bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE GERMINATION OF POA SPP.
Authors: NELSON ALEXANDER 
Published: February 2008

Summary.The paper in its first part deals with the germination response, in the laboratory, of four species of Poa to variations of temperature, light and the nature of the moisture supply. The second portion deals with the same response of P. compressa to solutions of various salts used as moisture supply. The third part deals with the germination of P. compressa in the soil when all the above factors were varied. In the laboratory, alternation of temperature proved to be, generally, the most, efficient stimulant followed by light and a solution of potassium nitrate as moisture supply. P. compressa proved to be more sensitive than any of the other species considered, P. pratensis and P. nemoralis rather less so, while P. trivialis was almost insensible to variations of the conditions. In the soil. excess of light (sunlight) proved to be depressant. Some salts. e.g potassium nitrate, sodium nitrate, ammonium nitrate, etc., proved to be stimulating in solution culture, while salts of lead were depressant. As a general statement these salts, found to be stimulating in solution culture. proved to be more depressant in soil than those found depressant in the solution. Lead salts in the soil produced broader, deeper coloured leafage than the controls. Nitrites had a striking physical effect in preventing the drying up of the soil.
The Transmission Of “Mosaic” Disease In Hops By Means Of Grafting
Authors: THRUPP T. C. 
Published: February 2008

Summary.

In these experiments. where susceptible scions have been grafted on to “mosaic” stock, all developed “mosaic” symptoms with one exception. Circumstances were not favourable in this particular case and it. should be regarded as giving indecisive not negative evidence. From the other cases there is satisfactory proof that, the supposed “virus” can be transmitted up the growing bine.
With the “carrier” experiments, all the known susceptible sciens, which were grafted on to the “carrier” (M 45) stock, exhibited “mosaic” symptoms. The variety M 45 must, therefore. be regarded as capable of transmitting the disease to susceptible hops, and as being a “carrier.”
There is no evidence that the process of grafting can of itself in any way induce “mosaic” symptoms to pear in healthy susceptible hops, or in the “carrier” M 45
IMMUNITY OF POTATO VARIETIES FROM ATTACK BY THE WART DISEASE FUNGUS, SYNCHYTRIUM ENDOB IOTICUM (SCHILB.) PERC.
Authors: ROACH. W. A. 
Published: February 2008

Summary.It is known that grafting together portions of two different plants is sometimes followed by changes in their chemical contents owing to permeation of each by substances formed in the other.The present investigation is an attempt to determine by grafting together pieces of immune and susceptible plants whether the cause of immunity from wart disease of potatoes is carried by chemical compounds which can traverse unchanged a graft fusion layer or by those which are unable so to do.For this purpose all the eight possible types of plants have been built up by grafting together root, shoot and tuber systems from either immune or susceptible plants.In none of the experiments was the reaction of the tubers towards wart disease seen to be changed.The deduction is therefore drawn that the cause of the immunity is not carried by any compound which is able to traverse the plant.In this way the problem is considerably narrowed down, for it is now possible to eliminate many lines of attack as unlikely to be fruitful.The suggestion is put forward that the examination of the proteins from immune and susceptible varieties by immunochemical methods is the most hopeful future line of attack.
THE DECOMPOSITION OF NAPHTHALENE IN THE SOIL AND THE EFFECT UPON ITS INSECTICIDAL ACTION
Authors: TATTERSFIELD F. 
Published: February 2008

Summary.

