in Didyota dichotoma. 183 
This point of view does not assume that everything which 
remains blue after careful differential staining with the triple 
stain used is kinoplasm, nor is it claimed that the colour of 
any part of the plasma, resulting from a certain staining 
method, indicates the chemical nature of the part so stained. 
The colour may or may not do so ; decisive proof is still 
wanting. 
In vegetative cells the formation of the cell-plates is like¬ 
wise interesting. The connecting fibres between the daughter 
nuclei disappear as such (Fig. 22), and the plasma-membrane 
seems to be laid down as in the delimination of the tetraspores. 
It was not possible to follow the process in as great detail 
as in the tetrasporangium, but in the case observed the cell- 
plate began at the periphery of the cell and proceeded toward 
the centre (Fig. 22). The process is not a cleavage, as 
described by Harper for Zygomycetes, nor is it similar to 
the Spirogyra or Cladophora type, but is the same as described 
above. Fig. 22 is not magnified sufficiently to show the 
finer details clearly. 
We have now to consider more fully the nature of the 
cell-plate, what its finer structure is, and whether it is formed 
double or as a single membrane, which afterwards splits to 
furnish the daughter cells with their respective portions of 
plasma-membrane. 
In the pollen mother-cells of Lilium ( 1 . c., ’ 97 ) I showed 
that the cell-plate was formed through the direct agency of 
the connecting fibres, but the precise manner in which its 
substance was deposited was left an open question. ‘ Es 
unterliegt ( 1 . c., p. 192), wie es mir scheint, keinem Zweifel, 
dass die Verbindungsfaden in directer Beziehung zu der 
Zellplattenbildung stehen, doch in welcher Weise, bleibe 
dahingestellt.’ There the cell-plate is, at first, so far as can 
be seen, a single homogeneous disk separating the daughter 
protoplasts. Later, it appears double, when the contiguous 
surfaces of the two cells are provided each with a plasma- 
membrane ( Hantschicht ), between which a cell-wall is formed. 
Whether the cell-plate in either Lilium or Didyota is laid 
