Fig. 23. Virus particles from \vhich 

 the protein has been removed in 

 some places (after Schramm. Schu- 

 macher and Zilli^). 



# =. >* 



Fic.. 24. Tobacco mosaic virus showing nucleic acid 

 threads, rod-shaped particles and discs of protein whh 

 liolcs ill ihc middle (after Schramm. Schumacher and 



Zillig). 



