Multinucleated Condition of the Vegetable Cell. -49 



The multinucleated condition would be thus produced 

 then in cells in a manner somewhat after this fashion : 

 — In cells that are young and dividing rapidly, the 

 nucleus is then in possession of its full vitality, and can 

 iufluence the surrounding protoplasm, causing, finally, the 

 formation of a septum. A little later the nucleus has lost 

 some of its vitality or " power of division/' and, as a result, 

 is unable longer to influence the general cell-protoplasm. 

 It is still able to divide itself, however, and passes through 

 all the stages of indirect division except the formation of a 

 cell-plate. Such a case would be that in the cells of the 

 suspensor of some Leguminosce. Still later, again, we may 

 imagine the nucleus in a well-nourished plant retaining 

 enough vitality to divide directly without going through 

 the phenomena of indirect division. This is, as it were, 

 the " last functional effort" put forth by the nucleus before 

 retiring into a state of rest. Disintegration may, as noticed 

 by Strasburger, occur immediately, or the cell may con- 

 tinue multinucleated for some time. The presence of 

 several endo-uucleoli in each nucleus, or of several nucleoli 

 in each nucleus, I look upon as simply a modification of 

 the same condition. All these conditions may occur 

 together in one cell, or any one or two may occur. The 

 presence of several nucleoli in one nucleus seems to be the 

 commonest condition. 



In plants of low structure, such as Derhesia, the multi- 

 nucleated condition of the cells is not analogous to that in 

 the vegetative cells of phanerogams, as in such a plant the 

 condition is quite normal, and merely occurs in the process 

 of reproduction, In cells, however, such as those of Chara, 

 which are past division, the hypothesis of extra nutrition 

 applies, no doubt, equally. 



According to Strasburger, fragmentation of the nucleus 

 occurs as a final change before its disintegration in some 

 very old cells of Tropceohcm and Nicotiana. This must be 

 looked on as a senile change, nay, almost a pathological 

 condition. It may be caused by an irritant. 



With regard to the comparative frequency of occurrence 

 of this phenomenon among Dicotyledons and Monocotyle- 

 dons, I believe Strasburger's idea that it is most frequent 



TR.WS. BUT. SOC. VOL. XVI. D 



