78 BOTANICAL GAZETTE [AUGUST 
shortly before the cell plate is formed ‘‘extra-nuclear nucleoli” 
appear in large numbers in the equatorial region of the spindle, 
and that by the time the cell plate is complete these have dis- 
appeared, he argues that the nucleolus takes part in building the 
cell plate. : 
In the pollen mother cells of Liiium Martagon, Farmer * found 
that the protoplasm of the connecting spindle on each side of 
the newly formed cell plate is relatively transparent. | 
The series of contributions which‘appeared from the Bont 
laboratory in 1897 presented several important facts in regard 
to the formation of the cell plate. Mottier*s found in the pol 
len mother cells of the lily that the cell plate is split into 
plasma membranes before the cell wall is laid down. In cells 
plasmolyzed in fixing, a complete plasma membrane was see 
around each daughter cell, while no cellulose wall could be 
observed (of. cit., p. 192). In the pollen mother cells of Heme 
rocallis fulva, Juel** found that after the first nuclear division the 
cell plate did not reach the mother wall but remained free in the 
cytoplasm until the second nuclear division occurred and new 
cell plates were formed at right angles to it. Then some of the 
fibers radiating from the daughter nuclei become attached to es 
old plate, and all the cell plates now continue their respectité 
growths toward the mother cell wall. Debski*7 studied the di 
sion of the segment cells of Chara and observed that the long 
axis of the spindle is parallel to the shorter axis of the cell # 
further that the cel] plate is not formed across the equator : 
the spindle but nearer one nucleus. In the formation of 
ascospores in the asci of Erysiphe and Peziza, Harper*® fou 
4 Kerntheilung in Lilium Antheren, besonders in Bezug auf die Centrosome 
frage. Flora 83 : 167. 1895. 
*S Beitrage zur Kenntniss der per Sia Se in ag Pollenmutterzellen ein 
Dikotylen u. — Jahrb. f. wiss. Bot. 1897. 5 
6 Die Kern heilungen in den Pulls saci. yon Hemera files 
bei denselben PAN Unregelmassigkeiten. Jahrb. f. wiss. Bot. 30: 2°: 
HE pte liber Kerntheilung bie Chara fragilis. Jahrb. f. wiss. Be 
397. 
30: 227. 
ripe Kehibaig und freie Zellbildung im Ascus. Jahrb. f. wiss- Bot. 30% 
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