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High rates of acetylene (C 2 H 2 ) reduction (nitrogenase activity) were observed in woodroom effluent from a neutral sulfite semi-chemical mill under aerobic (up to 644 nmol of C 2 H 4 produced per ml per h) and under anaerobic (up to 135 nmol of C 2 H 4 produced per ml per h) conditions. Pasteurized effluent developed C 2 H 2 reduction activity when incubated under anaerobic but not under aerobic conditions. Activities were increased by addition of 0.5 to 3.0% glucose or xylose. Enrichment and enumeration studies showed that N 2 -fixing Azotobacter and Klebsiella were abundant, and N 2 -fixing Bacillus was present. Of 129 isolates of Klebsiella from pulp mills, lakes, rivers, and drainage and sewage systems, 32% possessed nitrogen-fixing ability.

Summary: Isolates of 26 fungal species from broiler house litter were screened for their ability to metabolize and methylate 2,3,4,6-tetrachlorophenol over a five-day period, by adding the chlorophenol to cultures after mycelial pellets were established on a complete growth medium. Under these conditions, 99 of the 116 isolates tested metabolized the chlorophenol and 68 of these produced 2,3,4,6-tetrachloro-anisole. The proportion of the chlorophenol methylated to the chloroanisole differed widely with the isolate, even within species. The highest methylation was observed with Penicillium corylophilum; certain other isolates, notably of P. brevicompactum, metabolized almost all the chlorophenol without forming the chloroanisole. Progress studies with these species suggested that there is more than one route for the metabolism of 2,3,4,6-tetrachlorophenol. In tests with suspensions of mixed bacterial populations from broiler house litter, the chlorophenol was metabolized but no methylation was detected.

1. O-Acetylated 4-O-methylglucuronoxylans were isolated from sweet chestnut and wych elm, either green or incubated at 48° and 100% relative humidity for 36 weeks. 2. The chlorine–ethanolamine method of delignification resulted in a 50% loss of O-acetyl groups from green wych elm compared with an 18% loss from green sweet chestnut. 3. The acid–chlorite method gave an acceptable loss of O-acetyl groups in three cases, but incubated sweet chestnut showed a 44·6% loss. However, it is believed that this is due to the loss of simple O-acetylated xylose sugars resulting from glycosidic hydrolysis, rather than removal of O-acetyl groups by direct hydrolysis. Assuming that this occurs in a random manner, it is unlikely to have much structural significance. 4. Dimethyl sulphoxide extraction of chestnut holocellulose and elm holocellulose, green and incubated, yielded O-acetyl glucuronoxylans containing 10·2, 3·8, 13·1 and 7·7% O-acetyl groups respectively. 5. The location of these O-acetyl groups was determined by Bouveng's method in which phenyl isocyanate is used as a blocking group.

SUMMARYThe germicidal efficiencies of hot water (140–150° F.) under pressure (method 1), hot water + 2% (w/v) detergent solution (method 2) and hot water + detergent + 200 p.p.m. solution of available chlorine (method 3) were compared at six sites in a bacon factory. Results indicated that sites 1 and 2 (tiled walls) were satisfactorily cleaned by each method. It was therefore considered more economical to clean such surfaces routinely by method 1. However, this method was much less efficient (31 % survival of micro-organisms) on site 3 (wooden surface) than methods 2 (7% survival) and 3 (1% survival). Likewise the remaining sites (debarring machine, black scraper and table) were least efficiently cleaned by method 1. The most satisfactory results were obtained when these surfaces were treated by method 3.Pig carcasses were shown to be contaminated by an improperly cleaned black scraper. Repeated cleaning and sterilizing (method 3) of this equipment reduced the contamination on carcasses from about 70 % to less than 10 %.

The predominant cellulolytic ruminal bacteria isolated from microbial populations supplied diets containing cellulose as an energy source and essentially devoid of amino acids or rapidly fermentable carbohydrates were shown to require branched-chain acid(s) for growth.

