SUMMARY
An equation was developed to describe the relation between the numbers of infections given by inoculation of host plants with virus suspensions and the relative concentration of the suspensions. It was of the form y=N (1-e-m), where y was the number of infections, N the maximum possible number of infections, e the base of natural logarithms, and m the ratio of virus units entering and causing infection to the total number of entry points, leaves, or plants (according to the unit used for judging infection).
The function m was expanded for the particular case of dilution experiments.
Methods of fitting the data obtained from dilution experiments were discussed.
The data from seven dilution experiments with carefully purified samples of four viruses (infections reckoned as lesions) were fitted with equations of the form given above, and were found to agree fairly well with the calculated values.
Two types of distortion in the dilution series were illustrated.
The significance of the maximum N was discussed.
The same data with y as the number of leaves infected were found also to agree with the equation.
[1]
W. M. Stanley,et al.
ISOLATION OF A CRYSTALLINE PROTEIN POSSESSING THE PROPERTIES OF TOBACCO-MOSAIC VIRUS.
,
1935,
Science.
[2]
K. Smith,et al.
A Description of a Necrotic Virus Disease affecting Tobacco and Other Plants
,
1935,
Parasitology.
[3]
J. Bald,et al.
Some Factors Affecting the Inactivation Rate of the Virus of Tomato Spotted Wilt
,
1934
.
[4]
D. Macclement.
Purification of Plant Viruses
,
1934,
Nature.
[5]
G. Samuel.
Some Experiments On Inoculating Methods With Plant Viruses, And On Local Lesions
,
1931
.
[6]
B. M. Duggar,et al.
The Sizes of the Infective Particles in the Mosaic Disease of Tobacco
,
1921
.