62 BOTANICAL GAZETTE [JANUARY 
before such treatment; there is also an increase on the fifth day over 
the fourth. In the case of stems with steamed sections no such 
increase occurs, as is shown by table VI. The steaming causes an 
immediate and continued falling off in the amount of water tran- 
spired. The plants used for the experiment, the results of which 
are tabulated in tables VII and IX, were examined microscopi- 
cally and tested with alkanin, and very little plugging of the 
lumina was found. No such discoloration of the parenchyma 
surrounding the bundles was observed as occurs in steamed stems. 
TABLES VUI AND IX 
SHOWING THE EFFECT ON DAILY TRANSPIRATION BEFORE AND AFTER KILLING 20 CM. 
OF STEM WITH WAX HEATED TO r10 C. 
—_ abana, part enters TaBLE [X—OBSERVATIONS AFTER KILLING 
* ——— 
Date Loss | Average Weath Date Loss | Average) weather 
vege tem- Pcie com ioe tem- | conditions Remarks 
Igro_ | grams |perature Igto grams perature 
May 17} 1.1 | 19° C.| Cloudy || May 22 | 1.9 |19°C.| Clear | Plant — 
condition 
May 18| 2.0 | 24°C.| Clear May 23 | 2.6 | 20° C.| Cloudy ee in 
: condition 
May 19| 2.5 | 24° C.| Clear May 24 | 1.8 | 21° C.| Cloudy | Plant « = good 
condition 
May 20} 2.7 | 25° C.| Clear May 25 | 1.4 | 26°C.| Cloudy | Plant in good 
condition 
May 21 | 2.3 | 29° C.| Slightly || May 26 | 1.6 | 26°C.| Slightly | Leaf tips very 
| cloudy | cloudy ightly yellow 
Average loss in 24 hours=2.12) Average loss in 24 hours=1.86 grams. 
grams. 
ee 
sm 
The leaves also showed very little plasmolysis in the mesophyll 
cells, and the chloroplasts were in good condition. These results 
undoubtedly indicate that hot wax is superior to steam for killing © 
the cells of stems without disarranging the tissues. a 
In view of ScHROEDER’s observations, it will be instructive © — 
examine again the results shown in table VI. After 1o cm. of the 
stem were steamed, a successive diminution in the amount of water 
lost in each 24 hours occurs. The leaves behave exactly as though 
they were wilting from lack of water supply, except that the proces 
is not so rapid, owing probably to a certain amount of water being 
able to rise in the not completely plugged vessels. It is further 
