144 
Fic, 1 
INTRODUCTION TO 
tructure of an ear of corn (pistil- 
late flower cluster) 
1, section of young ear before fertilization of the 
ovules (grains) ; «r, axis of spike (cob) ; si, ends 
of silk (styles and stigmas); 28, magnified sec- 
tion through a grain, showing bracts around the 
ovary, the ovule (0), and the base of the style; 
C, upper portion of style, with the stigmas (st) 
considerably magnified, After F. L. Sargent 
BOTANY 
137. The potato and 
the grape; flowers open 
to all insect visitors. 
The potato is a famil- 
iar example of a flower 
with wide-open corolla 
(fig. 128), easily entered 
by any kind of insect. 
The flowers, with their 
white corollas and con- 
ical group of yellow 
anthers, are moderately 
conspicuous and are vis- 
ited by insects for the 
sake of the pollen which 
they afford. They yield 
no nectar. 
The flowers of the 
grape are small and 
greenish. The corolla 
does not expand but 
falls off in one piece as 
soon as the flower is 
mature. This leaves the 
stamens and pistil ex- 
posed to all kinds of 
insect visitors. Insects 
of various kinds are at- 
tracted by the sweet 
odor of the flowers, and 
find plenty of nectar 
on the nectar glands 
which stand almost un- 
der the ovary between 
the bases of the fila- 
ments (fig. 120), 
