[Vor. 4 
222 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
development of the disease is arrested sufficiently to sug- 
gest apparent recovery. 
6. Properties of the infective principle substantiate 
the view that the infectious substance is an enzyme 
and not а ‘‘virus.’’ This enzyme is not of the nature of 
the oxidases giving the guaiacum reaction. 
7. The infective principle is greatly adsorbed by tale, 
a phenomenon characteristic of all colloidal compounds 
including enzymes. 
8. There is a specificity of reaction between the infec- 
tive principle or mosaic enzyme and formaldehyde and 
probably with aldehydes in general. 
9. The destruction of the infective principle cannot 
be attributed to the antiseptic properties of formalde- 
hyde, since treatment with concentrated solutions of the 
best antiseptics as ether, chloroform, carbon tetra- 
chloride, toluene, acetone, and glycerin does not destroy 
the infectious properties. 
10. The infectious properties are destroyed by con- 
centrations of alcohol which are destructive to enzymes. 
11. The temperatures which destroy the infectious 
properties are the same as those which inactive enzymes 
or hydrolyze some organic compounds. Cooling has no 
greater effect on such properties than is exerted on any 
chemical compound, including enzymes. 
12. The reproduction of the mosaic enzyme сап be ас- 
counted for on purely physiological grounds, but the 
factors which originally induced its formation are still 
unknown. 
13. Тһе specificity of reaction of the mosaic enzyme 
with formaldehyde and the unbalanced carbohydrate rela- 
tion between lighter and darker areas, combined with the 
contention that formaldehyde is one of the first products 
of photosynthesis, suggest a basis upon which the physio- 
logical nature of mosaic diseases may be explained. 
14. The continued production of the mosaic enzyme 
in inoculated plants is in accord with the fundamental 
principles of pathology and physiology. 
