VEGETABL33 PHYSIOLOGY AND AGRICULTURE. i. 10 Chemistry of Vegetable Physiology and Agriculture.. Autolysis of Starch. W. BIEDERMANN (Fermentforsch. 19 18 2 200; from C'hem. Zentr. 1918 ii 735. Compare A. 1917 i 62). -Boiled starch solutions aftper some weeks become infected with a bacterium which forms a sulphur-yellow pigment and hydrolysesi. 108 ABSTRACTS OF CHEMICU PAPERS. the starch to dextxose. The bacterium is possibly identical with or a t least closely relatled to Schardinger's BaciElus macerum. The previously recorded autolysis of starch was probably due to infection with this micro-organism. J. E. GREAVES (Soil Sci. 1918 6 163-217).-A r6sum6 of the literature on the subject of nitrogen fixation by Azoto- bacter and Clostridizinz psteum'nnunz. A full bibliography is appended.W. G. Influence of certain Conditions on the Comparative Con- sumption of Dextrose and Lavulose by Sterigmatocystis nigra starting from Sucrose. MARIN MOLLIARD (Conzpt. rend. 1918 167 1043-1046).-Using a culture liquid in which the nitrogen is entirely supplied by one ammonium salt and the ratio nitrogen carboa is 1 IG it is found that the ratio of dextrose to tzvulose consumed is considerably increased by the presence of acid. Similarly the ratio dextrose to lzevulose consumed is in- creased if the ratio nitrogen carbon is diminished to 1 160. In each of these cases the weight of mycelium obtained in a given Lime is also diminished. It is considered that lzvulose plays the principal part in the building up of the tissues. Capacity of Alcohols and Acids to Sustain the Growth of Yeasts and other Common Fungi.TH. BOKORNY (Allg. Brau iEopj. Zeit. 1917 747; from Bied. Zentr. 1918 47 191).-The. author has collected information regarding the behaviour of fungi yeasts and bacteria when cultivated in media containing various alcohols and acids. All acids exert an inhibiting action on fermentatioii when the concentration is increased to a certain limit which differs for each substance. Formic and oxalic acids are specially toxic. Bases are more poisonous than acids towards yeast. H. W. B. Quantitative Estimations of the Enzymic Activity of Living Cells. I. H. Eurmt 0. SVANBERG and S. HEINTZE (Fermentforsciz. 1918 2 194-199 ; from Ohem. Zentr. 1918 ii 746).-At 1 6 O an increase in px from tihe optimum for yeast invertase (5.07 t o 4.67) to 7.7 reduces the activity of the invertase from 0.067 to 0.007.Influence of certain Substances Extracted from Yeast by Alcohol on the Activity of the Yeast Enzymes. EMIL ABDERRALDEN and R. SCHAUMANN (Fementforsch. 1918 2 120-151; from Chem. Zentr. 1918 ii 737-738).-An extract of yeast prepared by boiling with 10% sulphuric acid and subse- quently treating with alcohol exerts an accelerating action on the enzymic cleavage of sucrose knd maltose and on the fermentation of dextrose I~vulose and parbicularly galactose by yeash The fermentation of lactose is not affected. The activity of carb- oxylase is increased. The accelerative action of the extract is observed not only with living yeast but in the cases of dried yeast and pressed yeast juice.Various fractions can be prepared from H. W. B. Azofication. W. G. -. H. W. B.VEGETABLE PHYSIOLOC;Y AXD AGRICULTURE. i. 109 the esti.sct poseasill; tliverse degrees of activating power one of the more powerful beiiig termed +. eutouin." This latter substaiice is prepared by precipitation of the alcoholic extrmt with acetone and is completely free from phosphorus. The author suggests that vitamines may resemble these extracted substances in exert- ing an activating influence on certain enzymic processes in the body. H. W. B. Behaviour of Yeast towards various Carbohydrates in various Concentrations and the Effect of the Addition of Amino-acids on tne Fermentation. ENIL ABDERHALDEN (Fei.iirei?tfol.sc?i. 1916 229; irolu Bied. Zentr. 1918 47 190).- "be extent of alcoholic'fermentation is not affected when the con- centration of the sucrose iii the solution is increased from 10 grams to SO grams per 250 C.C.The loss in weight is greater when alaniiie is added to the sucrose solution. When dextrose is sub- stituted for sucrose the extent of fermentation is found to vary with the concentration of the carbohydrate. When dried yeast is employed a distiiici latent period precedes the onset of ferment- atioii. H. W. B. Phytoehemical Reductions. XIV. Hydrogenation of a Ketone by Yeast. Change of Methylheptenone into the Corresponding Heptenol. C. NEUBERG and A. LEWITE (Biochem. Zeitscb. 