Keeping constantly in mind the dynamic structure of 
nature, [ shall attempt to examine the Orchid family 
and its origin against this background. 
FLORAL DIAGRAMS AND BASIC GROUPS 
The Orchid family is an extremely heterogeneous unit 
with respect to its external and internal composition. The 
vast array of types of modified structures, many of which 
combine simultaneously characters of both a primitive 
and advanced nature, are, however, tied together by a 
few definite characteristics: 1, the inferior ovary; 2, the 
production of a large number of seeds without endo- 
sperm; and 8, the various degrees of fusion between the 
style and stamens. 
Notwithstanding the large number of species in the 
family, it is possible to outline and express the arrange- 
ment of floral parts by means of three or four basic floral 
diagrams (Plate VIII). From an inspection of these floral 
diagrams, it is evident that orchid flowers are built on a 
trimerous pattern and that they are merely modifications 
of the liliaceous type. The essential deviation from the 
liliaceous pattern is to be seen in the staminal circles. In 
the first diagram (PI. VIII, fig. 1), which may equally 
serve for Ornithogalum of the Liliaceae or Hypoais of the 
Hypoxidaceae (A marillidaceae sens. lat.), both staminal 
circles are fertile and fully developed, i.e., all six anthers 
are functional. In the Orchidaceae (PI. VIII, figs. 2-4) 
the anthers opposite the lateral sepals and the median 
petal are completely suppressed (with the exception of 
Satyrium, about which more will be said later). ‘The re- 
duction in number of fertile anthers is always paralleled 
by a fusion of the stamens and of the stamens with the 
style. Developmental and anatomical investigations with 
respect to the origin of these fertile circles indicate that 
the existing species must have evolved along at least two 
different lines from an already modified ancestral type, 
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