XI. VIRUSES AND NUCLEIC ACIDS 



109 



virus by Pfankuch (153) did not indicate a concentration of the com- 

 paratively dense nucleic acid in any particular part of the virus particle, 

 and it was suggested that the virus may consist of either a long- 

 Table 6. 

 Chemical Composition of Viruses. 

 After Beard, J. W. : J. Imm., Vol. 58, 49, 1943. 



Whole complex 



N 





Lipid 



Nonlipid 



o 





CJ 



Nucleic 

 Acid 



^ < 



Q I K 



Broth Bacterio- 

 phage 



Synthetic Medium 

 Bacteriophage • • • • 



Vaccinia 



Papilloma 



42.0 



42.3 



13.5 



4.84 



13.3 5.22 



33.7! 15.3 0.57 

 49.6 15.0 0.94 



Equine Encephalo- 

 myelitis (Eastern 



St.) • 



Influenza A (PRS 

 Strain) 



Influenza B (Lee 

 Strain] 



Swine Influenza' 



Broth Medium 

 Bacterium 



Synthetic Medium 

 Bacterium 



Normal Chick Em- 

 bryo Component- • 



62.2 

 53.2 



52.7 



51.4 



49.1 

 49.0 

 55.3 



7.7 



10.0 



9.7 

 9.0 



13.2 



13.2 



9.5 



2.2 



0.97 



0.94 

 0.87 



13.6 



11.7 

 2.8 

 6.5 



4.0 



12.5 



13.1 

 10.0 







2.6 97.4 50.6 



1.8 98.2 52.4 



1.4 2.2,94.0 89.0 



98.5 90.0 



13.89.6 



2.721 12-5 



2.66 

 3.2 



11.6 



7.0 



7.0 



3.7 

 5.7 











53.0,49.1 

 77.5 65.0 

 76.4 63.6 



13.1 



11.2 

 2.8 



7.2 

 7.3 

 9.4 



40.3 



44.6 

 5.6 

 8.7 



1.5 



1.2 



6.6 

 1.3 



6.5 6.9 



4.4 

 7 



7 



7 



19.1 

 20.9 



10.6 



All values are per cent dry weight of the whole complex. 



protein chain with nucleic acid side groups, or a regular arrangement 

 of alternate nucleic acid and protein residues. The fact that tobacco- 

 mosaic virus is readily decomposed into smaller fragments also supports 

 the view that nucleic acids are distributed in a homogeneous dissipa- 

 tion in the virus particles. 



According to Schramm (154), tobacco-mosaic virus particles dissociate 

 in alkaline solutions into two components, one of them free of nucleic 

 acid, but having the same molecular weight as the other contaning 

 nucleic acid. Readjustment of the solutions containing either one of 

 them to pH 5, yielded particles practically indistinguishable from the 



