Electron microscopic studies on lumpy skin disease virus type "Neethling".

This technique has also been used extensively in studies on the structure of pox viruses. Horne & Wildy (1963) have reviewed the results obtained by various investigators working with this group of viruses. The more recently published findings of Buttner, Giese, Muller & Peters (1964) and Peters, Muller & Buttner (1964) suggest that the viruses of the pox group can be divided into the following two distinct morphological groups. (i) Vaccinia-variola virus group; (ii) Ecthyma contagiosum virus (Orf, contagious pustular dermatitis) of sheep; stomatitis papulosa virus of cattle and paravaccinia (milkers nodule) virus, for which the name paravaccinia group has been proposed. Compared with members of the vaccinia-variola group of which the virus particles are brick-shaped with an axis ratio of 1 · 3, the virus particles of members of the paravaccinia group are smaller and more ovoid, have more pronounced surface filaments, a fainter double element and an axis ratio of 1 · 7.