PREFACE 



These laboratory directions represent the outline of the lab- 

 oratory course in general zoology as developed in the University 

 of Illinois. The original plan of the course was formulated by 

 Professors Henry B. Ward and Charles Zeleny. Individual out- 

 lines throughout the course represent the work and suggestions 

 of numerous persons who have, at various times, been connected 

 with the instructional staff in general zoology. The form found 

 in the present volume is the result of many revisions and altera- 

 tions of the several mimeographed and printed editions which 

 have been used with classes through a period of a considerable 

 number of years. In recent revisions the cooperation of Profes- 

 sor V. E. Shelford has been especially valuable. 



An attempt has been made to secure a fair distribution of 

 emphasis through a number of the more important aspects of 

 the subject. 



The directions are so organized that the field work and lab- 

 oratory study based upon it may be used either at the opening or 

 toward the close of the course, depending upon the time of year 

 when the course is started. More work is outlined than is usually 

 covered in a half year course, thus allowing some choice of ma- 

 terials on the part of the instructor. A number of the outlines 

 are intentionally brief. These offer opportunity of directing the 

 student in a comparative study of forms closely related to others 

 which have been treated in greater detail. 



The writer is indebted to Professor S. H. Gage for the use 

 of the figure of the compound microscope. 



H. J. VAN CLEAVE. 



Zoological Laboratory, 

 University of Illinois. 

 Urbana. 



