ORCHIDS 299 
is said to be “inferior.” The nearly related Iris has its 
sepals reflexed and its petals erect: its stamens are three, 
and the three style branches are broad and spreading. 
The ovary is inferior as in Amaryllis. 
'  §45. Orchids (Orchidales). Here the ovary is in- 
ferior as in Amaryllis, but the 
perianth is made up of unequal 
and unlike segments, the stamens &) 
are reduced to two or one (very \ 
rarely three), and the tricarpel- a 
lary pistil has but two functional 
} ; tari Fie. 172.—Orchids (Cypri 
stigmas in the large majority of Lt aint =a hate at 
species. 
546. In all the foregoing Monocotyledons the embryos 
have one cotyledon, the stems have scattered vascular 
bundles, the leaves are alternate on the stems, and paral- 
lel-veined, and the perianth whorls are ternate. 
Laboratory Studies. Norr: In these studies, and those 
upon Dicotyledons, the aim should be to bring out the succes- 
sive advances in flower structure from the lower to the higher 
forms. With this object in view many other details may well 
be omitted, but some attention should be given also to special 
modifications of the general plant body. 
(a) Make cross- and longitudinal sections of onion seeds and 
note the seed coats (integuments) enclosing the rather horny 
endosperm within which lies the embryo sporophyte. In 
similar sections of grains of Indian corn the external coat con- 
sists of the ovary wall grown fast to the integuments; the 
remainder of the grain consists of endosperm except the elon- 
gated or shield-shaped ‘‘germ,” which is the embryo sporo- 
phyte. 
(b) Sow a number of onion seeds and grains of Indian corn 
and examine one of each every day after germination begins. 
In the onion note that the plantlet ‘backs out” of the seed, as 
it were, the root first appearing, followed by the stem, and last 
of all, the single cotyledon. In the corn the cotyledon remains 
in the grain as a special absorbing organ, so that after the root 
