In attempting to survey the factors associated with the size of the standing crop of natural vegetation types, a more detailed study was made, in the late summer (September, 1953) of the soil relations of stands of Phragmites communes under various habitat conditions. The basis of the estimates differed somewhat from that used in the previous paper. Less attention was paid to the amount of average cover and more to the attempt to estimate maximal performance in each site. It was found necessary where performance was poor to use the size of isolated shoots as the criterion and under these circumstances the sample quadrats on more favourable sites were taken in representative clumps of the denser stands. As a result the weight of shoot per unit area of soil would give local maximum crop weights rather than the average cover as mean standing crop. In many cases, samples were taken where Phragmites was not completely dominant, and in at least two instances, the Rannoch Moor and Kinrara 2 sites, the shoots were scattered and of a vestigial nature, so that only one would have been found in a quadrat of 625 sq. cm., the size used. In the denser stands examined the quadrats usually contained between 7 and 9 shoots fairly constantly.