Para-crinkle: a potato disease of the virus group

The investigations here recorded were prompted by the confirmation, early in 1928, of observations made by the senior author in 1927, that when apparently healthy King Edward plants were grafted on to the two test plants, President and Arran Victory, the latter succumbed but the former did not. This work, so far as it was directed toward the elucidation of this particular phenomenon and its relation to a new disease entity, was initiated by both authors and proceeded actively till March, 1929, when the junior author left to take up the post of Entomologist in Kenya. Since then the senior author has continued the study and is alone responsible for the presentation of the work and the deductions as they now appear.