INTRODUCTION 



IT is only within the last twelve years that the dan- 

 gerous character of the common house fly has been 

 known; and only within the last two years have the 

 people at large begun to wake up to this danger and 

 to inquire concerning the means by which this fly can 

 be kept down. The writer published some account 

 of its life history in a bulletin on household insects 

 published by the U. S. Department of Agriculture in 

 1896. Later he made some experiments with regard 

 to remedies, and in 1900 published a rather lengthy 

 paper on the insect fauna of human excrement with 

 especial reference to the carriage of typhoid fever by 

 flies. Within the last two years, however, articles 

 relating to the so-called house fly in connection with 

 its disease-carrying possibilities have been published 

 literally by the thousand, and this interest, perhaps 

 having its origin in the United States, has spread to 

 nearly all parts of the civilized world, and yet in no 

 one of these published articles is the whole story told. 

 No one can find in condensed and convenient shape 

 the general information he desires in regard to this 

 insect. The pubHshers of this book, realizing this fact, 

 have invited the author to attempt to fill this want. 



This book is not intended to be a scientific mono- 

 graph ; it is simply an attempt to tell in an understand- 

 able way what is known about the subjects indicated 

 in the title. 



XV 



