ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
169 
separate centrosomes, become more prominent. This is the daughter - 
star stage. 
IY. Telophase. (7) The chromosomes, having arranged themselves 
around the poles, now begin to contract, becoming wavy in outline, and 
the free ends curve inward. The threads of the central spindle begin 
to thicken, preparatory to the formation of the cell-plate. In the centre 
of each thickened thread a granule appears, these being formed first in 
the central strands ; and as the spindle bulges outward, the cell-plate 
gradually enlarges until it reaches the surrounding cell-wall. In the 
meantime the nucleoles begin to appear in the daughter-nuclei. This 
may be called the loose daughter-skein stage, and may be considered to 
end when the cell-plate is complete. (8) After the daughter-cells are 
completely separated by the new cell- wall, the threads of the central 
spindle disappear, and the daughter-nuclei appear with complete nuclear 
membranes. The chromosomes begin to be transformed again into the 
chromatin network ; the radiations disappear from around the centro- 
spheres, which have now usually divided completely into two separate 
bodies ; and the two daughter-nuclei in the meantime expand, and take 
on a more spherical form, until they enter again into the resting stage. 
This may be known as the close daughter-skein stage. 
Cell-Division in Pinus.* — Mr. E. L. Fulmer has undertaken an 
examination of the process of cell-division in seedlings of Pinus Laricio ,. 
for the purpose of determining whether the achromatic spindle originates 
as a bipolar or a multipolar structure. The evidence obtained supports 
the former view. In the resting stage of the nucleus no centrospheres 
were observed. At about the time that the spindle becomes pointed, the 
spirem breaks up into a definite number of chromosomes, and the nuclear 
membrane disappears. At this time the nucleoles are no longer visible, 
having disappeared during the early prophase stage of division. The 
centrosomes in Pinus appear as small but definite and readily stained 
bodies lying at the poles. 
Action of Gases on the Currents of Protoplasm* and on Cell-divi- 
sion.f — Herr P. Samassa states that, in the staminal hairs of Trades- 
cantia, pure oxygen does not accelerate the circulation of the protoplasm ; 
while both hydrogen and carbon dioxide cause complete suspension. 
Contrary to the assertion of Demoor, he finds that, when oxygen is 
not present, no division of the nucleus takes place. No cyclosis of 
the protoplasm is exhibited in the terminal cells of the hairs while, 
dividing. 
(2) Other Cell-Contents (including- Secretions). 
Carbohydrate Reserve-materials of Bulbs and Tubers. f — M. Leclerc 
du Sablon has studied the composition and the mode of formation and 
digestion of the reserve food-materials in a large number of bulbs, 
tubers, rhizomes, and corms. They always consist essentially of carbo- 
hydrates, such as starch, inulin, dextrins, and sugars, distinct or asso- 
ciated with one another. In the tubers of the potato, the rhizomes of 
* Bot. Gazette, xxvi. (1898) pp. 239-46 (2 pis.). 
t Yerhandl. Natur-liist. Ver. Heidelberg, vi. (1898) Heft 1. See Bot. Ztg.. lvi. 
(1898) 2 te Abth., p. 344. 
X Rev. Gen. de Bot. (Bonnier), x. (1898) pp. 353-69, 385-403, 447-82 (15 figs.). 
Comptes Rendus, cxxvii. (1898) p. 968. 
1899 
N 
