In 1932 the senior author reported on an ecological survey in stands of Pinus virginiana in Munroe County, Indiana, viz. the Pennington grove near Weimer Lake, two miles sw. of Bloomington, on highway 45, and the Christie-Freeman groves, four miles nw. of Ellettsville. At the time of the 1931 survey very little ground cover had developed in either of these groves. The repesent study considered only the Pennington grove. This stand has seen no decided cultural modifications since the 1931 survey. Periodic surveys were made in the stand by various groups of ecology students of Butler University. These surveys showed a definite trend in succession which now definitely forecasts replacement of the 100 per cent coverage of crown by Pinus virginiana. The invaders consist of a large number of broadleaved species. The forst floor, which in 1931 was almost bare, is today extensively covered by herbs and the seedlings of tree and shrub species. The authors made a survey in July and September of 1947 to define in quantitative terms the trends in succession in the Pennington grove.