I'lG. lU. Aggregate.s of the A-pruleiu obtaiuecl i'roni the degradation of tobacco mosaic 

 by detergent treatment. They are seen to liave the same diameter as the virus and to 

 possess a central liole. : : 12(l,0(f(l. 



Fig. 11. Frozen-dried particles of tomato bushy stunt virus. Note that the contours of 

 the particles are not circular, but exhibit some degree of angularity. This virus is most 

 likely polyhedral in shape, although the demonstration of this shape is not as unequivocal 

 as in the case of the Tipula iridescent virus. • 110.000. 



