335 
Anatomy of Ter ato logical Seedlings. III. 
(3) Helianthus annum syncotyleus, but the two do not seem exactly homo- 
logous, since the latter appear to be primarily hypocotyledonary in character 
and, although they occasionally contribute a root pole, they only exception- 
ally constitute a part of the laminar vascular supply, whilst in Impatiens the 
additional vascular complexity of the hypocotyl is the result of the modifi- 
cation and increase in importance of certain of the chief laminar strands. 