A difference in the distribution of microtubules in the peripheral cytoplasm of developing fibres has been observed between normal apple wood and that infected with ‘rubbery wood’ disease. In normal wood, where microtubules are abundant, the fibre wall is lignified, compact in texture and of limited thickness. In rubbery wood, where there are fewer microtubules, lignification is not complete in the fibre wall, which has a coarse, loose texture, and is abnormally thick. The whole stem is highly flexible. The pit membrane, which is unlignified in both normal and rubbery wood, has no microtubules adjacent to the plasmalemma. It is suggested that microtubules are concerned in channelling into the wall substances, such as lignin precursors, which are essential for certain steps in the polymerization of the amorphous component of the wall.

Volatile fatty acids (60% acetic and 40% propionic) were mixed into fresh pine sawdust at 1% and 3% (w./w.) levels. Unsexed day-old broiler chicks were placed on the litter at a density of 0.06 m.2 per bird and reared to 8 weeks of age. There was no significant effect among treatments on the mean body weight, feed conversion efficiency or mortality. The bacterial count was retarded for at least a week. The mold count was slightly decreased at the 3% treatment level for the first 2 weeks. The pH of the litter was reduced significantly (P

The degradation of several alkyl ethers of vanillic acid, of 3-ethoxy-4-hydroxybenzoic acid, and of syringic acid, by the lignin-decomposing fungus Polyporus dichrous included (i) 4-dealkylation (e.g., 3-ethoxy-4-isopropoxybenzoic acid was in part dealkylated to 3-ethoxy-4-hydroxybenzoic acid), (ii) hydroxylation of the 4-alkoxyl groups (e.g., 3-ethoxy-4-isopropoxybenzoic acid was oxidized in part to 2-[4-carboxy-2-ethoxyphenoxy]-propane-1-ol), and (iii) reduction of carboxyl groups (older cultures) (e.g., 3-ethoxy-4-isopropoxybenzoic acid was reduced to 3-ethoxy-4-isopropoxybenzaldehyde and 3-ethoxy-4-isopropoxybenzyl alcohol). Some ethers (e.g., tri- O -methyl gallic acid and glycerol-β-[4-carboxy-2-ethoxyphenyl]-ether) were not affected. The dealkylations and hydroxylations indicate that the fungus has a relatively nonspecific mechanism for oxygenating various 4-alkoxyl groups of alkoxybenzoic acids; no evidence for oxygenation of 3-alkoxyl groups was obtained. Hydroxylation products were generally degraded further, probably via dealkylation. The vanillic acid and 3-ethoxy-4-hydroxybenzoic acid formed by dealkylations were readily metabolized. Although the isopropyl ether of syringic acid was hydroxylated to 2-(4-carboxy-2, 6-dimethoxyphenoxy)-propane-1-ol, neither this compound nor the parent isopropyl ether was dealkylated; syringic acid itself was only slowly and incompletely metabolized. The relationship of these results to lignin degradation is discussed.

Catalpalactone, C15H14O4, a new type of phthalide derivative has been isolated from the wood of Catalpa ovata G.DON and C.bignonioides WALT, and its structure has been determined to be represented by the formula (I).

Some 'spontaneous' tumours of laboratory rodents may be due to carcinogenic constituents of wood shavings used as bedding. The recent finding that the p-0-methyl derivative of sinapaldehyde and 2,6-dimethoxy-1,4-benzoquinone are carcinogenic for the rat may implicate the α, β-unsaturated carbonyl compounds present in wood lignins.

By using stereospecifically double-labelled radioactive mevalonates it was shown that betulaprenols-6 to -9, found in the woody tissue of Betula verrucosa, each contain three biogenetically trans-isoprene residues and that the remaining residues are biogenetically cis. The results obtained with these radioactive mevalonates also indicated that the activity of isopentenyl pyrophosphate isomerase is low relative to the activity of prenyltransferase in this woody tissue. The incorporation of radioactive farnesyl pyrophosphate and radioactive geranylnerol and the lack of incorporation of radioactive geranylgeraniol into betulaprenols-6 to -9 demonstrated that they are formed by the cis-additions of isoprene residues to all-trans-farnesyl pyrophosphate.

