498 THE AMERICAN NATURALIST.: (VoL. XXXIII. 
It has long been a favorite in floriculture and many varieties 
have been produced by hybridization. Seven species with 
yellow, orange-red, and scarlet flowers are indigenous to the 
northern states, and ZL. tigrinus is adventitious from Asia. 
Red flowers are peculiarly attractive to butterflies, and they 
are the chief agents in pollenizing many pinks and species of 
phlox, and, according to Miiller, of Tritoma and the fiery red 
L. bulbiferum. I have repeatedly seen Z. Philadelphicum, 
which is orange-red spotted with purple inside, visited by 
Argynnis aphrodite, the silver-winged butterfly, which is itself 
yellowish-red spotted with silver, but never by any other insect. 
The yellow nodding flowers of Z. Canadense are visited only 
by bees, and I have seen Bombus vagans rest first upon the 
stigma and then climb the stamens to the base of the corolla. 
The white exotic species, such as L. martagon and L. harrisi, 
are sought by Sphingidz or hawk moths. The genera Lilium 
and Tulipa excellently illustrate the transition from yellow to 
red, presenting every intermediate step, as yellow, orange, 
orange-red with a broad yellow band, orange-red, dark scarlet 
with yellow stripes, and fiery red. Tyitoma abraria is coral 
red and, according to Gray, changes to orange and then to 
greenish-yellow. 
Erythronium, Calorchortus, and Muscari are visited by bees, 
and display the most brilliant colors. The 4 native species of 
Erythronium are respectively yellow, white, rose, and lavender ; 
and those of Muscari are blue and white, but under cultivation 
there are also yellow and red forms. 
The genus Yucca is chiefly confined to Mexico and the 
southern states, but 3 species occur north of Tennessee. 
The flowers are large, white above and greenish beneath, and 
are pollinated at night by a white Teneid moth, Pronuda yuc- 
casella A plant in bloom is a magnificent sight, the flower ` 
stalk sometimes, as in Y. filifera of Mexico, rising to the height 
of 50 feet and supporting a panicle 5 or 6 feet long. The 
~ manner of pollination is phenomenal in the extreme and has 
been thoroughly investigated by Riley and Trelease. The 
structure of the moth Pronuba is very abnormal among lepi- 
dopterous insects, as it is provided with tentacles for collecting 