The insecticidal action of naphthalene and its duration in the soil have been studied.
When naphthalene is incorporated thoroughly with soil it shows a fairly potent toxic action on wireworms; uneven distribution lessens its efficiency as, owing to its low vapour pressure and consequent slow spread, it produces only a small zone of toxic action.
Naphthalene is slow in toxic action, taking three or four days to kill wireworms, as a consequence of which and of its repellent action to insects, if the chemical be unevenly distributed in the soil insects tend to move away from positions where toxic action would be exerted.
The persistence of the toxic action depends upon the soil type. In soils rich in organic matter, toxicity disappears more rapidly than in soils less rich in organic matter. Toxicity persists longer in sterile soils and in sand than in unsterilised soils, and in dry than in moist soils.
The rate of disappearance of naphthalene from soil has been determined. It depends very little upon volatilisation but almost entirely upon some factor inherent in the soil, which is more active in soils rich in organic matter than those poor in organic matter, and in unsterilised soils than in sterile soils.
Second and third doses of naphthalene added to the soil, when the first has disappeared, are decomposed more rapidly than the first dose.
The bacterial numbers of the soil are at first decreased by the addition of naphthalene, but there is a rapid rise during the period when acceleration in the rate of decomposition of the naphthalene is taking place. All the evidence indicates that the loss of naphthalene from the soil is mainly due to bacterial decomposition.
Experiments in sealed bottles indicate that the opening of the bottle and mixing of the sample expedite the disappearance of naphthalene from the soil.
The toxicity of α‐chlornaphthalene persists for a longer time in soils than naphthalene, and is decomposed at a slower rate. An admixture of naphthalene appears to induce a more rapid disappearance of the toxicity of the chlornaphthalene. α‐Chlornaphthalene is more toxic to plants than naphthalene.
Methods of estimating naphthalene are described. They depend on formation of naphthalene picrate. Picric acid can be more readily titrated by alkali in orange and yellow coloured light than in white light.
It was noted in several tests that the prolonged aeration of soils which had been heated and allowed to cool gave rise to formaldehyde.
THE TOXICITY OP CERTAIN SULPHUR COMPOUNDS TO SYNCHYTRIUM ENDOBIOTICUM, THE FUNGUS CAUSING WART DISEASE OF POTATOES
Authors: EOACH W. A. , GLYNNE MAEY D. 
Published: February 2008

Summary.The toxieities towards the winter sporangia of Synchytrium endobioticum of certain of the simpler sulphur compounds which are at all likely to be formed when sulphur is added to soil were tested and compared with that of sulphuric acid.Sulphuric (H2SO4), sulphurous (H2SO3), dithionic (H2S2O6), trithionic (H2S3O6), tetrathionic (H2S4O6), and pentathionic (H2S5O6) acids were toxic and this toxicity was of the same order in each case at the same hydrogen ion concentration. Their neutral salts were non‐toxic. These facts suggest that the toxicities of these acids are mainly due to their hydrogen ion concentrations.Acidified solutions of sodium thiosulphate Na2S2O3, sodium hydrosulphite Na2S2O4 and sodium formaldehyde sulphoxylate were about ten times as toxic as sulphuric acid.Evidence is brought forward which suggests that the toxicity of these acidified solutions, in excess of that accounted for by the hydrogen ion concentration, is due to the thiosulphuric acid present in each of them. In view of the experimental difficulties due to the instability of some of the compounds and the length of time taken by them to exert their toxic action on the fungus investigated, this conclusion must be regarded as tentative.Of the other compounds tested sodium hydroxide was found to be a little more toxic than sulphuric acid and persulphuric acid about ten times as toxic; hydrogen peroxide, calcium polysulphide and sulphuretted hydrogen were only slightly toxic.
THE MOSAIC DISEASE OF THE HOP; GRAFTING EXPERIMENTS, I
Authors: SALMON E. S. , WARE W. M. 
Published: February 2008

Summary.

Certain hop plants, which were grafted in 1926 with scions either (a) of plants affected with the mosaic disease, or (b) of the seedling variety M 45 (previously proved to be a “carrier”), produced in 1927 shoots affected with mosaic disease.
From the evidence available, it would appear that the virus of mosaic disease can travel down a grafted stem and infect the rootstock.
It would appear, further, that mere contact of a virus‐carrying scion with the stock (with no growth of the former taking place) is sufficient to cause the infection of the rootstock.
When scions of the commercial variety Fuggles were grafted on a hop plant severely affected with the mosaic disease they remained healthy and completed their full seasonal development.
ENGLISH‐GROWN PYRETHRUM AS AN INSECTICIDE. I
Authors: FRYER J. C. F. , TATTERSFIELD F. , GIMINGHAM C. T. 
Published: February 2008

Summary.