A variety of surfaces was tested for self-disinfecting action againstStaph. aureusandEsch. coliat a humidity of 42%. Surfaces which had been treated with disinfectants sometimes reduced the survival when the organisms were applied subsequently in drops of broth, but the reduction was very small unless the surface was able to absorb appreciable amounts of disinfectant and the drop of inoculum spread. When the inoculum was applied dried in cotton dust, only surfaces which evolved formaldehyde showed any activity against the bacteria. These surfaces also reduced the survival of bacteria in liquid inocula.We would like to record our thanks to Dr O. M. Lidwell for much helpful advice.

Poria weirii produced peroxidase in yields amounting to 35% of those obtained from the same weight of horseradish roots. The three isozymes detected were distinct from those of horseradish.

THE heart-wood of western red cedar (Thuja plicata Don.), which possesses a low specific gravity and is very resistant towards decay, has been examined by Anderson and Sherrard1. The steam distillate of this wood furnished an acid, C10H12O2, termed dehydroperillic acid, showing low toxicity, and a very toxic ‘phenol', m.p. 82°, of the same composition. For dehydroperillic acid they suggest the formula (I), but the structure of the compound of m.p. 82° was not elucidated.

Letter concerning a position in horticulture and botany at Utah Agricultural College, copies given to J. C. Blair, J. L. Snyder, and L. H. Bailey.

Summary A performance type of laboratory test has been developed to determine the efficiency of the absorbent surgical materials as a barrier to secondary contamination by pathogenic organisms from the patient's environment. The test was used to determine the efficiency of the currently available surgical dressing materials and showed that under variable clinical conditions, a dressing composed of layers of absorbent B.P.C. gauze would give a more reliable protection than similar thickness of hospital cotton wool or bleached wood pulp. This property of absorbent material has been defined as the volume of fluid which is accommodated by a given thickness of absorbent material at the point of strike-through of fluid to the outer surface of the dressings applied to wounds. The effects of material and clinical variables on the efficiency of the absorbent dressing materials were considered on the basis of the capillary theory of absorption of fluid by the dry porous materials.

INVESTIGATIONS1 on the hydrolysis and water-regaining properties of wood pulp, cotton and cotton linters swelled in sodium hydroxide solutions of varying concentrations showed that, whereas for wood pulps a low constant-limit degree of polymerization and high constant water-regain were reached by swelling in an 8 per cent lye, it was necessary to swell cotton and cotton linters in a 10 per cent solution in order to obtain a similar result. These differences between swollen samples of the two fibres might be due to easier mercerizing, that is, transformation of the cellulose I lattice into the cellulose II lattice, in the case of the wood pulp as compared with the cotton linters.

SOME termites can live on a diet of cellulose filter paper1. This characteristic prompted Hungate2 to question the possibility of N2 fixation in termites by estimating the N balance of growing termite colonies, but he found no net increase in total colony N. Toth3, on the other hand, incubated macerated termites in an N-free organic medium and observed an increase in fixed N in the solution. He used long incubation times, however, and possibly selected for N2-fixing organisms in the medium. We decided to reinvestigate the question of N2 fixation in termites by exploiting the sensitivity of the acetylene reduction assay, a reliable indicator of N2 fixation4,5. Preliminary reports of these results have already been published6,7.

Sixty-seven strains belonging to 47 species of Basidiomycetes were examined for their acid-producing abilities in glucose media, in both the presence and absence of CaCO 3 , in stationary and shake cultures. Some strains were found to produce large quantities of oxalic acid. The oxalic acid-producing strains could be separated into two groups. Strains of one group (mostly brown-rot fungi) were able to produce oxalic acid, regardless of whether CaCO 3 was present in the medium. Strains of the other group (mostly white-rot fungi) were characterized by their ability to produce oxalic acid only when CaCO 3 was added to the medium. With the latter group, shake-culturing was generally more effective than stationary culturing in respect to acid production. In the CaCO 3 -containing media, Schizophyllum commune, Merulius tremellosus , and Porodisculus pendulus were found to produce substantial amounts of L-malic acid as a main metabolic product, along with small quantities of oxalic and other acids in shake cultures. Especially, S. commune and M. tremellosus may be employed as malic acid-producing species.