1918 91 257--26G).-The change C~~e2:CIE.CH,*CH,*COMe into @~e,:CI-I.C~~,*@H,*GHMe*OH takes place t o the extent of about 10%.The product is sometimes lmorotatory and a t other times dextrorotatory. There is produced a t the same time an equimolecular proportion of acetaldehyde. The ketone appears to compete with this product fornied as an ordinary intermediary product of alcoholic ferrhentation for the available hydrogen. s. €3. s. Excitation oE Ferment Action. I\-OLE'C:ANG M+EICXIARDT and HERMANN APITZSCH (Biochenz. Zeitsch. 1918 90 337-347).-A criticism of certain statements in literature with regard to excita- tion of ferment action with some demonstrations of sources of error in methods of manipulation in experiments on which certain state- ments are founded. These refer more especially to the measurement of catalase action volumetrically to the difficulties of measuring the same amounts of catalase (or blood) and to the errors in the estima- tion of the action of urease due tto t h e neglect of hydrolysis of carbarnide while distilling off the ammouin.s. B. s. The Influence of Aluminium on the Germination of Seeds and the Development of Plants. JULIUS XTOKLASA with J. ~ E B O R W. ZDOBNICKY F. TYMICH 0. HORAK A. N ~ E c and 5. CWAGH (Biochem. Zeitsch. 1918 91 137-223).-This com- munication contains a very det,ailed account of the acbion of aluminium manganese and iron on the germination of seeds and the development of the plants. It indicat'es generally that very VOL. CXVL i fsmall amounts of aluminium salts exert a f avourable infiuence on the geriiiiiiation ol seeds whereas larger amo’unts exer-c a toxlc action. Similar remarks apply t o saim o i rnanganabe.\%‘hen large amounts oi manganese salts exert a toxic action an antagonistic effect can be produced by aluminium salts when the concelitiation of the latker is not too high and the toxic effect of both ions comes into play. h study of the action of these variow salts ,iilell 7,IJed in the nutrient solutio’ns for growing plants indicated thah aluminium is very toxic to xerophytes whereas the hydrolytes and hygrophils show a considerable resistance. As regards the meso- phytes a toxic action could be determined iu the case of iron ions which could be antagonised by aluiiiinium. Aluminium and man- ganese ions iii sufficiently !ow coiicentrations both together or alone produce a iavourable efTect on growth ; higher coneentra- tiom act tosically.There is no antagonistic action as regards toxicity of iron and manganese. The authors deduce from their results a mathematical expression for the growth curves and develop a general theory of the acticn of chemical reagents 011 growth. Measurements were made of the electrical conductivities of the salts employed and comparisons instituted between the intensity oE action of the various ions and the dissociation grade of the salts; a considerable parallelism was found to exist between this physiological in tensity of action and the conductivities of the salt solutions. s. €3. s. Catalase and Oxydase Content of Seeds in Relation to their Dormancy Age vitality and Respiration. WILLIAM CROCKER and GEORGE T. HARRINGTON ( J . ,-2gric. Res. 1918 15 137-1 74).-The concentration or’ solutions of hydrogen peroxide may readily be measured by.determining the volume of oxygen liberated on the addition of an excess of powdered seeds contain- ing plant catalase. Similarly the catalase activity of seeds may be measured by using an excess of hydrogen peroxide but in this case the latter solution must first] be made neutral to phenol- phthalein by the addition of N/lO-sodium hydroxide. The authors have carried out a general investigation as to the coadi- tions affecting catalase and oxydase activity of seeds and find t h a t in certain seeds there is a close correlation between catalase activity and respiratory inteneity but no correlation between these twol factors and the vitality of the seeds or the vigour of the resulting seedlings.They find t h a t general conclusions cannot be drawn as t o the cataIase behaviorir in a11 seeds. but it seems probable that seeds can be separated into several physiological types for each of which more or less general conclusions can be drawn. Catalase activity of seeds seems to agree more closely and generally with phyFiologiea1 behaviour than does oxydase activity. [See further J. SOC Chem. Ind. 1919 February.] Distribution of. the Mineral Elements and Nitrogen in the Etiolated Plant. G ANDRB (Comnpt. rend. 1918 167 1004-1006) .