The studies here described aim at the elucidation of the action of a plant virus within the insect that is its specific vector. It is widely held that insect transmission is not normally a mechanical process; but of the nature of the biological relation, into which virus and insect are supposed to enter, little is definitely known. By the use of the method of mechanical inoculation of the virus into the insect I have obtained certain direct evidence bearing upon this problem. The virus studied is that which causes streak disease in the maize plant. A single strain has been used, maintained in the course of my experiments by repeated transfers to maize seedlings in the greenhouse. Conceivably this strain is a complex of viruses, but if so it has shown no sign of splitting into its components during the period of the work now described.
Investigations of the mechanism of the transmission of plant viruses by insect vectors.— I