SEEDLINGS OF BLOODROOT. 203 
from the embryonic organ, the hypocotyl. In the case of the 
Bloodroot the hypocotyl soon twists around horizontally and 
becomes an elongated creeping structure, the rhizome. As 
left behind and these account for the branching of the older 
rhizomes. The twisting around of the hypocotyl may be no- 
ticeable within the first week of growth. 
he primary root, or the continuation of the underground 
hypocotyl does not seem to increase in thickness at all. As 
the hypocotyl assumes its horizontal position, the primary 
root and its branches become soon aborted and wither away. 
This twisting and also the gradual disappearance of the first 
root is strikingly evident in the series of plants in the accom- 
panying illustrations. Secondary adventitious roots soon de- 
velop from the lower side of the horizontal hypocotyl now 
become the new rhizome. All the roots of Bloodroot after the 
second year are undoubtedly adventitious. Lubbock reports 
such adventitious roots on the seedlings of Begonia villosa, 
Lindl at an early'stage of growth. 
Examination of plants older than two years has not been 
systematically made, so that there is no direct evidence as to 
the manner in which the older rhizomes branch. It is not even 
known to us whether the buds may not be adventitious, though 
* this is not likely. In any case, the lengthening out of the rhi- 
zomes is a very slow process under ordinary circumstances an 
extended and continued systematic study of older plants is 
necessary. The size and number of the lobes of the leaf seem 
to have some connection with the age of the plants and this 
fact too has not been investigated. 
Conclusions: 
1. The cotyledons and hypocotyl of our form of Bloodroot, 
Sanguinaria mesochora, Greene, are hypogeal and chlor- 
ophylless. 
The rhizome or rootstock of the plant is developed from 
the horizontally twisting hypocotyl, which increases in 
thickness, at first by enlargement in the cortical area, 
and later in the center or pith of the single radial 
bundle. 
. The primary root soon dies, at least before the second 
year, and all the roots of older plants are adventitious. 
Department of Botany, 
University of Notre Dame, 
M 
e 
$ Ibidem. Vol. II, p. 2. 