-The author has investigated the proportions of W. G .VEGETABLE PHYSIOLOGY AND AGRICULTURE. i. 1 11 mineral matter and nitrogen which pass during etiolation from the cotyledons into the plantule in seeds germinated in t'he dark in an inert medium.The seeds used were white haricot germinated in sand previously extracted with dcid and calcined. After twenty-five days the stenis being 30-35 cm. in lengt6h the plants were removed and their roots washed. Their cotyledons were separated from the ?tern and roots and weighed separately. and then analysed. The major portion of the calcium remained in !he cotyledons whilst the niagnesiiirn and t o a still greater esterit the potassium had migrated t o the roots and stem. Nearly 75% of the phosphoric acid and nitrogen were transported from the cotvledons to the plantule and the migration of the sulphur was v e ~ similar w. G. Mechanism of Assimilation Processes. K. RCHAUW (Bey. 1918 51 1372-1375).-The conclusions recorded by Willstatter and Stoll (A.1918 i 207) had been drawn previously by the author (Sitzungsber. Ges. Befiid. gesnmt. Natzcrwiss. Mnrhury 1907 158). c. s. Colloidal Properties of Protoplasm. Imbibition in Rela- tion to Growth. FRANCIS E. LLOYD (Tram. Roy. Sue. Canada 191'7-18 11 133-139).-Living protoplasm as such behaves towards acids and alkalis in a manner sufficiently like t h a t of gelatin t o warrant the view t h a t imbibition is a factor in growth. The results in growth are called forth by much lower concentrations of the reagents; this is probably due t o the different nature of the emulsoids involved. J. F. S. Conductivity as a Measure of Permeability. W. J V. OSTERHOUT (1. Biol. Chenz. 1918 36 485-487).-Experiments are described which are designed t o elircidate whether when an electric current passes through a tissue any of the current passes through the protloplasm or all through the intercellular substance.Employ- ing a green marine alga ( U h n ) and a marine flowering plant (Zostern) 'both with cellulose walls it is found t h a t after killing by methods which do not produce irreversible changes in the properties of cellldose the condnctivity rises t o a constant value and is not thereafter affected bv exposure t o reagents which moduce great alterations in the conductivity of living tissues. Noreaver the tem- perature-coefficient of the electric.11 conductivity of livinq tissue differs from that of dead tissue and the effect of placing a tissue in cont'act with a strong calcium chloride solut.ion is not an increase in the conductivity b u t a decrease on account of the diminished conductivity of the protoplasm killed by tke salt more than counter- balancing the increased conductivitv of the intercellalar tissues.The alterations of conductivity observed in livinq tissue are due therefore to chanqes in the protoplasm and not t o chanqes in the non-livinq intercellular snbstar-lce. and as the results obtained by the electrical method are in complete aqreement with those obtained by other methods for measuring permeability such as exosmosis.i. 112 ABSTRACTS OF CBEMICAL PAPERS. diffusion through membranes of living tissue etc. the author draws the conclusion that tho electrical conductivity is a measure of the permeability of the protoplasm of the cell. H. W. B. Effect of Diffusion on the Conductivity of Living Tissue.W. J. V. OSTERHOUT (J. Bid. Chem. 1918 36 489-490).-Elec- trolytes with univalent cations usually produce an increase in the electrical conductivity of living tissues whilst those with bi- or ter- valent cations first diminish and then increase the conductivity. Certain apparent exceptions t o this rule have been noted and theso are now shown to1 be due to' the effect of diffusion. Thus on trans- ferring tissue of .Laminark from sodium chloride to rubidium chloride solution of the same conductivity the molecules of sodium chloride diffuse o a t of the tissue more rapidly than the larger mole cules of rubidium chloride can diffuse inward. Hence there is a temporary deficiency of salt in the tissue and the conductivity accordingly falls.Reverse effects are prociuced on transference into lithium chloride solutions. E. W. B. Method of Measuring the Electrical Conductivity of Living Tissues. W. J. V. OSTERHOUT ( J . Bid. Chem. 1918 36 557-568).