PREFACE. 



The course of study outlined in the following pages is de- 

 signed to enable students to learn the more general features 

 of the structure of insects. It has been prepared especially 

 for students who devote only a short time to entomology ; 

 it may serve, however, as an introduction to a more ex- 

 tended study of the morphology of insects. Students mak- 

 ing a special study of entomology will be assigned more ad- 

 vanced work after they have completed this elementary 

 course. 



While the more obvious object of this course is the learn- 

 ing of certain facts, a much more important thing to be 

 gained is a training in methods of careful observation. The 

 student is urged, therefore, to do the work with great care. 



Chapters IV, V, and VI have been written by Professor 

 Kellogg ; the remainder of the work, by the senior author. 