The toxicity to Aphis rumicis L. and to certain caterpillars of spray fluids prepared from samples of pyrethrum (Chrysanthemum cinerariaefolium) grown in England from Swiss and Japanese seed have been quantitatively determined.
Pyrethrum flowers, grown in six different localities, showed only slight differences, and, for practical purposes, all the samples had approximately the same toxicity. They did not differ in this respect significantly from a sample grown on the continent.
The toxicities of extracts of equal weights of pyrethrum flowers tested at different stages of development differed very little.
Artificial drying of the flowers had no significant effect on the toxic properties.
The flowers were about ten times as toxic as the stalks, weight for weight.
Prolonged exposure of pyrethrum to wet conditions led to some loss of toxicity, but. contrary to the usual opinion, if stored in a reasonable manner, it remained for long periods without deterioration.
Caterpillars of different species showed marked differences in susceptibility to the action of pyrethrum.
The biological method employed has proved suitable for evaluating samples of pyrethtum.
STUDIES ON OSCINELLA FRIT LINN: OBSERVATIONS ON INFESTATION AND YIELD, SUSCEPTIBILITY TO INFESTATION, RECOVERY POWER, THE INFLUENCE OF VARIETY ON THE RATE OF GROWTH OF THE PRIMARY SHOOT OF THE OAT AND THE REACTION TO MANURIAL TREATMENT
Authors: CUNLIFFE NORMAN 
Published: February 2008

Summary.The notes collected in the present publication are each concerned with some aspect of the problem of production of varieties of oat plants resistant to the attack of the frit fly.The quality of a variety may compensate for comparatively heavy infestation.Data are recorded confirming previous experimentation relating to the susceptibility of the oat shoot to infestation, emphasising its limitation to the early leaf stages.Experimentation concerned with recovery power after injury showed that different varieties of oats react very differently and indicated the importance of the primary shoot in relation to yield. A few field data are recorded to support this inference.With common English varieties of oats the influence of variety on the rate of growth of the primary shoot was practically negligible, and therefore observed differences between varieties in extents of infestation of primary shoots cannot be ascribed to variations in rates of growth of primary shoots. The time of tillering did not depart markedly from the mean, but it was not correlated with time of shoot production, so that correlation between extent of infestation of shoot and of grain cannot be expected.Excess of nitrogenous manure failed to influence the extent of shoot infestation but effected a reduction in the extent of grain infestation during a season when the extent of the attack of the fly was below normal.
SPRAIN OR INTERNAL RUST SPOT OF POTATO
Authors: BURR SYDNEY 
Published: February 2008

Summary.

In the present investigation necrosis of the tubers was found to be due to two distinct diseases: (1) Sprain or Internal Rust Spot, and (2) a disease hitherto unrecorded, which has been named Corky Bacteriosis of the xylem. The former is much the more important and accounts for 98 per cent. of the tissue destruction.
In Sprain the tissue attacked is the parenchyma both within and without the vascular ring. The lesions vary greatly in form and may consist of spots, arcs, streaks or irregular blotches. The larger lesions are generally hollow in the centre.
The histological structure of the lesions of Sprain varies slightly according to whether these occur in the starch‐packed cortical tissue or in the pith where the cells are less densely filled with starch, but in either case, is characteristic. A feature of the spots is that they are more or less completely invested with a zone of cork the inner layers of which are suberised.
The soil on which. Sprain occurs in a virulent form is a light sandy loam deficient in organic matter and one on which potatoes scab severely.
The disease is apparently slight when the crop is lifted but develops rapidly and continuously during storage.
Infection of the crop arises mainly from contaminated soil and not from affected seed.
The causative organism of Sprain has been isolated and typical spots of the disease have been reproduced by inoculation with it. It consists of a very short Bacterium, which, being new to the literature, has been named Bacterium rubefaciens.
There is little evidence that this organism enters the fully formed tuber through its skin, and isolated spots which have no apparent connection with the peridenn are a feature of the disease. It is suggested that the organisms enter at a very early stage through the stomata or lenticels of the tuber‐bearing stolon, remaining quiescent in the water‐filled intercellular spaces of the tuber and becoming active only when the latter ripens.
In potatoes affected with Sprain a certain necrosis of the xylem vessels may occur but may easily be overlooked. This Tracheomycosis is essentially different from that of Corky Bacteriosis.
Corky Bacteriosis produces a browning and lignification of the vascular ring macroscopically resembling the Ring Bacteriosis of B. solanacearum.
It is essentially a disease of the xylem vessels which thereby become closely invested with a thick layer of suberised cork.
Corky Bacteriosis is transmitted from the mother tuber to its progeny by way of the stolons. It is also contracted from infected soil apparently by infection of the stolon or the stolon end of the tuber.
The causative organism of this disease has been isolated and the disease reproduced by inoculation. The organism being new to the literature has been named B. suberfaciens.
THE ACTION OF SULPHUR AS A FUNGICIDE AND AS AN ACARICIDE. PART I
Authors: GOODWIN Wm. , MARTIN H. 
Published: February 2008

