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EVOLUTION AND ANIMAL LIFE 



Collect a few thousand individuals, at one time in one place, 

 of a single species of insect, as a spotted ladybird beetle; then 

 go over these carefully, looking for variation in some single 

 characteristic, as the color pattern. What do you find? Let us 



FIG. 72. Diagram showing variation in elytral pattern of the convergent ladybird, 

 Hippodamia convergens : 1, Mode; 2-9, variations in size of spots; 10-17, variations 

 by coalescence of spots; 18-40, variations by reduction in number of spots. (After 

 Kellogg and Bell.) 



