35 2 
Mot tier . — The Effect of 
mould, and the pressure due to the increased weight is so 
evenly distributed that not even the cells of the cap itself 
sustain the least injury, except it be the outermost layer. 
The tubes and funnels are now packed into the cylinders 
previously mentioned, when all is ready for operation. 
In order to observe the condition of the nucleus and the 
other cell-constituents just at the close of centrifugal action, 
tips of the roots were put at once into the fixing fluid 
(chromic-osmic-acetic acid). In order to observe the beha- 
viour of cells at certain intervals subsequent to the action of 
centrifugal force, specimens of Zea remaining in the tubes 
were replaced in the sawdust or kept in a moist chamber. 
Of course, all tips cut from the plant previously to centri- 
fugal action were fixed immediately on their removal from 
the centrifuge. The pieces of tissue were imbedded and 
sectioned. The sections were stained on the slide with 
safranin, gentian-violet, and orange G. By the method of 
preparing the tissue just outlined, the exact condition of all 
the protoplasmic constituents of the cell at the time of fixing 
is revealed in successful preparations with striking clearness. 
As regards the cell-contents as a whole, we find here results 
similar to those already described ; but, concerning the 
nucleus alone, phenomena are met with which merit special 
attention. 
In certain cells of Zea, Vicia , and Phaseolus , not only do 
we find the contents of the nucleus displaced in its cavity as 
in the case of the cell, but the nucleolus may often be forced 
out through the nuclear membrane into the cytoplasm, when 
nucleus and nucleolus will be found lying some distance apart 
with all connexion between them severed. This shows quite 
clearly that the nucleolus is relatively much heavier than the 
other constituents of the nucleus. 
Only one instance is known to the writer of any recorded 
observation upon this phase of the subject, namely that of 
Herrick (’95), referred to by Davenport 1 (’97) in his Experi- 
mental Morphology. As stated by Davenport, Herrick found 
1 Herrick’s paper was not accessible to me. 
