R. maximum is a shrub with relatively large, oblanceolate to ovate, entire, evergreen sclerophyllous leaves which persist 3-8 yrs. Persistence of these leaves permits following changes in their characteristics with time by measuring leaves through the series of annual whorls on a twig. Sets of 10 lower and 10 upper twigs were collected from each study area; and leaf blade length and width, petiole length, live and dry blade and petiole weights, and blade thickness were measured for all leaves. Ten unbranched twigs provide a sample of 42-48 leaves on the average in each more recent annual whorl for the forest communities, more than 50 leaves for the chestnut oak heath and heath bald communities. Blade areas of 50 second-year leaves were measured with a dot grid for each set of twigs. Leaves collected in late summer (late Aug., early Sept.) were used to minimize effects on the curves of immaturity of current leaves. Twig samples were taken also in early and mid summer. Net production by R. maximum was analyzed as described by Whittaker (1961), with additional leaf data, in 3 study areas. Chlorophyll content was determined for discs of fresh leaves by spectrophotometric measurement. Leaf samples were transported in an ice chest from the Great Smoky Mountains to the University of Tennessee, and from Harriman State Park, N. Y., to Brooklyn College. Leaf discs were ground in 80% acetone rendered mildly alkaline with NH40H in cooled pyrex tissue homogenizers; for R. maximum 5 discs 12.7 mm in diameter were extracted into 25 ml of acetone solution. The 5 discs were taken from different positions on 5 leaves of the same age on a given twig, and analyses for each age were run on 5 twigs. A Beckman DU manual spectrophotometer was used at the Univ. of Tenn.; at Brooklyn College 3 Beckman DU and one DK recording instruments were checked against each other. Readings were taken at a number of wave lengths (630, 642.5, 645, 649, 652, 660, 663, 665 mrn ) needed for substitution into formulas for chlorophyll determination in acetone. Results suggest points of caution on chlorophyll determination (cf. Smith & Benitez 1955, SestAk 1959): (1) Chlorophyll determinations for single discs or leaves are subject to rather wide dispersions. Use of discs from several leaves for each determination reduces these dispersions, but the replications for sets of 5 twigs gave coefficients of variation for chlorophyll content ranging usually between 6% and 10% but in some samples up to 20-25%. (2) Comparison of results from different spectrophotometers at Brooklyn College emphasized the significant errors, especially in determination of chlorophyll a and b content, which result from small departures from adjustment (cf. Vernon 1960). (3) The various formulas for chlorophyll determination give different results; the Arnon (1949) formulas are used here. For the determinations in Tenn., values computed from other formulas differed from these on the average as followsMackinney (1941) x 0.96, Weybrew (1957) x 0.81, Richards & Thompson (1952) x 1.06, Sweeney & Martin (1958) x 0.89, Vernon (1960) x 0.91. (4) Chlorophyll a and b ratios ranged even more widely with the different formulas to some patently impossible values. The authors have not felt that these a/b ratios, for chlorophyll mixtures in acetone, merit publication (cf. Van Norman 1957). (5) Carotenoid determinations also varied for the different formulas, and results are not published here. Chlorophyll was regularly determined only for leaf blades, although significant amounts occur elsewhere in plants (Bray 1960).