SUPPLEMENT. 
THE FAMILIES OF FLOWERING PLANTS. 
By Cuaries Lours PoLiarp. 
CHAPTER XII. 
General Characters of the Dicotyledons;. The Orders Verticillatae and 
Piperales. 
We have now completed a somewhat hasty review of the families 
belonging to the class of Monocotyledons. ‘I'he reader must revert to 
our discussion of the differences between this group and the Dicotyledons 
in Chapter III, (pp. 15 and 16) of the Supplement. Dicotyledonous 
plants vastly outnumber those of the other class, and present such 
marked types of structure that it is necessary to group the numerous 
orders of which they are comprised in two subclasses, the Archichla- 
mydeae and the Metachlamydeae. These tremendous names have a 
significance which will be remembered when their etymology is under- 
stood. Both are derived from the Greek language, Archichlamydeae 
meaning plants with a primitive floral envelope, and Metachlamydeae 
those with a waited floral envelope. The co-ordination between these 
terms becomes more evident when we recollect that union of parts in 
floral structure indicates, in our modern understanding, a more highly 
advanced type. Theref re all plants like the morning-glory, the fox- 
glove or any composite, having a corolla composed of a single piece, 
are considered higher in the systematic scale than plants like the 
buttercup, with a corolla of separate petals, or the pigweed, with no 
corolla at all; hence the latter examples belong to the ‘‘primitive’’ type 
of floral structure. It therefore follows that the Archichlamydeae 
embrace, first, all plants having flowers without any corolla (Apetalae), 
* and second, all plants having flowers with a corolla of separate petals 
(Polypetalae). The Metachlamydeae comprise all plants having flowers 
with a corolla united in a single piece. There are, of course, excep- 
