70 SELBY: STUDIES IN ETIOLATION 
The determination of the water and dry matter in the stems of 
these specimens gave the following results : 
Dry SUBSTANCE IN STEMS OF Euphorbia corollata 
Normal plant Etiolated plant per cent. 
per cent, I Il Average. 
Water -9O gI.11 89.63 90. 37 
Dry substance....., 13.10 8.89 10.37 9.63 
SE NI i \ 7 
aN SA ac 
NSN 
) S. ye qi 
y 
Eo an DS 
Ficure A. Normal plant of Euphorbia corollata. 
Ficure B. Etiolated plant of Euphorbia corollata. 
A transverse section of the stems showed (plate s, figure 1) 
in the normal a rather feeble development of the strengthening 
tissue and a cambium of several layers of short cells. The woody 
parts of the cylinder were irregularly and feebly developed, bring- 
ing the g f ls into great f i e. Theetiolated stem, 
as before stated, showed (plate 5, figure 2) a tendency to develop 
cortical parenchyma and the woody portion scarcely less devel- 
i a 
