6o8 
Journal of Agricultural Research voi. xxvi, no. 12 
free from the bodies, and the host nuclei seem to show little or no ab¬ 
normality when the bodies are in the cells. Further light may be thrown 
on these points when the relation between the intracellular bodies and 
the internal lesions, described earlier, is determined. 
The intracellular bodies in wheat are similar to certain of the intra¬ 
cellular bodies associated with other plant diseases and with certain 
animal diseases, but they differ in a number of particulars from certain 
others which have been described in diseased tissues. These compari¬ 
sons will be taken up in a later paper. 
POSSIBLE NATURE OF THE INTRACELLULAR BODIES 
The studies made to date show clearly that the bodies in question are 
not artifacts and that their nature is such that they do not yield readily 
to definite interpretation. While it is possible that the bodies may be 
organisms, it is also possible that they are the result of the reaction of 
the host cells to the disease. A rather comprehensive study of the 
literature shows that there are several possibilities in connection with the 
latter interpretation, some of which are more plausible than others, but 
a considerable amount of comparative study must be made before these 
interpretations can be definitely accepted or rejected. 
While it is recognized that the intracellular bodies associated with 
wheat rosette and leaf mottling may be a stage of some definite parasite, 
it is also recognized, on the basis of the cytological studies made thus 
far, that the distribution of the intracellular bodies in the host tissue 
and their apparent parallel development with that of the host cells do 
not seem to conform exactly with the distribution and development of 
any plant parasite known. 
In general, the intracellular bodies in question resemble the cell in¬ 
clusions of unknown nature which are associated with some of the virus 
diseases of animals. This resemblance is especially striking in connection 
with certain of the Negri and Guarnieri bodies which are associated 
with rabies and smallpox, respectively. 
