“…The natural environment of C. neoformans is not known; pathogenic strains have been isolated from soil (Emmons, 1951) and from pigeon nests and droppings (Emmons, 1955). Spontaneous infections occur in animals, but seem to be uncommon (literature: Skulski and Symmers, 1954); the only animal infection so far reported in Britain was in a pet ferret (Skulski and Symmers, 1954), although Carter and Young (1950) Fisher (1950, Case 2), a case described by Gandy (1950), two cases illustrated by Littman and Zimmerman (1956), a case described by Lepow et al (1957), that reported by Leithold et al (1957), and a further case which Littman and Zimmerman (1956) mentioned and which they said would be reported by Heller, McLean, Campbell, and Jones (1957). Torulosis has repeatedly been observed in cases of Hodgkin's disease and other malignant diseases arising in the lymphoreticular system; Zimmerman and Rappaport (1954) reviewed this association, and from their study of the cases filed in the Armed Forces Institute of Pathology at Washington D.C. presented evidence which strongly supports the belief that the mycotic infection in such cases is a complication of the primary disease of the lymphoreticular system and not its cause.…”