340 
Mot tier. — The Effect of 
determined by that of the nuclei, while the proportional 
distribution of cytoplasm plays a secondary and minor part as 
a factor in regulating the division or size of the resulting 
daughter-cells. 
The results of centrifugal action upon older cells of the 
stamen-hairs, i. e., those no longer capable of dividing, and 
whose role is purely vegetative in character, proved to be 
interesting, though of much less theoretical importance. 
A relatively longer time was necessary to effect the desired 
displacement than in those still in the embryonic condition. 
The following remarks apply more particularly to cells in 
which the cell-sap had become only slightly or not at all 
coloured. In mature cells the coloured cell-sap and the 
nature of the cell-wall interfered with a distinct view of the 
living contents. 
In cells where a displacement of a larger part of the 
contents was effected, the nucleus, much cytoplasm, and all 
the larger inclusions, were massed in the lower end of the cell, 
the vacuoles occupying the remaining and larger part of the 
cell-cavity. The cytoplasmic strands which penetrate the 
cavity of the cell, or at least some of them, remained in 
position. As soon as observation was possible, an active 
streaming towards the lower end of the cell was seen in the 
strands, showing that the displaced cytoplasm had begun to 
redistribute itself rapidly. The larger inclusions also began 
to move, and in a short time they were normally distributed 
in the cytoplasm. The nucleus is often slow to move from 
its centrifugal position. Sometimes it may regain a position 
midway between the ends of the cell, shifting the same from 
time to time as under ordinary circumstances ; then again it 
may remain almost stationary in the displaced position. 
Other Trichomes. 
Observations upon various other trichomes, although furnish- 
ing data of much less interest than those of Tradescantia , 
may not nevertheless be wholly without significance. Trichomes 
