POLLINATION OF FLOWERS 
679 
the resemblance is not very apparent. 
There are also malodorous flowers which 
are yellowish or green. It is chiefly the 
nauseous odors which draw to flowers car¬ 
rion or dung-flies belonging to the genera 
Musca, Lucilia, Calliphora and Sarco- 
phaga. Many strong-scented odors are also 
attractive to flies. Common carrion flow¬ 
ers are the carrion-flower ( Smilax herba- 
cea), the purple trillium, and the water 
arum ( Calla palustris). 
The spotted arum ( Arum maculatum ) is 
a prison flower, and, like all the Aroids, has 
an offensive odor. Small flies can easily 
pass downward into the bulbous cavity at 
the base of the sheathing leaf, or spathe, 
but for a time are prevented from return¬ 
ing by the ring of bristles inclined down¬ 
ward. After they are covered with pollen 
the bristles wither and the midges escape. 
As many as 1,000 midges may be impris¬ 
oned in a single spathe. The common Jack- 
in-the-Pulpit, or Indian turnip, is a pitfall 
flower. The inner side of the spathe or 
“pulpit” is smooth, shining, and very slip¬ 
pery. When little moth-like flies ( Psy- 
choda) rest on this polished surface they 
cannot get a foothold, and fall into the 
chamber below. The staminate and fertile 
flowers are on separate plants. The stam¬ 
inate flowers are visited first since they 
bloom first. As the spathe withers, the in¬ 
ner surface relaxes and becomes rougher, 
enabling the little visitors, now loaded with 
pollen, to escape and fly to the pistillate 
flowers. The spathes of the latter wither 
less promptly, and many of the little flies 
perish in the chamber. Another prison 
flower is the Dutchman’s pipe. 
The bee-flies (Bombyliidae) , which are 
often mistaken for bees, live wholly on 
nectar, but the Syrphid or hover-flies 
(Syrphidae), feed on both pollen and nec¬ 
tar. They are very common visitors to 
flowers and are usually dotted or striped 
with yellow. In New Zealand where there 
were, at the time of their discovery, no 
bumblebees nor honeybees and only a few 
solitary bees, flies were the most important 
visitors among the native insects. 
Butterfly-Flowers. — Butterflies were call¬ 
ed by Jean Paul “the flowers of the air.” 
As they do not collect pollen but feed on 
nectar alone they are of far less importance 
as pollinators than bees, and much less con¬ 
stant in their visits. The tubular probos¬ 
cis or tongue, which is carried coiled be¬ 
neath the head, is formed by the extension 
of the blades of the maxillae, or second pair 
of jaws, which are held together by minute 
hooks. 
Common butterfly-flowers are the pinks, 
various primroses, lilies, and orchids, and 
some species of phlox. The floral tubes 
are so long that the nectar is far beyond 
the reach of bees. It is also noteworthy 
that the color of butterfly-flowers is usu¬ 
ally red, the color of many butterflies; but 
in the genus Phyteuma there occur blue 
butterfly-flowers which are visited by blue 
butterflies. 
Butterflies do not confine their visits to 
butterfly-flowers, but visit a great variety 
of blossoms. They experience more or less 
difficulty in sucking nectar from flat sur¬ 
faces, and consequently prefer tubular 
flowers. But no flowers are so frequently 
visited by butterflies, as social flowers of 
-the type of the Compositae, to which 40 to 
60 per cent of their visits are made. Clouds 
of butterflies often hover over a clump of 
purple thistle-heads, or the yellow flowers 
of elecampane ( Inula Helenium) , or the 
dull white clusters of the thoroughwort. 
Butterflies often rob flowers of their nec¬ 
tar thru crevices or openings in the corolla 
without rendering any service in return. 
Nocturnal or Moth-Flowers. — Nocturnal 
flowers are adapted to pollination by moths, 
chiefly hawk-moths. In their relation to 
flowers moths may be divided into two 
groups, the highly specialized hawk-moths 
(Sphingidae) and the other moth families. 
Among the smaller moths frequently ob¬ 
served on flowers are the measuring moths, 
leaf-rollers, owlet moths or noetuids, and 
the teneids. Few of them are common 
floral visitors or of much significance in 
pollination. 
The yuccas or Spanish bayonets, lilia¬ 
ceous plants, which are widely distributed 
in this country and Mexico, are entirely 
dependent for pollination on little teneid 
moths of the genus Pronuba. The large 
creamy-white flowers are borne in magnifi¬ 
cent clusters, which never fail to excite ad¬ 
miration. As the large bell-shaped flowers 
hang downward,and the stamens are longer 