Summary.An examination of the various theories put forward to account for the fungicidal action of sulphur when applied, not to the plant or fungus, but to a heated surface, has been carried out by chemical methods, and it is concluded:

That, since the volatile agent is capable of passing a glass‐wool filter maintained at the temperature of the heated surface, it is gaseous in character.
That the removal of the volatile agent by passage through a cooled glass‐wool filter is proof that it is neither sulphur dioxide nor hydrogen sulphide but is elementary sulphur.
That the condensation of sulphur volatilised from the heated surface appears sufficient to account for the reactions ascribed to particulate sulphur.
THE TURNIP MUD BEETLES (HELOPHORUS RUGOSUS OL. AND HELOPHORUS PORCULUS BEDEL.)
Authors: PETHERBRIDGE F. R. 
Published: February 2008

Summary. Helophorus rugosus Ol. and Helophorus porculus Bedel, have caused serious damage to late sown white turnips in several cases in the east of England during the last few years.A case in which the growing points of white turnips (planted out for seed growing) were eaten out by the larvae is recorded.Swedes and rape are damaged by these pests but not to the same extent as white turnips.Kale and cabbages are only slightly damaged.Lettuces were seriously damaged in Surrey in 1924.One case of an attack on beans by H. rugosus was also noticed. Most of the damage is caused by the larvae which gnaw or tunnel into the “bulb” of the turnip as well as feeding on the developing leaves. The adults also feed on the leaves.Eggs are probably laid in August and the larvae live from August until April or May.Pupation takes place in April or May and pupae live about three weeks.Adults were found from May until the following March.Descriptions of the larval, pupal and adult stages are given.Late sowing and frequent cruciferous crops appear to predispose plants to attacks.
THE METAMORPHOSIS AND BIOLOGY OF RHYNCHAENUS ALNI L. (COLEOPTERA)
Authors: OLDHAM JOHN N. 
Published: February 2008

Summary.The leaf‐mining habits of the species of the genus Rhynchaenus (syn. Orchestes) are well known and Rh. alni L. was found in Warwickshire, England, to be causing a considerable amount of damage to the foliage of elm trees through the mining of the larvae and feeding of the adults. This species is known to attack both Ulmus campestris and Alnus glutinosa, and a historical review of the literature dealing with the beetle has been written in an attempt to elucidate the misunderstandings and settle the controversy concerning the host plant and specific name of the insect.Brief descriptions of the adult and egg have been given. The first stage larva, which differs from later stages, has been shortly described, while a note has been added on the intermediate stages. The external morphology of the full‐grown larva and of the pupa has been described in detail.The insect has but one generation in the year, in the Warwickshire area, and the life history and general biology have been discussed.During the investigations it was observed that a considerable number of hymenopterous parasites were attacking this insect. From material gathered, eight distinct species of parasites have been reared, and identified from Rh. alni L. of which seven belong to the Chalcidoidea and one to the Ichneumonoidea.
STUDIES OF WOOD‐DESTROYING FUNGI I. POLYPOBUS HISPIDUS (FRIES)
Authors: NUTMAN F. J. 
Published: February 2008

SUMMARY.The characteristics of the Polyporus Msjndus, when grown on artificial media, both solid and liquid, are described and compared with those given by Baxter.Growth on wood of ash under laboratory conditions produces a rot which is indistinguishable from that occurring naturally. The distribution of the hyphae in the wood is described.The mode of penetration of the cell‐wall by the hyphae is figured. It is apparently by pits in the early stages of decay, but by bore‐holes, formed entirely by enzyme activity, in‐the more advanced rot.The rate of growth of the fungus under controlled conditions has been measured, and shown to be 0–5 cm. per month.Successful inoculation experiments have been carried out with young trees, confirming the results of Baxter, who states that the fungus can attack young, living sap wood.An investigation of the enzymes produced by the mycelium has been carried out, and a method evolved for demonstrating the presence of a ligninase. This is a modification of Czapek's “hadromal” reaction.The following enzymes are shown to be present in the mycelium: emulsin, diastase, invertase, ligninase, hemicellulase, oxidase, and catalase. The list is not intended to be exhaustive.The writer desires to express his thanks to Mr W. R. Day, of the Imperial Forestry Institute, Oxford, and to Dr W. Brown, of the Royal College of Science, for helpful criticism and advice. Also to Mr R. S. Pearson, C.I.E., F.L.S., the Director of Forest Products Research, for permission to publish this paper.
THE CONTROL OF “BUNT” IN WHEAT
Authors: WESTON W. A. R. DILLON 
Published: February 2008

SUMMARY.

