STEVENS: KINOPLASM AND NUCLEOLUS. 79 
formation of the spindle is still seen to be attached to it as nucleolar 
substance, and this occurs not only in the connecting fibres but 
also in the kinoplasmic radiations throughout the cytoplasm. By 
the use of the safranin-gentiana violett-orange staining method the 
violet color of the kinoplasm begins to decrease at the time when 
the nucleolar substance reappears in the daughter nuclei. In the 
formation of the plasma membrane about ascospores the nucleus 
remains in kinoplasmic connection with the membrane until the 
latter is fully developed, and this Strasburger considers to be evi- 
dence that there is an intimate relation between the substance of 
the nucleus and the kinoplasmic membrane, the nucleolus being 
the structure of the nucleus which is particularly concerned. 
Strasburger gives his conclusion from the above evidence in the 
following words: ‘‘Zwischen Kern und Kinoplasma besteht also, 
allem Anscheine nach, ein sehr nahes VerhAltniss, und ich griinde 
auf dasselbe die Ansicht dass die Nucleolarsubstanz einen Reserv- 
estoff reprisentirt, aus dem das Kinoplasma nach Bedarf schépft 
und durch dessen Aufnahme seine Thatigkeit erh6ht wird.’’! 
The fact that the kinoplasm is seen to arise during nuclear divis- 
ion in all parts of the cytoplasm? is good evidence that it is distrib- 
uted equally throughout the cytoplasm when nuclear division is 
not taking place, although kinoplasm and trophoplasm are indis- 
tinguishable during the resting stage of the nucleus, excepting 
when successive nuclear divisions rapidly follow each other. # 
Trophoplasm and kinoplasm probably remain distinct from each 
other, although it is not impossible that one may increase at the 
cost of the other. Strasburger has summed up the evidence af- 
forded by plants for and against this view.* He calls attention to 
the fact that in dividing cells large quantities of kinoplasm appear 
which can no longer be made out in the resting cell, while the very 
opposite frequently occurs with the trophoplasm; a fact which 
seems to point to the mutual interchangeability of these two struct- 
ures. However he calls attention to considerations which point 
the other way. The uniformity with which the kinoplasm in cell 
division is apportioned between the daughter cells; the formation 
by the kinoplasm of the plasma membrane which demarks the 
spores of Erysiphe and Peziza from the ascoplasm, without any 
apparent participation of the trophoplasm; the apparent exclusion 
1 Strasburger, Cytologische Studien, pp. 224-225. 
2 Osterhout, Ueber Entstehung der karyokinetischen Spindel bei Equisetum. (Cy- 
tologische Studien. pp. 6-7.) And Mottier, Beitraege zur Kentniss der Kerntheilung in 
den Pollenmutterzellen einiger Dikotylen und Monokotylen. (1. c. pp. 22-30.) 
3 Strasburger. Ueber Cytoplasmastructu:en, Kern und Zelltheilung. (1. ¢. p. 222.) 
41. ¢c. pp. 224-229. 
