Commercially produced red wines were adjusted to pH 3.0, 3.2, 3.5, 3.7, or 4.0 and examined during and after malolactic fermentation for growth of lactic acid bacteria and changes in the concentrations of carbohydrates, organic acids, amino acids, and acetaldehyde. With one exception, Leuconostoc oenos conducted the malolactic fermentation in all wines and was the only species to occur in wines at pH below 3.5. Malolactic fermentation by L. oenos was accompanied by degradation of malic, citric, and fumaric acids and production of lactic and acetic acids. The concentrations of arginine, histidine, and acetaldehyde also decreased at this stage, but the behavior of hexose and pentose sugars was complicated by other factors. Pediococcus parvulus conducted the malolactic fermentation in one wine containing 72 mg of total sulfur dioxide per liter. Fumaric and citric acids were not degraded during this malolactic fermentation, but hexose sugars were metabolized. P. parvulus and species of Lactobacillus grew after malolactic fermentation in wines with pH adjusted above 3.5. This growth was accompanied by the utilization of wine sugars and production of lactic and acetic acids.

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Ontogenetic development of chromoplasts from the coloured outer perianth segments of the flower of Strelitzia reginae was examined with an electron microscope. The plastids evolved through five stages, namely, colourless leucoplasts, chloroplasts, pale yellow, deep yellow and orange chromoplasts. The relationship between plastid ultrastructure and carotenoid composition is discussed. The development of fibrils from osmiophilic globules is shown to occur in chromoplasts which contained only small amounts of chlorophyll at an early stage of development. Regular lattices of globular subunits were found which showed a hexagonal or rhomboidal pattern and which are probably protein in nature. The sudden disappearance of these crystals just before fibrils form, and the complete absence of starch from all stages of plastid development, suggests that these crystals are a form of energy storage.

Fruit of the tropical vine Monstera deliciosa undergo a pronounced climacteric during ripening with the concomitant large increase in ethylene production. The ripe fruit contains 19.1% soluble solids and 0.41% oxalic acid; the juice is considered safe for human consumption with respect to the levels of saponin, hydrocyanic acid and oxalic acid.

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