166 ’ ELEMENTS OF BOTANY. 
205. Protection of Pollen from Unwelcome Visitors. —It is 
usually desirable for the flower to prevent the entrance of 
small creeping insects, such as ants, which carry little pollen 
and eat a relatively large amount of it. The means adopted 
Fig. 148. Flowers protected from Unwelcome 
Visitors. 
I, enchanter’s nightshade, magnified five times; 
II, gooseberry, natural size; III, tellima, 
magnified two times; IV, speedwell, magni- 
fied four times; V, bearberry, magnified six 
times; VI, hound’s-tongue, magnified four 
times; VII, nodding campion, natural size, 
at midnight. 
to secure this result are 
many and curious. In 
some plants, as the com- 
mon catchfly, there is a 
sticky ring about the 
peduncle, some distance 
below the flowers, and 
this forms an effectual bar- 
rier against ants and like 
insects. Very frequently 
the calyx-tube is covered 
with hairs, which are 
sometimes sticky, as in 
Fig. 148, I, Il, and VII. 
How these thickets of 
hairs may appear to a 
very small insect can per- 
haps be more easily real- 
ized by looking at the 
considerably magnified 
view of the hairs from 
the outer surface of 
mullein petals, shown in 
Fig. 149.1 
Sometimes the recurved 
petals or divisions of the 
corolla stand in the way 
of creeping insects, as in III and VII. In other cases the 
throat of the corolla is much narrowed, as in V, or closed 
1 On protection of pollen see Kerner and Oliver, vol. II, pp. 95-109. 
