Fig. 12. A nuclear poly- 

 hedron from the silkworm, 

 Bombyx mori, after treat- 

 ment with weak sodium 

 carbonate. Note that the 

 costal has dissolved and 

 liberated many virus rods, 

 some with and some with- 

 out their capsules. (Magni- 

 fication: X 17,000.) 



Fig. 13.^Cytoplasmic poly- 

 hedra from P. meticulosa after 

 treatment with weak sodium 

 carbonate. Note sponge like 

 residue and absence of virus 

 particles (compare Figs. 1 1 and 

 12). (Magnification: X 14,000.) 



Fig. 14. Three granulosis 

 particles from a larva of Pieris 

 brassicae, frozen-dried. Note 

 the crystalline shape (compare 

 Fig. 22). (Magnification: x 

 15,000.) 



(Fig. 14 electron micro- 

 graph by R. C. Williams.) 



