A MANUAL OF BOTANY 49 



same kind, cross-pollination. From your observation and 

 reading what different methods or agents are there that can 

 accomplish this ? Upon what agent does the willow de- 

 pend ? (See staminate study.) 



After pollination comes fertilization. The pollen grains are 

 lodged in some manner upon the stigma, germinate and send 

 the growing tube seen in your pollen study through the 

 style into the cavity of the ovary, where it enters one of the 

 tiny ovules there contained, fuses with the egg cell, and a 

 seed, after some growth, is the result. 



Comparative work. Compare, if possible, cotton wood or 

 poplar flowers with those of the willow and observe the 

 resemblances and differences. 



Written work. Write careful description of each catkin, 

 flower, and the pollen. 



The willow family. The willow is the type of the icillow 

 family, consisting of common shrubs and trees, and having, 

 as common examples, all kinds of willows, poplars, cotton- 

 wood, and "Carolina poplar." Of what value are any of 

 these ? 



Applications. (1) Take some poplar wood, cut up into 

 small blocks, and soak for 24 hours in 10 % sulphuric acid. 

 Now by means of a heavy hammer crush the blocks until 

 thoroughly pulped. You have crudely accomplished one 

 stage in paper making from wood (poplar and spruce). 



(2) Take a number of willow blocks, place in any small 

 iron dish that can be closed tightly, heat red hot for 20 

 minutes, and allow to cool. Examine the wood. You have 

 made charcoal. \Vhy did not the wood burn up ? 



(3) In spring place several willow twigs in water or earth. 

 Notice the roots forming on the willows in water; also that 

 the willows in the earth begin growth. These plants may 

 be easily propagated in this manner. 



(4) If possible, observe the action of bees around stami- 

 nate willows. What do they obtain from the flowers ? 



