136 BOTANICAL GAZETTE [AUGUST 
soil and subjected to the action of plasmolyzing agents. A few of 
the experiments undertaken will be given in detail. 
A young seedling, with a slender primary root 2°™ long, showed 
distinct plasmolysis of the epidermal cells near the root-tip within 
five minutes after being placed in 3 per cent. solution of potassic 
nitrate, and the same phenomenon was soon after obtained as far 
back as 1.6°™ from the end of the root. Some of the root-hairs also 
showed plasmolysis, but not so strongly as the epidermal cells. In 
the latter it was particularly distinct. 
At the same time a number of good specimens growing in the 
Geneva tester were treated on separate slides with 2, 3, 4, and 5 per 
cent. solutions of KNO, at a temperature of 27°C. With the 2 per 
cent. solution plasmolysis was not observed; with 3 per cent. it was 
seen doubtfully or incompletely in a few of the epidermal cells; with 
4 per cent. plasmolysis in many epidermal cells was strongly marked; 
and with 5 per cent. not only was plasmolysis promptly and strongly 
induced in the epidermal cells but also in some of the root-hairs. It 
is seen from this experiment, and from others not reported, that the 
root-hairs plasmolyze less readily than the neighboring epidermal 
cells. In the present case, while the application of 5 per cent. solu- 
tion of KNO, was promptly followed by plasmolysis of some of the 
root-hairs, others failed altogether to exhibit the phenomenon. 
Similar results were obtained from a lot of seedlings raised in soil 
in flower pots. They were strong and healthy, and at the end of five 
weeks’ growth, when they were taken up for experimentation, some of 
them had one or two leaves well developed Employing the secon 
dary roots of one of the best developed individuals it was found that 
plasmolysis did not occur in 3 per cent. solution of potassic nitrate; 
that it took place promptly and distinctly in 5 per cent., both in epr 
dermal cells and root-hairs; and that in 4 per cent. different specl- 
mens exhibited a marked difference of behavior. Of five specimens 
placed in 4 per cent. solution two showed plasmolysis ‘satisfactorily, 
both of the epidermal cells and root-hairs, while two failed to do 80, 
and one showed plasmolysis well in the epidermal cells but not in the 
root-hairs. 
In these, as generally in roots subsequently examined, it We 
found that the older root-hairs, farther back from the tip of the root 
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