SELBY: STUDIES IN ETIOLATION 71 
oped than in the normal. These differences will be evident in the 
illustrations (plate 5, figures 1 and 2). Referring to the analysis 
it is observed that the increase in the thickness of the etiolated 
stems has not been accompanied by any considerable increase of 
solid matter and that the etiolated plant contains about 3% per 
cent. more water than the normal. These results are in harmony 
with those previously obtained by others. 
= 2 : a it 
Ficure C, Normal plant of Asclepias incarnata. 
Ficure D. Etiolated plant of Asc/epias incarnata. 
Roots of Asclepias incarnata were likewise collected at Woos- 
ter, and plants grown from them in the etiolating chamber and the 
Propagating house of the New York Botanical Garden. The 
etiolated plants of this milkweed started to grow earlier than the 
normal, and produced longer stems (figures C and JD). These 
developed as many as 13 or 14 internodes, with a length varying 
between 5 and 12 cm. The lower axillary buds of the etiolated 