-Various types of apparatus are figured and described which permit of the measurement of the electrical conduc- tivity of pieces of living tissue or of intact organisms. Successive measurements do not vary more than 1% from the mean value. H. W. B. The Absorption Curve of the Green Colouring Matter in Living Leaves. A. URSPRUNG (Ber. Dezct. bot. Gcs. 1918 36 73-85).-The absorption curve has been determined by the thermoelectric method for the green pigments in a living leaf of Trudescantiu". A very slight absorption occurs in the green part of the spectrum which increases towards the red and the violet ends reaching a maximum in the violet which is greater than that occurring in the red.Towards the red end of the spectrum the absorption cwve reaches a maximum point between B and C and then falls rapidly towards the ultra-red. H. W. B. Significance "of the Wave-length for StarcMormation fin the Green Leaf]. A. URSPRUNG (Ber. Deut. bot. Ges. 1918 36 86-100. Compare preceding abstract) .-A comparison of the absorption curve with one indicating the extent o€ formation of starch in the green leaf reveals a close parallelism extending from the ulttra-red to the green part; of the spectrum. From this point towards the violet marked divergence is observed ; the absorption increases to a maximum whilst the starch-formation greatly dimin- ishes.It ia probable that the latter phenomenon is occasioned by the action of the ultra-violet light on the stomata which results in the reduction of the supply of carbpn dioxide for photo-synthetic purposes. In a few experiments with leaves containing no stomata,VECIETABLE PHYSIOLOGY AND AGRICULTURE. i. 11 3 the par allelism between absorption and starch-formation could be established as far as the bluish-violet part of the spectrum. H. W. B. Microchemistry of Plants. X. Siliceous Bodies in the Epidermis of Campelia Zanonia I Rich. XI. Crystalline Carotin in the Cup of Narcissus poeticus. HANS MOLISCII (Ber. deut. bot. Ges. 1918 36 277-281 281-282).-Siliceous bodies similar t o those discovered by Mobius ( Wiesner-Festschrif t Vienna 1908 p.81) in the leaves of Cnllisin repens are pre- sent in the epidermis of Campelin Zrr7207zia. They occur in small cells in the leaves and stalks and are insoluble in acids except hydrcrffuoric acid. When the leaf is immersed in phenol solution o r in Millon's reagent the bodies assume a peculiar red hue which renders them very apparent. These two Cornmelime therefore are related not only botanically but also in a pronounced chemical manner. The xed colour in the rim of the cup of Narcissus po2ticU-s is found to be due to the presence of accumulations of carotin crystals in the cells. H. W. B. The Phenol of the Leaves of Coleus amboinicus Lour (C. Carnosus Hassk.). F. WEEHUIZEN (Rec. trail. chin&. 1918 37 355-356 ; Pharm. Weekblad 1918 55 1470-1472).-The essential oil of Coleus amboiiiic~cs contains a phenol which the author has identified as carvacrol.W. G. Presence of Hydrogen Cyanide in a Fern Cystopteris alpina. MARCEL MLRANDE (COP@. rend. 1918 167 695-696).- The fern Cystopteris alpinn Desv. contains in its leaves a cyano- genetic glucoside which under the influence of an enzyme also contained in the plant is hydrolysed and yields hydrogen cyanide and benzaldehyde. The proportion of hydrogen cyanide given by the leaves is lowest in the early part of SBptember (for example OoO1lo/o). C. A. M. Production of Glycine by Isaria densa. MARIN MOLLIARD (Compt. rend. 1918 167 786-788) .-The fungus Isaria densa when cultivated on gelatin decomposes it giving glycine the yield of this amino-acid being equivalent to 33% of the gelatin decorn- posed whereas by acid hydrolysis gelatin only yields 1605% of glycine.Similarly this fungus decomposes fibrin giving 38% of gIycine and also ovalbumin serum-albumin and casein giving on an average 33*6% of glycine. L. REUTTER DE ROSEMONT (Schweiz. Apoth. Zeit. 1918 56 55-56; from Chem. Zentr. 1918 ii 89 736-737) .