iM 



EX S .VITH OLEANDER. 



The plants were rooted cuttings of llerium 

 oleander . 15 centimeters high and grown in soil con- 

 sisting of 2 parts loam and 1 part sand, by volume. 

 The technique was the same as with Ooleus. Two indivi- 

 dual plants were tested with nitrogen in the usual man- 

 ner, controls being provided as before, I'.o injury was 

 observed for 14 and 12 days, respectively. At the end 

 of these times the leaves nearest to the base of the stem 

 began to turn yellow and fall off. This yellowing ex- 

 tended in a few days to the leaves next above, and thus 

 progressed slowly up the stem, but at a slow rate. The 

 top leaves of both plants were apparently still healthy 

 when the experiments were stopped, after 43 and 25 days 

 respectively. At no time was there any determinable 

 slowing of the water- intake nor was there any perceptible 

 wilting, formal oleander plants, when deprived of water, 

 show a characteristic apiral curling or rolling-up of the 

 leaves which apparently corresponds to wilting in such 

 species as Coleus. This was not observed in the plants 

 treated with nitrogen. After the experiment the root- 

 systems of both oleanders were found to be dead and 

 much decayed, the injury to the roots being much more 

 severe than to the tops. Ho tests were made as to the 

 possibility of recovery on the re-admission of oxygen. 



