316 PHYLUM XIV. ANTHOPHYTA 
the Mints: while still another (the Cup Flowers) begins 
with the Strawberries and culminates in the Sunflowers 
and Dandelions. It will be noted furthermore that the 
Axis Flowers and Cup Flowers agree in regard to their 
cotyledons, arrangement of leaves, vascular bundles of 
stems and leaves, and perianth whorls, causing us to 
consider them as two subdivisions of a common class,— 
Dicotyledons,— coordinate with the Monocotyledons. 
579. Taking a longer look backward it may be seen 
that in the Anthophyta we have the culmination of the 
evolutionary tendencies manifested in the main line of 
plant progress over which we have travelled:—from 
Myxophyceae to Chlorophyceae, thence to the lower 
Bryophyta, and from these to the Old-fashioned Ferns 
(Pteridophyta) and from these again to the Seed Ferns 
and Flowering Plant Ancestors (in Cycadophyta), from 
which the step is relatively short to the simpler Flowering 
Plants. It follows that but five of the preceding phyla 
have contributed to the development of the Flowering 
Plants, and that the eight remaining phyla are side 
branches whose developmental accretions added nothing 
that continued to the Flowering Plants. These five 
contributing phyla contain somewhat less than one-fourth 
of the non-flowering plants, and yet it may be doubted 
whether even more than one-fifth of these again con- 
tributed in any way to the structure of the Flowering 
Plants. So we may say that of the approximately 
100,000 plants in the thirteen phyla preceding Antho- 
phyta, probably no more than 5,000 represent structures 
in any sense ancestral. 
580. It will be instructive to enumerate the greater 
steps in this progressive development from the Myxo- 
phyceae to Anthophyta, as follows: 
