Soldiers from fort riley, kansas ill with spanish influenza at a hospital ward at. Camp funston in 1918, where the north american part of worldwide pandemic began. Viruses are also capable of replication and are much smaller than bacteria and archeans. In their simplest form, a virus consists of its genome surrounded by a protective protein coat, the capsid. The viral genetic information contains the genes required to duplicate the viral genome, manufacture the capsid proteins and assemble the capsid around the copies of the genome. But, viruses lack any of the synthetic machinery to carry this out. Instead they take over the replication, transcription and translation machinery of another cell. Like bacteria, viruses are characterized by their morphology and have one of two forms: non-enveloped or enveloped viruses. Both have the capsid casing surrounding the genome but an enveloped virus has an additional lipid bilayer membrane surrounding the capsid and the genome inside.