SWEET-CLOVEK SEED. 
5 
attacked to the staminal tube ; the petals may be bent downward 
sufficiently far so that many different kinds of insects may secure 
without difficulty the nectar secreted around the base of the ovary. 
The fingerlike processes of the alae are appressed closely to the 
carina, therefore the alse are bent downward with the carina by 
insects. These processes grasp the staminal tube superiorly and 
tightly when the carina and alas are in their natural positions, but 
when the carina is pressed downward by insects the fingerlike proc- 
esses open slightly but not so far that they do not spring back to their 
original position when the pressure is 
removed. The staminal tube splits 
superiorly to admit the tenth free 
stamen. The filament of this superior 
stamen lies along the side of this 
staminal tube. The filaments of the 
nine stamens which compose the stami- 
nal tube separate in the hollow of the 
carina. All stamens bear fertile an- 
thers. The pistil is in the staminal 
tube, the upper part of the style and 
stigma of which is inclosed with the 
anthers in the carina. The stigma 
is slightly above the stamens. 
An insect inserts its head into a 
sweet-clover flower between the vexil- 
lum and carina, the stigma, therefore, 
comes into direct contact with the 
head of the insect and cross-pollination 
is effected. At the same time the an- 
thers brush against the insect, so that 
its head is dusted with pollen, to be 
carried to other flowers. 
Fig. 2. — Lengthwise sectional view of a very 
young flower of Melilotus alba, showing the 
relative development of the stamens and 
pistil. In the upper set of stamens the di- 
visions of the mother cells are completed, 
while division is just beginning in the 
lower set of stamens. In the ovules the 
outer integuments are well started on their 
development, a, Anther; o, ovule; p., 
pistil. X38. 
DEVELOPMENT OF THE FLORAL ORGANS OF SWEET CLOVER. 
The stamens of Melilotus alba and M. officinalis may be divided 
into two sets, according to their length and time of development. 
(Fig. 2.) The longer set extends about the length of the anthers 
above the shorter set, and the pollen mother cells in the longer set 
divide to form pollen grains at least two days earlier than those in 
the shorter set. At the time the pollen mother cells divide, the 
longer set of stamens is approximately three-eighths of a millimeter 
in length and the pistil about half a millimeter long. The stigma 
and a portion of the style project beyond the stamens, and this rela- 
tive position is maintained to maturity. The pollen mother cells 
undergo the reduction division while the megaspore mother cells are 
