Fig. 5. Tissue culture preparation of influenza virus. A prime. Cells have been removed 

 and residual virus is shown. Segmenting forms are shown in mid-left field. (From Murphy 

 and Bang, 1952) (Magnification: X 7500). 



Fig. 6. Section of membrane infected with recently adapted strain of influenza A 

 virus. Long filaments project into the fluid. (From Bang and Isaacs, 1956) (Magnification: 

 X 14,200). 



Fig. 7. Section through 2-day-old infection with swine influenza virus. (From Murphy 

 and Bang, 1952) (Magnification: X 15,000). 



