218 PRACTICAL COURSE IN BOTANY 
insect visitors by its conspicuous appearance? What is the 
use of the projecting underlip? Is it any convenience to a 
bee, for instance, to have a platform to rest on while gather- 
ing pollen or honey? What is the use of the arched upper 
lip? Cut it away and notice the exposed condition of the 
stamens and pistil. Turn a flower upside down; what 
would be the effect on a visiting bee or butterfly? (Exps. 
83, 84.) 
244. Morphology of the flower. — We have seen that the 
venation of petals and sepals corresponds in a general way 
with that of foliage leaves of the class to 
which they belong, and that their arrange- 
ment around their axis is analogous to the 
arrangement of foliage leaves on the branch. 
In our study of 
inflorescence, it 
was observed that 
flowers and flower 
buds occur in the 
same _ positions 
where leaf buds 
occur, and that 
they are subject 
Fic. 327.— Staminodia, trans- 
formed stamens of canna simu- tO the same laws 
arrangement ad 
Fie. 328.— 
and growth. We fiower of a cactus 
learned, also, in our study of leaves, some- (cereus | greggi, 
thing about the wonderful modifications that from Salen ta 
these organs are capable of undergoing; and ?¢™s 
finally, an examination of a number of different flowers has 
shown them capable of undergoing modifications to an equal 
or even greater extent, and examples of the transition of 
almost any floral organ into another may be observed by one 
who will take the trouble to look for it. Stamens and petals 
are found in all stages of transformation, from the slightly 
flattened filament of the star-of-Bethlehem, or the yellow 
lating petals: pet, petals; st, of 
staminodia. 
