34 Sargcint . — Theory of the Origin of Monocotyledons 
The transition from stem- to root-structure takes place 
rather suddenly at the base of the hypocotyl (C, Diagram 
VIII). It resembles that of Fritillaria and Lilium. 
A B C 
Trillium grandiflorum . The cotyledon contains a main 
bundle and two lateral ones. The main bundle opens out 
above the first node, and is clearly a double structure. One 
phloem group and two protoxylem rays of the triarch roof 
are derived from it : the rest from the lateral and plumular 
traces. 
There are points in this transition which suggest that 
of Veratmm , but I have not examined any allied species, 
and do not venture to draw a definite conclusion. 
6. Tribes : Dracaeneae, Asparageae, Aloineae. 
The species examined from these tribes are all of woody 
habit, or climbers. The structure of the seedling has been in 
most cases adapted to the conditions of life by changes in its 
vascular structure so profound that they disguise the primitive 
symmetry more or less completely. In nearly all cases the 
plumular traces enter the hypocotyledonary stele, and they 
commonly take the larger share in determining its symmetry. 
Five species representing three genera have been thoroughly 
examined among the Dracaeneae. 
Cordyline australis. The seedl ing resembles that of Muscari 
externally, but is larger. The first leaf shows early. There 
are two bundles in the cotyledon which are quite distinct until 
