The Polya urn scheme is extended by allowing a continuum of colors. For the extended scheme, the distribution of colors after $n$ draws is shown to converge as $n \rightarrow \infty$ to a limiting discrete distribution $\mu^\ast$. The distribution of $\mu^\ast$ is shown to be one introduced by Ferguson and, given $\mu^\ast$, the colors drawn from the urn are shown to be independent with distribution $\mu^\ast$.
"Ferguson Distributions Via Polya Urn Schemes." Ann. Statist. 1 (2) 353 - 355, March, 1973. https://doi.org/10.1214/aos/1176342372