32 Field, Forest, and Wayside Flowers 
But the pollen grains which are to be entrusted 
to insect messengers are often sticky or roughened 
all over with little points, so that they catch on 
the hairy bodies of their winged porters, and cling. 
The interdependence between flowers and their 
guests has lasted for so many generations, that 
certain insects have modified their chosen blossoms 
somewhat, and the flowers, in their turn, have 
modified their messengers. Thus there have come 
so be hereditary friendships in the outdoor world, 
to strong and so enduring that Delphino, who 
gave the subject much study, has made a rough 
classification in which flowering plants are graded 
“‘according to the company they keep.’’ 
His ‘‘ first class’’ are adapted for the larger 
bees. They have diurnal flowers, with colors and 
scents attractive to man also. 
Flowers of the second class are the particular 
friends of the lesser bees, though they also show 
hospitality to many other small insects. ‘‘ These 
flowers,’’ says Delphino, rather disparagingly, ‘‘ have 
quite incomprehensible attractions for their visitors.’’ 
The third class comprises the big-fly flowers. 
These are often in dull shades of yellow and red, 
and exhale an odor disagreeable to man and to 
bees. 
