198 



THE PHYSICS OF VIRUSES 



have been rei)resented as a pattern of aromatic amino acids, 

 which Butenandt has shown to })e oriented in the virus. The 

 pattern continues throughout the whole volume, and so has been 



NDV 



Water 



Nucleic 

 Acid 



Protein 

 Lipid 



Fig. 8.5. Newcastle disease virus. This has an outer layer of lipid, through 

 which project the hemagglutinins. The structure is simple and must be 

 capable of unrolling in the infectious state. It is probably heavily hydrated. 



shown on the end. A small layer of hydration has been indicated, 

 perhaps rather overconfidently, as bound on the surface. 



The third virus pictured is T-1 bacteriophage. Radiation 

 studies show this to have a complex morphology, and an attempt 

 to represent it schematically has been made. The nucleic acid 

 is shown as made up of eight units, all attached to protein. The 



