Grasses 161 
As grass-flowers send their pollen abroad only by 
the wind, they have no need to lure insect messen- 
gers, and hence have no striking colors, and, in 
most cases, no perfume. They are generally very 
small, and are massed together in compact groups, 
Fic. 39.—Ligula of millet-grass. 
(From the Vegetable World.) 
which live in close propinquity to other groups, 
forming large floral communities. 
The oat of commerce is a typical grass, and 
from a study of its parts one can gain knowl- 
edge on the structure of grasses in general. 
To a casual glance there is little difference be- 
