Abstract
Healthy tulip plants of the variety William Pitt were inoculated at blooming time with sap expressed from diseaed leaves of the following varieties: (a) Lincolnshire showing color-removing type breaking, (b) Feu Brilliant showing color-adding type breaking, and (c) William Pitt showing typical breaking, i. e., mixed color-removing and color-adding. In the following year, all the flowers of the inoculated William Pitt plants showed typical breaking, irrespective of the type of inoculum. It seems that various types of breaking in tulip flowers are not due to the kind of virus, but are rather due to genetic characteristics of tulip varieties.