-The results indicate that certain alkaloids exist pre- formed in poppy juice and are not the products of subsequent fermentation processes. On distillation in a vacuum poppy juice W. G. Sterilised Poppy Juice.gives off fomiic and acetic acids aud after subsequent treatment; with sodium hydroxide ammonia pyrrolicline. and methylpgrrol- idine. By extraction of the tarry residue several bssic mbstances including codeine but nob morphine are obtained.Light petroleum extracts pyrrolidine benzene a yellow ZiquZcZ (C8H3Q4N) awi- cIdo?.ide m. p. 231° chloroform a yellsmish-brown powder (C$&O,N) arid amyl alcohol a solid trlknloid (C2H305N),. The residue is soluble in dilute hydrochloric acid and from the solut.ion sodimii hydroxide precipitates a colourless sirb.rtatice (CHO,N),. Lactic meconic and oxalic acids together with dextrose were also detected in the original juice. El. TV. B. Vegetable and Animal Fats and Waxes. HI. ALBERT 33. WEINHAGEN (Zeitsch. physio7. Ghenz. 1918 103 84-86. Com- pare A. 1918 i 56).-The solid fat isolated from rice bran dces n o t contain any glycerol whilst? the liquid oil contains olnly about 1.7%. H. W. B. Oxydases with Special Reference to their Presence and Function in the Sugar-cane.RAXJI NARAIN (Aqric. J. India 1918 47-64).-Laccases and aldehydsse are found t o Fr? present in the cane but tyrosinase is absent". The author finds t,h;it. the direct guaiacum reaction depends niore on the presence of a peroxide than on t h a t of catechol. As a preservative for oxydases chloroform is far more satisfactory than either ether or toluene. In the cane the lower portions show a greater oxydase activity than the xpper portions and thus tke oxydases are stronzer in that part of the plant where the sugar is stored. Similarlv tke leaf and the adjoining green portion of the c m e are ricliex- in oxydasec than thc stem. The oxydases are not destroyed by boiliiq the extract con- taining them f o r fifteen miniites. nfthouqb they take some time t~ recover their a,ctivity after coolitig.Similwlv a reducing agen b such as hydrogen sulphide only temmrarity inhibits their activitv but does not dest.rog it. perrnanent.ly. The a.ut?hor considers tli-t oxydases are not enzymes in the true s e ~ s c of the word. W. G. Gaseous Products of the Putrid Fermentation and the Odour of Trumes. I. GUARESCHI (Gaxxetta 1915 48 ii 98-106).-The gaseous or highly volatile px-oducts emitted during the putrefaction of truffles are mostly absorbable by soda lime (com- pare! A. 1916 ii 324 562). Those not so absorbed have the odcur of the fresh trufie such odonr being- due t o one o r mol-e gases or volatile compounds which are formed by the putrefactive alteratir,?. of the proteins lout are n o t yet identified. T.R. P. Action of Coal Gas on Plants. IV. Action of Coal Gas on the Root Systems of Trees. Cause of the Action of the Gap,. C. WEX-IMER (Be?.. Bezit. hot. G'es. 1918 36 140-150. Compare 4. 191'7 i 618).-The experiments on the effects produced by pass- ing gas through soil contaix;:: the roots of plants have beenVEGETABLE PHYSIOLOGY AND AGRICULTUEE. i . P 15 esteiided to small trees in pots. It is found that the effect produced is ciependelnt on the seasou of the year in which the experiment is performed; it completely kills the tree in the spring; in autumn the leaves fall off b u t the tree remains alive whilst in winter no pernicious effect is observable. When the soil is replaced by a solution of salts similar toxic efiects are observed.The toxicity appears t o be due t o one or more constit?uents of the gas and not to mere absence of oxygerr. Any treatment of the gas which removes its peculiar odour also abolishes its toxicity a result which seems t o sliow that the toxic agent is that. constituent of the gas which confers on it its characteristic adour. Soil Acidity as Affected by Moisture Conditions of the Soil. S. I). CONNER ( J . Agi-zc. l i e s 1918 15 321-329).-The acidity of acid soils kept under different& conditions of moisture in pots for a year varied with the differellit coiiditions of moisture for a given soil. Soils rich in organic matter showed the greatest acidity alter being kept Tully saturated whilst soils poor in organic matter showed ihe greatest acidity after being kept half-saturated.The potassium nitrate extract from the fully saturated soils contained more soluble ferrous ircii and manganese but less aluminium than the other soils. Thus the measurable acidity of acid soils varies to a large degree under different conditions of moisture and aeration but this variation is due to chemical rather than to physical cfiarrges in the soil. ?V. G . 