420 BOTANICAL GAZETTE [JUNE 
one or two large and deeply staining nucleoli. After 24 hours under 
similar conditions there was little change in the appearance of the 
cells. Plasmolysis in occasional cells and the collapsed walls of the 
outer cell layer indicated that disorganization had begun. 
Next 5/94 normal phenol was allowed to act for 20 minutes on 
root tips, which were then transferred to distilled water for four hours. 
There were no mitoses. In certain cells of the inner periblem and 
in some plerome cells elongating to form procambium, large vacuoles 
occurred, while many enlarged nuclei had partially collapsed. The 
general condition of the cells resembled very closely that obtaining 
after the exposure for four hours to the 10/94 normal solution. After 
21 hours the root tips had made no further growth and were evidently 
dead. Disorganization of the cell structures, however, had not pro- 
gressed so far as in the case of the material with 10/94 normal for the 
same time. Here again the nuclear area was enlarged, though very 
regular in form, and had a lighter hue than the surrounding cytoplasm. 
In the radicles treated for 20 minutes in the other dilutions employed, 
continuous growth occurred and development was apparently normal. 
After 20 minutes’ treatment with n/g4 and 1/188 phenol, respectively, 
and then with distilled water for 45 hours, the root tips were fresh 
and crisp and had elongated at approximately the same rate as the 
distilled water controls. Mitoses were frequent, and the more 
active regions of the cytoplasm, particularly the achromatic figure, 
showed no injury as a result of the action of the phenol. 
Phenol in common with most antiseptics is a marked protoplasmic 
poison. Certain results of its action were especially apparent in 
the cells of the root tips treated continuously with this reagent. The 
achromatic figure of the division nucleus in early anaphase was seri- 
ously injured and mitosis inhibited. The nuclear plate stage was 
apparently unusually sensitive to the action of the phenol, since the 
spindle fibers as a rule failed to function normally in drawing apart 
the daughter chromosomes. As previously noted, the development 
of small vacuoles in the cytoplasm appears to be a characteristic 
effect produced by the phenol. There was no amitotic division and 
no tendency toward the production of binucleate cells was observed. 
In the material treated for 20 minutes with the stronger solutions 
and then with distilled water, the most striking modification was the 
