vi PREFACE 



nearly all the manuscript, comparing it with her own 

 unpublished researches on the rat, and has called the 

 author's attention to a considerable number of errors, which 

 have been corrected; she has also supplied much unpub- 

 lished additional information from her own investigations. 

 Credit is due to Dr. Albert M. Reese of West Virginia Uni- 

 versity for having suggested that the author write this 

 manual, and for much encouragement during its devel- 

 opment. In addition, the writer wishes to thank Mr. 

 Frazier Cochrane of Milligan College, and Mr. Joseph W. 

 Stack of the Michigan Agricultural College, for reading 

 the manuscript. 



There are doubtless a few errors in fact and nomencla- 

 ture. I will be very grateful to any critical user of the 

 manual who will report these errors to me. 



HARRISON R. HUNT. 



East Lansing, Michigan. 

 November, 1924. 



