Thiele J, Kiel H, Adolphs H D
Arch Virol. 1979;62(1):77-82. doi: 10.1007/BF01314906.
The ultrastructure and maturation of avian pox particles is described in the rare case of a naturally infected hawk (Falco cherrug). As in other cells infected by fowlpox virus two types of inclusion bodies are encountered in the cytoplasm: firstly assemblies of fluffy filamentous material apparently giving rise to immature virions. They are thought to present virus factories (inclusion body B). Secondly mature virus particles budded into extensive groupings (Bollinger bodies, inclusion body A) which display a fine structure identical to other strains of fowlpox virus.