Further evidence concerning the significance of nuclear inclusions as indicators of a transmissable agent.

Abstract

In 1920 Jackson1 reported the occurrence of what she described as a protozoan infection of the ducts of the salivary glands of guinea pigs. “Round oval, encysted organisms” were found lying in the duct cells of 54 per cent of the guinea pigs examined by this author. Jackson concluded that these structures represented the vegetative cycle of an intracellular protozoan, probably belonging to the group of coccidia.In 1921 Goodpasture and Talbot2 confirmed Jackson's findings. These authors found a striking resemblance between the structures described by Jackson and certain protozoan-like cells found by them in the lung, liver and kidney of a two months old baby. The occurrence of cells of this type in infants had been previously described by several observers, the majority of whom had considered these structures to be protozoan parasites. Goodpasture and Talbot, however, were of the opinion that neither the protozoan-like cells observed in infants, nor the structures in the ducts of the sub-maxillary glands o...