550 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
the nucleoles lose their structure, their stainable property diminishes, 
they become smaller and break up, their separate portions having no 
power of absorbing stains. The substance of the nucleoles is therefore 
probably used up in the formation of the chromosomes ; they must hence 
be regarded as bodies for the concentration of the nutrient material in 
the nucleus, i.e. of plastin, chromatin, and similar substances. This 
theory explains the peculiar and variable capacity of the nucleoles to 
absorb stains. It also favours the possibility of an absorption of the 
chromatin from the framework of the nucleus. Chromatolysis is there- 
fore not always a pathological phenomenon. 
Reduction-Division of the Vegetable Nucleus.* — Herr W. Belajeff 
maintains that the negative results hitherto obtained in attempting to 
establish a reduction-division in the vegetative nucleus, similar to that 
which obtains in the animal nucleus, depend on inaccurate observation. 
From the U, V, and X forms of the chromosomes in the condition of 
daughter-aster, he finds, in addition to the heterotypic and vegetative, a 
third mode of division in the nucleus (pollen-mother-cells of Fritillaria 
and Lilium ), corresponding completely to the reduction-division in 
animal organisms ; in this mode of division the form of the chromosomes 
is that of a J. 
Kinoplasm and Nucleole in the Division of Pollen-mother-cells, t— 
Mr. W. C. Stevens has studied the behaviour of the kinoplasm and the 
nucleole in the division of the pollen-mother-cells of Asclepias Gornuti. 
At the time when this division takes place, the relatively large nucleoles 
entirely disappear, and the chromatin breaks up into twelve small chro- 
mosomes. The bulk of the nucleolar substance of the pollen-mother-cell 
appears to remain in a state of solution after the daughter-nuclei have 
gone into the resting state, and is used, at least in part, in the formation 
of the cell-plate. The daughter-nuclei enter into the resting state and 
lose all connection with the spindle at an early stage in the formation 
of the cell-plate, so that the growth of the plate proceeds without any 
kinoplasmic connection of the nucleus with the region of growth. This 
is the reverse of what occurs in the spore-formation of Peziza and 
Erysiphe, and shows that kinoplasmic connection with the nucleus is not 
always necessary to the formation of the cell-plate; and that if the 
daughter-nuclei exert an influence on the formation of the plate, it is 
through the medium of the cytoplasm. 
Blepharoplasts in Spermatogenous Cells.}: — After a review of the 
observations on these bodies by the author himself and by others, Herr 
W. Belajeff gives further details of their formation and structure in the 
case of a fern, Gymnogramme sulphur ea. In those cells in which the 
spermatogenous cells are produced by division, he observed two stainable 
bodies at two opposite points, the poles of the future nuclear spindle. 
After the division of these cells, each of these bodies takes up a position 
corresponding to that of the centrosomes. In opposition to the state- 
ments of Guignard, he finds only one of these bodies in the mother-cells 
* Ber. Deutsch. Bot. Gesell., xvi. (1898) pp. 27-34 (11 figs.). 
t Kansas Univ. Quarterly, vii. (1898) pp. 77-85 (1 pi.). 
x Ber. Deutsch. Bot. Gesell., xvi. (1898) pp. 140-4 (l pi.). Cf. this Journal ante 
p. 31G. 
