218 
THE LIFE OF FLOWERING PLANTS 
which may not be in the same flower or even on the same 
plant. Other parts are merely accessory, being found in 
those flowers which depend on insects' for cross-pollination. 
Large, showy flowers are not grouped; but small, incon¬ 
spicuous ones are, to attract insects. Pollen which is dis¬ 
tributed by wind is very light and very abundant. Stigmas 
which depend on wind for pollination are plumy or sticky or 
both. Fertilization of the egg cell in the ovule is accom¬ 
plished when the sperm nucleus in the pollen, grain unites 
with that of the egg cell. A flower may be defined as a 
device to secure pollination. 
QUESTIONS 
Into what two groups may the organs of a plant be divided ? What 
organs are in the first group? What in the second? Name all the 
parts that a flower may have. Tell the use of each part. What are 
some of the adaptations of flowers that attract insects to them ? What 
peculiarities have flowers that are pollinated by the wind? What 
is fertilization? 
REFERENCES 
Bessey, College Botany, page 285; pages 302-313; 321-324. 
Snyder, General Science, pages 200, 201. 
Bergen, Foundations of Botany, 186-216. 
Conn, Biology, page 118. 
Bergen and Caldwell, Practical Botany, pages 104-135. 
Gibson, Sharp Eyes, page 115. 
Coulter, Plant Life and Plant Uses, page 58; pages 258-321. 
