FOR WAGGONER’S BIOLOGY 
5 
III. Which disk florets blossom first? Where do the stamens 
first mature? When do the pistils mature? Explain the signifi¬ 
cance of these differences relative to pollination. 
EXERCISE 6 
POLLINATION, PART I 
This exercise may not only serve the purpose for which it is 
intended, but also be the means, incidentally, of making a collec¬ 
tion of insects for the insect study which occurs later in the year. 
(See Exercises 67 to 72.) The insect specimens which are so col¬ 
lected may be preserved in formalin. (See Appendix.) 
I. Field Study. The class may be divided into small groups, 
and each of these should be supplied with small bottles or cans 
and, if possible, with an insect net. Each group may visit a number 
of different flowering plants and one member of each group may 
act as its reporter. Collect any insects (six-legged animals) which 
are on or in the neighborhood of these plants. Make a careful 
note of the kind of place in which each was found. Bring to the 
laboratory the insects which you collect and specimens of the plants 
in the vicinity of which each insect was found. (To kill the in¬ 
sects, put them in a covered jar containing some cotton saturated 
with gasoline or chloroform.) 
II. Laboratory Study. 
1. Insects. Note the number of the main body divisions of 
the insects collected, the number of wings, and the number of legs. 
Look at the mouth parts of a bee, a butterfly, a fly, and a grass¬ 
hopper. What is the character of each? Why do insects visit 
flowers? 
2. Flowers. Note those which were collected. Is pollen pres¬ 
ent? Examine some grains of pollen which have been mounted 
under a microscope. What characteristics of the pollen make it 
possible for these grains to be distributed by insects? Draw several 
grains of pollen. Indicate from which plant each is obtained. 
(Note — Collect and preserve several dozen locusts (grass¬ 
hoppers) for use in Exercise 67). 
