zahl 
Heilkunde zu Bonn 1880) that the nuclei, in two fusing cells of Jania rubens did 
not fuse together. I came to a different result on investigating this point in several 
other species, especially Corallina officinalis. In a tetraspore-bearing plant of this 
species I found the fusions followed by a fusion 
of the nuclei. The process was studied in the 
central tissue under a young conceptacle where 
numerous fusing cells were found, partly in 
pairs, partly a greater number fusing together. 
As shown in fig. 127, the two nuclei of a fusing 
pair of cells are frequently found lying near 
each other at the place where the two cells 
have fused together, and there is reason to 
believe that the nuclei have been active in 
the realisation of the cell-fusion. In some 
cases the nuclei were found touching, and 
finally fused cells were found containing 
only one nucleus situated at the same place 
Fig. 127. 
Corallina officinalis. Fused cells from a vertical 
and derived from fusion of the two nuclei section of a young joint under a young sporangial 
conceplacle. 730:1. 
(fig. 127 D). These fusional nuclei seem to be 
able to fuse with other nuclei when fusion takes place between more than two cells. 
In fig. 127 D is shown a syncytium produced by fusion of four cells and containing 
at left two nuclei in mutual contact and near the middle a nucleus which must be 
supposed to have arisen from fusion of the nuclei of the two cells at right. This 
nucleus has approached the middlemost opening, where it would perhaps later on 
have fused with the other fusional nucleus. Syncytia arising from fusion of four 
cells but containing only one nucleus, undoubtedly produced by fusion of the nuclei 
of the cells, I have observed in Lithothamnion glaciale var. 
Granü (fig. 128). Also in Melobesia uninucleated syncytia pro- 
duced by fusion of two cells were observed. It must therefore 
be supposed that fusion of nuclei generally occur in the 
fusing cells. 
That Schmitz has not observed them may be due to the 
fact that the process was not so far advanced in the plant 
investigated by him; it might also be imagined, however, 
that fusion does not take place in all cases, since mullinu- 
Fig. 128. 
Lithothamnion glaciale var. A 2 
Granü. Syncytia produced cleate syncytia are found even in older tissue. It is not un- 
by fusion of from two to four : : 7 or 1 a R 
cells, all showing only one likely that the nuclei may themselves co-operate in the pro- 
nucleus; at right a cell con- cess of fusion, the nuclei of the two cells placing themselves 
taining starch grains. 650: 1. : 0 BMA 
opposite each other in the two cells and bringing about a 
dissolution of the cell wall. The reason of their taking up such a position would 
then be, that a mutual attraction exists between them, in which case it would be 
natural to suppose that such attraction should continue to exist after the fusing of 
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