148 
MANUAL OF NATURK STUDY. 
pupils will notice tliat all these flowers are more or 
less irregular both as to arrangement of stamens 
and pistils and as to floral envelopes. They can 
also be led to see that whenever an irregularity in- 
j ures the chances to self-fertilization it at the same 
time facilitates insect-fertilization. 
The author is not quite sure that the statement just 
mentioned is always true, but it surely is true in 
many cases. For instance, the showy strap-shaped 
corolla of the sunflower advertises the nectar in the 
slender tubes of the flowers within, and thus the in¬ 
sects are attracted in great numbers. The lower 
lip of a gamopetalans corolla serves as a resting place 
for the bee, while it gathers the nectar within. The 
stamens of the horse-chestnut protrude in such a 
way as to form a perch for the bumble-bee while 
he sinks his suction pump down into the nectar, 
and while doing so, does not pollen cling to his legs, 
to be deposited upon the. stigma of another flower 
which he is soon to visit ? It will be observed that 
in such flowers the stigma and anthers of the same 
flower are seldom ready for fertilization at the same 
time. The stigma of one flower visited by the bee 
is withered, and therefore in a non-receptive condi¬ 
tion, while the pollen, ready to perform its part in 
the process of fertilization, clings to the legs of the 
bee, and is thereby transferred to a receptive stigma 
in another flower, the stamens of which are not yet 