A follow-up study of a previous epidemiological investigation in a furniture factory concerning allergic contact eczema caused by true teak ( Tectona grandis ) clearly shows that a good educational campaign associated with specific and general prophylactic measures are able to control occupational dermatoses. At the first investigation 20·5% of the workers had allergic contact eczema and/or severe itching whereas only 8·3% suffered from the same complaints on re-examination. The different prophylactic measures previously recommended had been taken. Patch tests with various teak extracts were made on 13 workers sensitized to teak; these showed that lapachol (a derivative of naphthoquinone) is one of the sensitizing agents in teak wood. Furthermore, allergic reactions were obtained in seven of these workers when Jacaranda wood dust containing lapachol was used as the test substance.

RECENT experiments conducted in our laboratories have shown that there is a correlation between the efficiency of organo-mercurial fungicides, used for the preservation of moist groundwood, and the concentration of certain sulphur compounds in the logs from which the groundwood is produced. These sulphur compounds are considered to arise from the reduction of inorganic sulphates, absorbed from salt or brackish water during storage, by halophilic strains of Desulphovibrio desulphuricans. These bacteria have been isolated from the sapwood of logs stored under natural conditions in sea water for a year. Chemical and microbiological studies have been made on samples of pulp, and on logs obtained from a number of Scandinavian groundwood mills after storing for different periods in fresh water, brackish water and sea water. In every case high sulphur contents, expressed as sulphidic and reducible1 sulphur, were found both in pulp samples containing biologically inactive fungicide and in the sapwood of the logs from which they had been made. Conversely, pulps having a high residual content of biologically active fungicide (and consequently a good record of freedom from fungal infection during storage) contained considerably less sulphidic and reducible sulphur, as did the corresponding logs. The latter logs and groundwood pulps came from mills where the wood is stored for 1–2 years in fresh water prior to grinding; the former from mills on or near the coast where the logs are kept in sea water or brackish water for similar periods of time. It has, in fact, been found that after only three months soaking of logs in sea water, mercurial fungicides are de-activated at once on addition to the resultant pulp. It has been shown in the laboratory that the de-activating property progresses farther into the heart of the log with increasing length of immersion.

SOME years ago Suolahti1 found that volatile substances evaporating from wood of various trees strongly promoted the growth of several wood-destroying Hymenomycetes. In particular, the development of aerial mycelium was favoured. The effect seemed to be correlated with the presence of oleic acid and other unsaturated fatty acids in the wood. The active substance or substances could not be identified.

Proceedings: Zearalenone in the diet, podophyllotoxin in the wood shavings bedding, are likely to affect the incidence of "spontaneous" tumours among laboratory animals

WEAVER1 has shown that autumnal application of gibberellin prolongs dormancy of Vitis vinifera shoots in the following spring. We2 recently reported that application of gibberellic acid in late summer and autumn delayed leaf-fall of several woody species; further observations on these plants this spring have shown that in many of them dormancy was prolonged. Thus this unexpected response to gibberellins may not be uncommon.

MANY workers have identified the hexuronic acid components of pectins, gums and mucilages1. However, the uronic acid components of wood hemicelluloses have proved difficult to identify. O'Dwyer2 and Yaramori and Tachi3 have shown that glucuronic acid is present in the hemicelluloses of beech wood and of elm wood respectively. O'Dwyer4,5 has obtained, from oak wood, an aldobiuronic acid containing one methoxyl group per uronic acid residue. Also, Sands and Gary6 have obtained an aldobiuronic acid from mesquite wood hemicellulose: they demonstrated that the aldobiuronic acid contained a methoxyl group and, because of the difficulty encountered in the identification of the uronic acid (viewed in the light of the experience of Anderson and Otis7), suggested that the methoxyl group was attached directly to the uronic acid residue.

Thirteen cestodes, which I am describing as Andrya neotomae n. sp., were collected on June 23, 1941, from the small intestine of a male Neotoma fuscipes caught at the Hastings Natural History Reservation, Monterey Co., California. The worms were fixed in formalin and stained with Ranvier's picro-carmine, Grenacher's borax carmine, or Ehrlich's haematoxylin. The author is indebted to Dr. Harold Kirby for helpful suggestions in the preparation of this paper, and to Dr. Jean M. Linsdale for lending the material from which this study was made.