Fig. 1. Larvae of Aglais urticae, the small 

 tortoise-shell butterfly, killed by a nuclear 

 polyhidrosis. Note the characteristic position of 

 the dead caterpillars. (Magnification: x 1.) 



Fig. 3. Blood cells from a 

 larva of Sphinx ligustri in- 

 fected with a nuclear poly- 

 kedrosis. Note the large 

 numbers of polyhedra. (Mag- 

 nification: x 530.) 



Fig. 2. Thin section of a blood cell from 

 a larva of Tipula paludosa, the crane fly, 

 infected with its nuclear polyhedrosis. Note 

 the greatly enlarged nucleus with its double 

 membrane and three polyhedra containing 

 the rod-shaped virus particles. (Magnifica- 

 tion: x 17,000.) 



Fig. 4. Thin section of two nuclear polyhedra from 

 Euvanessa antiopa. Note the haphazard arrangement of 



the occluded virus rods. (Magnification: X 30,000.) 



