238 CRYPTOGAMS 



can enter at fertilization. Where is this pore situated? 

 (6) The short bent antheridium or male reproductive 

 organ. 



Let the material remain in a warm place and cover to 

 prevent drying out. Under favorable conditions the zoo- 

 spores or sperms will develop and may be studied under a 

 high power. They escape from the antheridium and swim 

 about by means of pairs of delicate cilia or lashes. A drop 

 of iodine solution is needed to show these organs. 



Fertilization is effected when a sperm swims into the 

 pore of the oogonium and fuses with the egg. 



Look for the ripened egg or oospore within the oogonium. 

 How do the walls and contents differ from that of an un- 

 fertilized egg? 



This method of reproduction is known as heteroyamy, 

 because the sex elements are unlike, namely, eggs ( 9 ) and 

 sperms ( $ ) . 



202. BREAD MOLD 

 Object. To study the growth of bread mold. 



Method. Select two wide-mouth bottles. Mason fruit 

 jars with rubber rings and screw tops are best. 



Place a piece of bread or banana skin or a cold boiled po- 

 tato in each jar, and leave it open to the air of a kitchen, 

 pantry, or cellar for five or ten minutes. Then screw on the 

 covers tight, after having added a few drops of water to 

 insure a damp atmosphere within. 



Now plunge one jar into a kettle of boiling water and let 

 it boil for a few minutes. Remove it and stand both jars 

 in a warm place for several days. 



Which jar first shows signs of mold? Why? How long 

 before the other jar shows mold? 



