A statistical analysis of the assemblages of opal phytoliths in two Victorian soils of different origin, occurring approximately 90 miles apart and supporting generally different plant communities, reveals that some shape types of the phytoliths are common to both soils, while significant differences occur in the amount and nature of other shape types. The general conclusion is that the phytoliths in soil from basaltic tuff on the summit of Mt. Gellibrand in the Western District derive from the local plant population; those in alluvial clay soil developed under swampy conditions at Dalmore, Koo-wee-rup Swamp, derive largely from the local swamp vegetation, with the possibility of the introduction of certain shape types from different plants supported on the southern Dandenong Ranges 18 miles to the north, and on intervening areas. Transportation into the swamp lands would have been effected by the watercourses flowing in from the north, once the phytoliths had been released from plants and shed into the soils near the watercourses. It is doubtful whether any significant proportion of the phytoliths was wind-borne into either of the soils examined.