FOREWORD 



In May, 1918, a class was formed among the entomologists of the 

 country to study the recent developments in the entomology of disease, 

 hygiene, and sanitation, for the purpose of equipping themselves for any 

 special service which they might be called upon to render during the war. 

 The lectures were mimeographed week by week and mailed to the enrolled 

 membership, which numbered in excess of 500. 



The war emergency is over and the mimeographed lectures have 

 practically all been distributed. These lectures, however, dealt as much 

 with domestic as with military problems, and they have now been com- 

 pletely revised up to date of March 1, 1919, and are given forth as a 

 series of lectures dealing with the entomological problems of peace times 

 from the standpoint primarily of municipal, industrial, and household 

 problems, and also with the hope that the course will be of assistance to 

 teachers, and will stimulate research among investigators. Many 

 important topics have been omitted, for we cannot hope to present the 

 whole subject in a book of this size. 



This phase of entomology is one which is destined to become very 

 important as our knowledge of disease transmission increases. There 

 are many unworked and insufficiently worked problems now in sight, and 

 these lectures will be found to suggest numerous possible lines of research. 



I wish at this time to express my appreciation of the services of 

 Mr. Jacob Kotinsky, who served as Secretary of the Class, and of my 

 collaborators in this course of lectui'es. 



As nearly as possible the International Rules of Nomenclature are 

 followed, but in Entomology the practice had not been followed of en- 

 closing the original author's name in parenthasis followed by the name 

 of the author responsible for the present combination, and it has been 

 impossible in the present volume to obtain all of the necessary information. 



W. DwiGHT Pierce. 



