294 WATTERSON: EFFECT OF CHEMICAL IRRITATION 
increase in the intensity of respiration, both normal and intra- 
molecular, of etiolated leaves and shoots under the influence of 
ether, alcohol and various alkaloids. Pfeffer states * that accord- 
ing to Elfving and Lauren adult parts of higher plants, where 
stimulation is unaccompanied by growth, react in the same manner 
to a short treatment with ether and chloroform ; he notes how- 
ever that Detmer and also Bonnier and Mangin found no such 
reaction, 
Summarizing then, the results quoted, we find that small 
quantities of certain poisonous substances act as stimulants, increas- 
ing the growth of certain plants; they also increase respiration, 
but what relation the latter increase bears to the former is not 
determined. Since, however, in the case of fungi, it has been 
found that stimulation raises the economic coefficient of the sugar, 
2, ¢., allows the plant to make use of the sugar to form a greater 
amount of dry substance in a given time, the question of the 
amount of CO, which is produced at the same time becomes one 
of interest. 
This problem was suggested to me by Dr. H. M. Richards, 
to whom I wish to express my gratitude for his interest and valu- 
able assistanee. The work was done in the botanical laboratory 
of Barnard College during the winters of 1901-1902 and 1902- 
1903. 
Two kinds of apparatus have been employed in carrying on this 
work, one that of Godlewski described by Kunstmann f the other 
a modification of the Pfeffer-Pettenkofer apparatus. In all the 
experiments, however, the fungi used were Sterigmatocystis nigra 
and Penicillium glaucum. The formula for the nutrient solution 
was that given by Richards : ¢ 
KH,PO, 005g. 
MgSO, 0.25g- 
NH,NO, 1,00g. 
FeSO,.. trace 
MURAR Hiei ic covet bearcaceek Cee hess Cink 5.00g. 
fat Ioo cm 
Only the purest chemicals and sugar obtainable were used, 
+ Kunstmann, /. ¢. ro. 
f Richards. Jahrb. Wiss. Bot. 30: 667. 1897. 
* Pfeffer, W. Physiology of plants, Ed. 2, 1: 564. 1900. 
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