ix Plant Cytology. IgI 
chromatin alike build up each chromosome, since both share 
equally in the division process, since both exist in spore and 
sex cells, and since both, according to my own studies, as well 
as those of Wisselingh and others, make up the stainable 
nucleolar substance, may we not regard the general cytoplasm 
and nucleoplasm as the vegetative substance of the cell, the 
chromatin granules as che highly specialized hereditary substance, 
and the linin as an intermediate substance which transmits 
hereditary peculiarities in slow degree from the cytoplasm to 
the chromatin, and is itself the bearer in part, of hereditary 
peculiarities. To this we can conveniently return after con- 
sideration of the nucleolus. 
The literature bearing on the zucleolus has been so recently 
collected, and expanded from the zoological standpoint in 
Montgomery’s valuable paper, that it may seem necessary 
only to compare the views there presented. But so rapid 
have been the advances on the botanical side during the past 
two years that the views of Wager, Debski, Farmer and 
Williams, Sargant, Wisselingh and others, might importantly 
modify our conceptions. 
The resting nucleolus, when fixed and stained, shows a 
density of stainability that is only and exactly paralleled by 
the chromatin granules, and to a less extent by the linin. 
Moreover, the total amount of the latter substances in the 
perinucleolar area of most embryonic cells in the resting state, 
would not account for the bulk of the chromosome granules. 
On the other hand the vegetative cells of most coniferous 
plants, and in such growing apices as Passiflora, Nerium, 
Bougainvillea, the nucleolus, though distinct, is relatively 
small, while the perinucleolar area is rich in refractive stain- 
able substance in the form of loops. As is now gen- 
erally acknowledged, the resting and dividing nucleolus of 
species of Spirogyra bears nearly all the chromatin as well 
as linin material, and in the dividing stage becomes halved, 
