211 



Fig. 127. 



Conillina ofliciimlis. Fused cells from a verlicul 

 section ol' a young joiul under a young sporangial 

 conceptacle. 730 : 1. 



Heilkunde zii Bonn 1880) thai the nuclei, in two fu.sing cell.s of Jaiiia riibens did 

 not fuse together. I came to a diflerenl result on investigating this point in several 

 other species, especially Corallina officinalis. In a tetraspore-hearing 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 

 and derived from fusion of the two nuclei 

 (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, 1 have observed in Lithothainnion glaciale var. 

 Granii (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- 

 cleate syncytia are found even in older tissue. It is not un- 

 likely that the nuclei may themselves co-operate in the pro- 

 cess of fusion, the nuclei of the two cells placing themselves 

 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 



Fig, 128. 

 lAlholhamnion glaciale var. 

 Granii. Syncytia produced 

 by fusion of from two to four 

 cells, all showing only one 

 nucleus; at right a cell con- 

 taining starch grains. (SO:!. 



