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1899] SPORE-MOTHER-CELL OF ANTHOCEROS 103 
suggest transverse fission, but the writer is not willing to accept 
this evidence, as such an arrangement would naturally appear 
when the daughter chromosomes pass away from the nuclear 
plate to the poles of the spindle. 
We have now finished our account of nuclear activities in 
the spore-mother-cell, but there remains for consideration the 
description of the manner in which the cell contents are divided 
to form the spores. After the two mitoses each of the four 
nuclei lies in a region of dense protoplasm at the side of a chlo- 
roplast towards the interior of the cell (fig. 25). The bulk of 
the protoplasm is therefore collected into four masses somewhat 
apart from one another but connected by very numerous delicate 
filaments. The cross filaments are very conspicuous but irregu- 
lar in their arrangement, frequently anastomosing. As shown in 
hig. 25 they are not confined to the vicinity of the nuclei but con- 
nect all portions of the separated regions of protoplasm. They 
do not resemble spindle fibers, being much thicker, but have 
instead the appearance of strands of cytoplasm. Following 
the condition shown in jig. 25 one may find stages similar to 
fg. 26. It is plain that the protoplasmic strands have spread 
sideways and fused with one another so that there is now present 
a film of protoplasm between tetrahedral regions of the spore- 
Mother-cell. This film marks exactly the position that is 
finally to be occupied by cell walls when the spores are fully 
organized. 
spe Petiliarity of the process just described lies chiefly in 
is the ms to be its entire independence of spindle fibers. It 
iiecatie accepted view that the walls crossing spore- 
that GH ee pollen-mother-cells are derived from cell plates 
The writ ee the fusion of spindle fibers after anaphase. 
tion oie. thinks that no investigator has described a condi- 
the Be. to Anthoceros. The present studies indicate a 
€s of the two successive mitoses completely disap- 
pear, ets 
the w This 1S certainly a very difficult point to determine, but 
r ; t 
c iter feels confident that the anastomosing strands which 
Onnec ‘ 
t the four Masses of protoplasm in the spore-mother-cell, 
