nearly all the manuscript, comparing it with her own unpublished researches on the rat, and has called the author's attention to a considerable number of errors, which have been corrected; she has also supplied much unpublished additional information from her own investigations. Credit is due to Dr. Albert M. Reese of West Virginia University for having suggested that the author write this manual, and for much encouragement during its development. 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 nomenclature. I will be very grateful to any critical user of the manual who will report these errors to me.
East Lansing, Michigan.
November, 1924.
