REPRODUCTION 49 
LESSON XXVI 
Reproduction by seeds—the flower and seed 
Materials—An abundance of any simple flowers, as 
those of Potentilla or Anemone. If this is a winter study, 
and greenhouse specimens are not convenient, good ma- 
terial may often be obtained by standing branches of peach 
and apple trees in vessels of water and placing them near 
a window in a room in which the temperature is kept at 
about 70° Fahrenheit. It will be very much better, how- 
ever, to plan the work so that these lessons will come at a 
time when wild flowers may be found. 
Observation and study.—The whole flower is concerned 
in the process of reproduction, some of the parts acting 
directly and others indirectly in this work. Locate and 
make sketches illustrating the parts of the flower as follows: 
1. The calyx, which is the outermost set of leaf-like parts 
of the flower. Each leaf-like member is a sepal. Usually the 
entire set is green. In a good many flowers the calyx is not 
present, or is not differentiated from the other structures. 
Is it present in the flower of the plant you have? Sepals 
may be in cycles (several placed at the same level on the 
stem) or may be in spirals. How are they arranged in this 
plant ? 
2. The corolla. This is the next set of floral leaves, and 
is usually colored. Each member of the corolla is a petal. 
When the floral leaves are not differentiated into calyx and 
corolla these names are not used to designate them, but the 
term perianth is used instead. If the parts are in cycles, 
how many cycles of the corolla are there present, and how 
many petals in each cycle? : 
3. The stamen set. How many cycles, and how many 
stamens in each cycle? Draw one stamen showing the elon- 
gated part, the filament, and the swollen tip, the anther. 
Open an anther and note the dust-like pollen-grains within 
