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1899 | SPORE-MOTHER-CELL OF ANTHOCEROS gI 
As is well known, the sporogonium of Anthoceros grows from 
a region of embryonic or meristematic tissue in the slightly con- 
stricted portion of the structure just above the foot. From this 
region there rises a central columella around which are arranged 
in the form of a hollow cylinder the cells destined to develop 
into spores and sterile cells (elaters). Recently published 
accounts of the structure and development of the sporogonium 
by Campbell (95, pp. 130-131) describe this hollow cylinder as 
two layers of cells thick and composed of groups of spore-mother- 
cells separated by clusters of sterile cells that later become the 
elaters. The writer’s preparations indicate far less regularity of 
structure than this description would imply. In many cases the 
Spore-mother-cells formed a single layer around the columella 
and the amount of sterile tissue was very insignificant. Only 
eccasionally was the layer of cells distinctly double and then 
Na irregularly so. There appears, therefore, to be considerable 
Variation in the complexity of the sporogenous tissue in Antho- 
feros, and the simplest conditions approach very closely the 
“rangement of cells reported by Campbell (98) for Dendro- 
ceros, 
The cubical cells of the archesporium frequently contain 
nuclear figures, but the spindles are very small and unsatisfac- 
tory for study. Such a spindle is shown in fig. 7, with the 
oo separating into two groups and about to Pe to 
we oe cytoplasm is granular and contains minute 
“Ss. The writer was not able to find a trace of the chloro- 
plast _ these cells, but looks forward to a further study of this 
Point in living material and with special methods of staining. 
8 ae cells become very quickly differentiated 
Mee in size. Their nuclei are not at first to be 
hee ¢d from those in the cells of the archesporium, for 
at are small and contain the one prominent nucleolus and an ill- 
. en ete linin threads. The most asta Seth change 
Plast. This 2 e appearance in fixed material of the chloro- 
bhincs ia Tucture is at first a slightly denser mass of pig: 
€ other contents of the cell, but so small that it 
