No. 390.] MONOCOTYLEDONOUS FLOWERS. 503 
SUMMARY. 
1. The primitive color of the perianth of the monocotyledo- 
nous families was green, as it still is in the greater part of the 
species which are anemophilous or self-fertilized. A few of 
the oldest families, with an indefinite number of stamens and 
carpels spirally arranged, have probably never possessed floral 
envelopes. 
2. Yellow, white, and lurid, or greenish-purple flowers have 
in numerous instances been derived directly from the primitive 
green ; red flowers have passed through a yellow or white stage ; 
and blue and purple-blue have been derived from yellow, white, 
or red forms. Reversion to white is most common, but rever- 
sion to red or yellow also occurs. 
3. Physiological conditions appear to have often played an 
important part in determining the coloration of the petals, 
while “insects have contributed to the fixation of such charac- 
ters when once acquired.” 
4. In general, among monocotyledons yellow flowers are 
visited by bees and flies; white flowers, by bees, nocturnal 
Lepidoptera, flies, and beetles ; lurid-purple, by flesh flies; red, 
by bees and butterflies; and blue, chiefly by bees. Red and 
blue flowers usually have the honey concealed, which is a far 
more effective cause of the limitation of insect visits than 
color. 
When the honey is abundant and exposed, and the flower 
pleasantly odorous, it may prove attractive to any anthophilous 
insect. In proof of this it may be stated that insects fre- 
quently attempt to visit flowers from which they are excluded. 
I have seen butterflies standing beneath the perianth of /ris 
versicolor and stealing the honey, without rendering any ser- 
vice in return; an hymenopter, probably an ichneumon fly, was 
observed, but not caught, examining the center of the flower 
for nectar, and of course, unsuccessfully ; flies are attracted by 
the bright colors of /mpatiens biflora to the outside of the 
calycine sac, and I have often seen Philanthus solivagus flying 
from flower to flower of Chelone glabra and examining the lips 
for nectar, but never entering the corolla. 
