Effect of Degree of Encapsulation upon Virulence of Cryptococcus Neoformans. ∗

Summary Thinly encapsulated Cryptococcus neoformans cells were equally as virulent for white Swiss mice as thickly encapsulated cells of the same strain. Yeast cells initially possessing thin capsules promptly developed thick ones upon intracerebral injection into mice, and upon subculture to synthetic capsule medium. Both types of cells produced hydrocephalus to an equal degree. Degree of encapsulation is not a factor in virulence of Cryptococcus neoformans for white Swiss mice.