re than two
carpels. It contains 12 orders in 3 cohorts. Series 3, Bicarpellatae,
has generally a superior ovary and usually two carpels. It contains 24
orders in 4 cohorts.

The eight series of Monochlamydeae, containing 36 orders, form groups
characterized mainly by differences in the ovary and ovules, and are
now recognized as of unequal value.

The seven series of Monocotyledons represent a sequence beginning
with the most complicated epigynous orders, such as Orchideae and
Scitamineae, and passing through the petaloid hypogynous orders
(series Coronarieae) of which Liliaceae is the representative to
Juncaceae and the palms (series Calycinae) where the perianth loses
its petaloid character and thence to the Aroids, screw-pines and
others where it is more or less aborted (series Nudiflorae). Series
6, Apocarpeae, is characterized by 5 carpels, and in the last series
Glumaceae, great simplification in the flower is associated with a
grass-like habit.

[v.02 p.0014]

The sequence of orders in the polypetalous subdivision of Dicotyledons
undoubtedly represents a progression from simpler to more elaborate
forms, but a great drawback to the value of the system is the
inclusion among the Monochlamydeae of a number of orders which are
closely allied with orders of Polypetalae though differing in absence
of a corolla. The German systematist, A.W. Eichler, attempted
to remove this disadvantage which since the time of Jussieu had
characterized the French system, and in 1883 grouped the Dicotyledons
in two subclasses. The earlier Choripetalae embraces the Polypetalae
and Monochlamydae of the French systems. It includes 21 series, and
is an attempt to arrange as far as possible in a linear series those
orders which are characterized by absence or freedom of petals. The
second subclass, Gamopetalae, includes 9 series and culminates
in those which show the most elaborate type of flower, the series
Aggregatae, the chief representative of which is the great and
wide-spread order Compositae. A modification of Eichler's system,
embracing the most recent views of the affinities of the orders of
Angiosperms, has been put forward by Dr. Adolf Engler of Berlin, who
adopts the suggestive names Archichlamydeae and Metachlamydeae for the
two subdivisions of Dicotyledons. Dr. Engler is the principal editor
of a large series of volumes which, under the title _Die naturlichen
Pflanzenfamilien_, is a systematic account of all the known gen