33. W. B. Determining the Absolute Salt Content of Soils by Means of the Freezing-point Method. GEORGE J. Bou~oucos and M. AT. McCoo~ ( J . Agrzc. Res. 1918 15; 331-336).-The authors find that at a comparatively high content of moisture the iufiuence of the unfree water on the concentration of the soil solu- tion is practically negligible. The f reezing-point method can there fore be used to determine the absolute salt content of soils by bring- ing them to a suitable content of moisture before determining the depression of the freezing point.[For details see J . SOC. Cizem. 1 n d. 191 9 February.] Hydrogen-ion Concentration--Soil Typcs--Common Potato Scab. LOUIS J. GILLESPIE and LmvIs A. HURST (Sod. h'ci. 1918 6 219-235).-The authors find that the electrometric method (compare Giilespie A. 1916 i 303) and the colorimetric method of Clark and Lubs (compare J. U a e f . 1917 2 1 109 191) for determining hydrogen-ion concentration of soiIs give results wliich are in agreement within the limits of experimental error. It is necessary t o add 1 or 2 C.C. of water to each gram of air-dry soil. but this addition of water does n o t seem to be a serious limitation.From an examination of a large number of soils the authors find a close correlation between the hydrogen-ion exponent and the occur- rence of common potato scab. With an exponent below 5.2 scab seldoim appears but with exponents much above this figure the potatoes are generally scabbed. W. G . W. G .i. 116 ABSTRACTS OF CHEMICAL PAPERS. Chlorine index as a Comparative Measure of the Bichness of Soils in Humus. 1,. LAPICQUE and E. BARB^ (Compt. rend. 1919 168 118-121).-The authors find that the amount of an aqueous solution of sodium hypochlorite decomposed in a given time by a given volume of soil varies considerably with the soil taken and that this estimation forms a rough method of placing the soils in the order of their probable richness in humus the volume of chlorine liberated varying directly with the humus content of the soil.W. G . Importance of kIcduici Action in the Soil. SELNAN A. WAKSMAN (Sod SCZ. 1918 6,137-155).-&1oulds have been isolated in large numbers from cultivated and unculbivated soil. By t110 growth of their mycelia changes in the organic and inorganic con- stituents of the soil are brought about but no nitrification or fixa- tion of nitrogen is eff'ected. Not1 much ammonia is produced i n the presence of available carbohydrate as a source of energy as it is absorbed in the formation of mould protein but in the absence of carbuhydrate considerable amounts of ammonia are left in the soil. Carbohydrates are decomposed with the formation of carbon dioxide. Moulds exercise an unfavourable effect on soil fertility in that they compete with green plants for available nitrogen compounds.On the other hand they exercise also a beneficial effect on account of their large production of enzymes and acids which produce further changes in soil constituents favourable to the growth of green plants. [See J. Soc. Clzenz Ind. 1919 February.] Nitrogen Compounds in Rain and Snow. FRANK T. SHUTT and R. L. DORRANCE (Trans. Boy. SOC. Carrzada 1917-1918 [iii] 11 63-72).-A series of analyses of snow and rain which have fallen in o r near Ottawa during the years 1908-1917 is recorded. The analyses deal with the nitrogen compoundfi and are expressed as parts of nitrogen per million as (i) free ammonia (ii) albuminoid ammonia (iii) nitrates and nitrites. The average of these for the ten years is 0.461 nitrogen as free ammonia 0.138 as albuminoid ammonia 0.277 as nitrite and nitrate. This corre- sponds with 6.583 lb. of nitrogen per acre. A further analysis of the results for the various months is also given from which it is shown that snow is decidedly poorer in all forms of nitrogen compounds than rain (compare A. 1915 i 636). Composition of the Waters of the *Inter-Mountain Region. J. E. GREAVES and C. T. HIRST ( J . I d . Eng. Chem. 1918 10 1001-1004).-Analyses of a large number of river waters are recorded the majority of which are used for irrigation purposes. Whilst some of the waters are free from objectionable constituents others although good a t their source were found to contain large quantities of alkali sulphates etc. after flowiiig through a dis- trict rich in soluble salts. The effect of these saline waters on J. H. J. J. F. S. vegetation is discussed. w. P. s. - _.