CONTENTS 
PAGE 
Introduction .xv 
CHAPTER I 
Zoological Position, Life History, and Habits i 
Life History. 6 
The Egg.18 
The Larva.19 
The Pupa and Puparium.23 
Emergence of the Adult.25 
Structure of the Adult.27 
Difference in Size of Adults.32 
Summary of Duration of Life Round . . 35 
Number of Generations.36 
Possibilities in the Way of Numbers . . 37 
Number by Actual Count in Relation to 
Quantity of Food.39 
Hibernation.41 
Habits of the Adult Fly.44 
Do Flies have a Color Preference? ... 47 
Fly-Specks.48 
Distance of Flight.51 
Marking Flies for Experiment .... 56 
Length of Life of the Adult.58 
Time Elapsing between the Issuing of the 
Adult and the Period of Sexual Maturity 60 
