FOR WAGGONER’S BIOLOGY 
57 
EXERCISE 61 
VARIATION 
Use materials which were collected for this purpose during the 
fall months. The points of the great ragweed seeds (see Exercise 
9, Part IV) or the notches of ehn leaves may be counted. If no 
preparations have been made in advance for this exercise, the pairs 
of immature leaves in the buds of lilacs may be counted. (Care 
must be used in avoiding any confusion of outer bud scales with 
the leaves which they enclose.) 
I. Divide the ragweed seeds or elm leaves among the members 
of the class. Let each person separate them into piles and place 
all those having the same number of points or notches in one pile. 
Mark each pile with a slip of paper bearing this number. How 
many specimens are present in each pile? Write this on the slip 
for the pile. 
II. When the individual counts are made, total the results for 
the class. List the resulting numbers in order. What is the least 
number of points found? How many specimens have this number? 
What is the highest number found? How many specimens have 
this number? What number occurred most frequently? Make a 
graph showing the results. 
III. Give other examples of variation which you have observed. 
(Note — See Exercise 74. This may be begun in early spring.) 
EXERCISE 62 
THE AMCEBA 
Study pictures of the amoeba found on charts, on lantern slides, 
and in text book illustrations. Then study specimens present in a 
drop of water which has been mounted under the microscope. 
I. Form. Note the general appearance of the amoeba. What 
do you observe regarding its form? Does this form change? 
