iv to he recognised extendini»- hetween the separating' chromosomes. 



14) The central spindle fihres originate from the archoplasm, 

 the radial fihres probahly from both the cyto- and nucleo-plasms, and 

 the VerhiinhuKisfäden from the //'/////-substance. 



15) In the spore-buds the archoj)lasm is to be seen lying close 

 to the nucleus u]) to the time of tlie full development of the sj)ore 

 just l)efore its detachment from the mother animaJ, and a part of it 

 l)ecomes transformed into the flagellinn, just as iji many vegetable 

 swarm-spores, as Stra.sbiinßr sliows. 



16) In the centre of the archoplasm is generally seen a centro- 

 some, which often show^s a dumb-bell form. »Sometimes, however, 

 two centrosomes are found in the archoplasm of the spore-forming 

 cells. Fn many cases, again, there is found in the centre of the 

 archoplasm a number of small oval, rod-shaped or curved bodies, 

 staining exactly like centrosomes, instead of one or two centrosomes. 

 These may repi-esent the group of centrosomes of Heidenhein. 



IT) The origin and the fate of the centrosome are not known. 

 In a few instances it appears to be fbi-med from the nucleus. 



Agkiculti ral Cullegp:. 



End of November, 1893. 



