Ether-soluble "oils" of specific gravity > 1 were produced extracellularly in yields of over 16 gm./liter fermentation mixture by strains of Ustilago zeae growing in shaken flasks on medium containing cerelose, urea, and sugar beet molasses. The bulk of the oily material was shown to be a glycoside of mannose and erythritol, and in addition, itaconic acid and dianthrone were shown to be present. Yields of itaconic acid as determined by a bromine–iodine method at pH 1.2 (Friedkin) reached values of over 15 gm./liter but such values were considerably higher than those indicated by quantitative isolation of this acid. One hundred and eighty isolates of Ustilago were grown on medium with and without calcium carbonate and some 45 isolates produced extracellular oily material, 98 produced ustilagic acid, and 50 produced both crystals and oil. Ether-soluble substances from freeze-dried fermentation mixtures of different isolates ranged from 1 to 12 gm./liter, while methanol-soluble substances from ether-extracted freeze-dried fermentation mixtures ranged from 1 to 45 gm./liter.

for preparation of lignified coleoptiles and the suggestion that larger quantities of eugenol lignin could be produced on potato parenchyma. He is grateful to Mrs M. Szilagyi for technical assistance. The microanalyses were carried out by the Australian Microanalytical Service.

No abstract

Thin sections of embryonic avian bone decalcify during preparation for electron microscopy, creating a false impression of mineral distribution. The results of the experiments reported herein show that viscous embedding materials do not penetrate compact formed bone, and so, in thin sections, the calcium apatite crystals may be leeched out by water, both in the collecting trough and in aqueous solutions of stains used to enhance tissue electron opacity. To prevent decalcification, a simple technique is described in which the aqueous fluids that come in contact with thin sections are saturated with respect to calcium and phosphate ions, thereby preventing solution of the bone mineral. The theoretical basis of this technique is briefly discussed.

Griseofulvin [7chloro-4:6:2'-trimethoxy-6'methylgris-2'-en-3:4'-dione (I:R, R', Me)], a product of Penicillium gri8eofulvum Dierckx, was first isolated by Oxford, Raistrick & Simonart (1939): its structure was first established by Grove, Ismay, MacMillan, Mulholland & Rogers (1951). This compound has fungistatic activity and was reported to control experimental ringworm in guinea pigs (Gentles, 1958) and in calves (Lauder & O'Sullivan, 1958) when administered orally.