Results of control experiments over a period of four years are given. The wet treatment, with formaldehyde and copper sulphate, are compared with the dry treatment, using copper carbonate.
The dusting method is discussed. It is shown that infection varies directly with the spore load and that the efficiency of the dusting treatment is proportional to the rate of contamination. For the usually slightly contaminated seed samples this treatment has been effective in controlling bunt.
The practical aspect of dusting wheat is discussed and its cost compared with the other treatments.
A report is given of the feeding of dressed wheat to poultry.
The Action Of Sulphur As A Fungicide And As An Acaricide
Authors: GOODWIN WM. , MARTIN H. 
Published: February 2008

SUMMARY.The conclusion arrived at by chemical methods, that the volatile agent produced when sulphur is applied to a heated surface is gaseous sulphur, has been subjected to biological tests in which the fungi Ery‐siphe graminis and Sphaerotheca Humulind the gall mite Eriophyes ribis were employed.The fungi were found not to be sufficiently sensitive to yield satisfactory and concordant results and strong support is given to the view that actual contact of the sulphur particle with the fungus is necessary before fungicidal action can occur.It was shown that the agent present in air passed over heated sulphur and responsible for the death of the gall mite was not removed by filtration through a heated glass‐wool plug, this observation being contrary to the view that the toxic agent is produced initially in solid form.Filtration through a cooled glass‐wool plug only removed part of the volatile agent and it was shown that the gall mite is affected by the traces of sulphur volatilised at ordinary temperatures.The results of the experiments with the gall mite were in complete accord with those obtained in the previous chemical work.At relatively large concentrations sulphur dioxide and hydrogen sulphide are without permanent effect upon the gall mite and these gases are therefore not responsible for the acaricidal action of sulphur.
THE INFLUENCE OF BRIGHT SUNSHINE UPON THE TOMATO UNDER GLASS
Authors: BEWLEY W. F. 
Published: February 2008

SUMMARY.

The tomato crop produced in glasshouses is affected by prevahg weather conditions.
The yield per acre varies directly in relation to the total hours of bright sunshine during the period April 1st t o September 30th.
Total sunshine also affects the potash requirement of the tomato, less potash being required during bright sunny weather than under dull conditions.
SOME PROPERTIES OF THE CELL‐WALL OF COTTON‐HAIRS
Authors: BARRITT By N. W. 
Published: February 2008

Summary.

The cell‐wall of the living cotton‐hair is under tension and its diameter is unaffected by osmotic pressure or the death of the cell.
Increase of diameter of the uncollapsed hair by swelling in caustic soda varies inversely as the diameter of the hair in the case of fine cottons, and does not occur with coarse cottons.
The diameter of the uncollapsed cotton‐hair varies inversely as the intrinsic strength of the collapsed hair.

I have to thank Dr R. H. Pickard, F.R.S., and his colleagues Miss Calvert, M.Sc, and Miss Clegg, M.Sc, of the Shirley Institute, Manchester, for their very helpful criticisms.
CARBON DIOXIDE PRODUCTION IN SANDS AND SOILS IN THE PRESENCE AND ABSENCE OF AMOEBAE
Authors: CUTLER By D. WARD , CRUMP L: M. 
Published: February 2008

Summary.Experiments are described on carbon dioxide production from soil and sand cultures containing a species of bacterium with and without amoebae. The following results were obtained:

Carbon dioxide production and bacterial numbers are correlated provided that amoebae are not present, or are present in very small numbers.
The bacteria are more efficient as producers of carbon dioxide when their numbers are not rising and less efficient when their numbers are increasing. This does not hold for young cultures. Also each bacterium becomes less efficient as the density of the population increases.
The amoebae cause a decrease in carbon dioxide production in sands containing peptone, but an increase in sands containing mineral salt solution with glucose or soil extract