1914] COULTER & LAND—MONOCOTYLEDONY 511 
one another, and their phloem strands become united (fig. 9). 
Farther down the three cotyledonary strands unite completely, and 
the phloem divides (fig. 10). The single bundle of the first leaf 
turns inward (figs. 9 and 10) and unites with the cotyledonary 
strands (fig. 11). The lateral bundles of the leaf are disregarded. 
embryos of A gapanthus umbella- 
Fic. 1.—M tyled ; and dicot 
tus; X4. 
since they appear late, and in early seedling stages are not con- 
nected with the main strand or with the cotyledonary plate. This 
union of strands, three from the cotyledon and one from the first 
leaf, forms a siphonostele (fig. 11), which is the “cotyledonary 
plate.”” The strand from the first leaf continues into the hypocotyl 
and becomes one of the poles of the root, and from the cotyledonary 
strands that enter into the structure of the cotyledonary plate, two 
other strands pass down the hypocotyl to form poles of the root, 
