Virus Diseases In Plants:I. TRANSLOCATION WITHIN THE PLANT. II. THE AMOEBOID INTRACELLULAR INCLUSIONS.

Summary. In virus disease in plants, abnormal inclusions, found only in such disease, are frequently found inside the cells. Of these inclusions one type has characters which have led to the belief that it may be a living amoeba‐like organism, a phase in the life‐history of the virus parasite. This type, the “X‐body,” is fully described and the evidence for its parasitic nature set out. The alternative view is that these bodies are not living organisms but are a reaction‐product of the cell to the virus irritant. This seems, on the whole, more probable, and is supported by some recent work in which formation of the bodies has been watched in the individual cell from their beginning to their completion, the method of formation accounting for the appearances which have suggested that the bodies are independent organisms.