FOR WAGGONER’S BIOLOGY 
31 
EXERCISE 34 
ALG^ 
The algae for this exercise should be collected before cold 
weather begins or obtained from some biological supply house. 
I. Spirogyra (Green Algae). 
1. In what kind of location does spirogyra grow? What have 
you observed about its abundance? When in the year is this 
abundance greatest? What is the appearance of this alga to the 
naked eye? Its color? To the presence of what substance is 
this color to be attributed? 
2. Study a few strands of spirogyra which have been mounted 
under the low power and others which have been mounted under 
the high power of the microscope. Of what is a single filament of 
spirogyra composed? What is the shape of one of the cells of 
which the filament is composed? (See Waggoner, Fig. 98.) Where 
do you find the chlorophyll in the cell? How many bands do you 
see? Describe their position in the cell. 
II. Protococcus. Where is this alga found? Explain why it is 
more abundant on the north than on the other sides of tree trunks. 
Study some of the Protococcus which has been mounted under the 
microscope. What is the color? How many cells seem to be 
joined together? Make a series of drawings showing different 
groups of the cells of the Protococcus. 
EXERCISE 35 
BREAD MOLD —MUCOR 
After moistening pieces of bread in water, place them in dishes 
which have close fitting covers. To be certain that mold spores 
will be present, shake a duster over the bread before covering. 
Keep the dishes in a warm room for two or three days. 
I. Note the appearance from day to day of the mold which 
grows upon the moist bread. This mold is probably Mucor or a 
nearly related type. What is its appearance to the naked eye? 
