VI PREFACE TO THE SECOND EDITION 



States Department of Agriculture, and to Mr. Raymond C. 

 Reed and Mr. Floyd R. Wright, Instructors in the Department 

 of Bacteriology in Cornell University. Suggestions and criti- 

 cisms which may tend to increase the usefulness of these 

 outhnes are cordially invited. 



V. A. M. 

 Ithaca, N.Y. 

 June, 1900 



