CHROMOSOMES IN RESTING NUCLEI. 185 
mentation of mitotic nuclear division. These are notably 
nuclei of cells which contain a quantity of other matter in 
addition to the usual cell-plasm—such as the nuclei of 
gland cells, and cells which function as storages of food 
material. 
It would be premature to put forward any theory appli- 
cable to the described cases, which as yet are not numerous, 
but it may be worth while to call attention to the facts. 
Some examples of these nuclei, copied from recently 
published work, are shown in the plate. 
With regard to gland cells, it is noteworthy that secretive 
activity seems to have the effect of altering the quantitative 
relations of chromatin and nucleolar matter. 
Fig. 1 is a nucleus from a leaf of Primula sinensis, 
The leaf is charged with a poisonous fluid, and covered with 
glandular hairs which secrete it. 
Fig. 2.—Nuclei from milk-secreting cells of guinea-pig. 
(Szabo, J., “‘ Die Milchdriise im Ruhezustande, und wahrend 
ihrer Thitigkeit,” Arch. f. Anat. u. Phys. 1896.) In the 
inactive state (a), there is much nucleolar matter, forming 
several nucleoli. As soon as secretion begins (6), only one 
nucleolus is present, but chromatin bodies appear at the 
periphery of the nucleus. 
Fig. 3.—Nucleus from the spinning gland of a caterpillar, 
Pieris rape. (Menes, Dr F., “ Zur Struktur der Kerne in den 
Spinndriisen der Raupen,” Arch. f. Mik. Anat., 1896, Bd. 
48.) The author considers the large bodies to be nucleolar 
matter, and the small granules chromatin. 
Fig. 4. a, 6, c.—Nuclei from the spinning gland of a cater- 
pillar, Pieris brassicw. (Korschelt, E., “ Ueber die Struktur 
der Kerne in den Spinndriisen der Raupen,” Arch. f. Mik. 
Anat.,1896, Bd. 47.) This author considers the large bodies 
to be chromatin, and the granules nucleolar. The figures 
represent nuclei of cells in different stages of secretive 
activity, and show the quantitative changes in the nuclear 
elements. 
Fig. 5.—Nuclei from gland cell of Drosera rotundifolia. 
(Huie, L., “Changes in the Cell-organs of Drosera rotundi- 
folia, produced by feeding with Egg-albumen,” Quart. 
Journ. Mic. Sci., vol. 39, N.S., 1897.) (a) Inactive condition. 
