166 CANNON: STUDIES IN PLANT Hysrips 
Prior to the breaking down of the nuclear wall the nucleolus 
(plasmosome) presents indications of its disintegration. Its capacity 
for absorbing the stains is lessened, it becomes vacuolated, and at 
length disappears. The degeneration of the nucleolus takes place 
part passu with the formation of that portion of the nuclear retic- 
ulum which is of karyoplasmic origin, and it may, in fact, contribute 
to its building up, just as occurs according to Strasburger in Facus.* 
The net-work which arises from the linin of the nucleus, from 
the cytoplasm immediately surrounding it, from the disintegrated 
wall, and finally, perhaps, from the nucleolus also, becomes modi- 
fied so that a confused mass of fibers are formed which make the 
felted condition characteristic of the earlier stages in the organiza- 
tion of the multipolar achromatic figure in the higher plants. The 
fibrillae which come from the reticulum become gathered into 
groups with the effect that from the felted condition a multipolar 
one ensues, and from this at length the bipolar figure is formed. 
Several intermediate stages were observed in the transformation 
just spoken of, such as the one figured (/. 8). The cytoplasmic 
cones, which are so prominent a feature in the early stages of 
such an achromatic figure as in Aguzsetum + are wholly wanting 
in the cotton hybrid. The presence of the perinuclear zone of 
cytoplasm, as has been pointed out in Lavatera,t appears to in- 
hibit the formation of the Eguisetwm type of multipolar figure. 
When the achromatic figure is completely differentiated, the 
poles extend nearly or quite to the periphery of the cell, and the 
relation between the achromatic figure and the ectoplasm is the 
same as described by Lloyd § as occurring in Asperu/a. In the 
cotton the relation is a variable one, and appears to depend on 
the size of the cell, as for instance, in the spindles of the second 
division the poles do not reach to the periphery but terminate in 
the outer portion of the cytoplasm. The achromatic figure of the 
cotton hybrid, as in pure races, is made up of three sorts of fibers, 
namely, of the continous fibers, or central cylinder, the contractile 
* Strasburger, Kerntheilung und Befruchtung ‘bei Fucus. Jahrb. Wiss. Bot. 30: 
351- 1897. 
+ Osterhout, Ueber Entstehung der karyokinetischen Spindel bei Zguisetum, Jahrb. 
Wiss. Bot. 30: 159. 1897. 
t Byxbee, 7. ¢. 
§ Lloyd, 7. ¢. 70. 
a Cd 
