293 
in the Pollen- Mother -Cells of Larix . 
centric to the nuclear membrane, and about midway between 
that and the cell-wall, in which the fibres are bunched. This 
zone appears frequently in the preparations from this stage 
down to that of the equatorial plate, and is suggestive of the 
kinoplasmic zone figured by Mottier (’97, Figs. 5, 6) in the 
Lily. But every cell containing such a zone, so far as I have 
observed, shows a marked shrinking and distortion, and it 
seems extremely probable that the bunching of the fibres is 
here an effect of the fixation. Fig. 16, PI. XV, shows a cell 
at a much later stage, which, in connexion with considerable 
shrinking and some plasmolysis, shows this outer fibrous zone ; 
the fibres here are so arranged in several places as to form 
‘ cyto-asters,’ suggesting those seen by Mottier (’97, Fig. 38) 
in Podophyllum , as well as the asters found by Morgan (’96) 
to be produced in the unfertilized or fertilized eggs of sea- 
urchins and ascidians by treatment with salt solutions of 
a certain strength, and similar asters found by Mead (’98 £) 
in the cytoplasm of unfertilized eggs of Chaetopterus when 
placed in sea- water. In the two latter cases, the cyto-asters 
seem to occur as a result of the action of a solution in which 
the eggs are immersed, the effect being similar, perhaps, to 
that of a poor fixing-fluid. 
During and after the formation of the extra-nuclear felt, 
there is often a concentration of the granular orange-staining 
element of the cytoplasm about the nucleus, giving again 
a vacuolated (not a spongy) appearance to the peripheral 
cytoplasm. The linin gradually becomes more regularly 
fibrous, but the fibres are still ragged and granular. The 
nuclear membrane is still intact, staining deep blue like the 
fibres. The cell shown in Fig. 9 is considerably shrunken in 
fixation ; plasmolysis has pulled the nuclear membrane away 
from the cytoplasm on one side and into the nuclear cavity, 
where it can be followed, by focusing, through the thickness 
of the section. There can be no doubt in a case like this 
that the nuclear membrane is something more than a film 
due to surface tension between the nuclear sap and the 
cytoplasm. It is a distinct cell-organ, which retains its 
