\ 
THE INVESTIGATIONS of the cucumber mosaic reported 
in this paper were begun by the writer in 1914 at Hamilton, 
Mich., while a graduate student at the Michigan Agricultural 
College. In 1915 and 1916 they were continued at Big Rapids, 
Mich., and in 1917-18 at Madison, Wis., under cooperative 
relations between the Bureau of Plant Industry of the United 
States Department of Agriculture, the experiment stations of 
Michigan and Wisconsin, and certain interested pickle growers, 
under the joint direction of Dr. E. A. Bessey, Dr. L. R. Jones, 
and Mr. W. W. Gilbert. Laboratory facilities and material 
were furnished jointly by the cooperating parties and land, 
tools, and labor by a local pickle company. 
The writer wishes especially to thank Messrs. Bessey, Jones, 
and Gilbert for assistance and supervision throughout the 
course of the work. 
This paper was presented to the faculty of the University of 
Wisconsin in partial fulfillment of the requirements for the 
degree of doctor of philosophy. 
