PLATE XVI 

(Markham, Smith, and Wyckoff) 
INDIVIDUAL CRYSTALS OF TOBACCO NECROSIS VIRUS 
PHOTOGRAPHED ON THE ELECTRON MICROSCOPE 
Note the regular arrangement of the virus molecules on the crystal face. 

(Markham, Matthews, and Smitn) 
How TO INOCULATE A RABBIT WITH A PLANT VIRUS 
TO PRODUCE THE ANTISERUM 
The vein to be used is outlined in Indian ink. The injection is being done by a 
left-handed person. 
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