bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE FERN MTTE. (TARSON EMUS TEPIDARIORUM, WARBURTON)
Authors: CAMERON W. P. LEGERWOOD 
Published: February 2008

SUMMARY AND CONCLUSION.Fern mite (Tarsonemus tepidariorum, Warburton) is of distinct economic importance. It attacks the younger parts only of the fern (Asplenium bulbiferum and its varieties), causing the fronds to become. distorted and the plant to be dwarfed so that it is unsaleable. The disease spreads rapidly in a greenhouse due to the rapid multiplication of the mite and the very short life‐cycle of 17 days on the average. All stages of the pest may be found during the summer, and the winter is passed mainly as an adult female, although a few eggs may also be found at that time. The mites spread from one nursery to another by the introduction of infested plants; from one plant to another by crawling from leaf to leaf where these touch, and probably by walking along the surface. of the moist earth; and by the planting of young “pips” taken from infested parents. The disease is difficult to control.Preventive measures offer more chance of success than do remedial. The young “pips” should be planted clean, and then kept free from the pest by means of deterrent sprays. The “pips” are treated with some insecticide before planting.Badly infested plants should be burnt and the soil and houses should be sterilised.It is essential to produce healthy plants. To obtain this, certain factors are important, such as proper ventilation, adequate drainage and the correct degree of temperature and humidity.Potash manures and lime are good. Nitrogenous manures should be sparingly.Rotation of the greenhouse crops is advisable.Plants would be produced clean, if they could be propagated from spores.
THE ANATOMY OF THE LEAF‘ OF A NEW FIBRE PLANT
Authors: DENNISTON R. H. 
Published: February 2008

RESUME.The valuable fibre portion of this leaf consists in the fibre groupa scattered through the parenchyma of the abaxial portion of the leaf and in the groups of fibres accompanying each fibro‐vascular bundle.The bast fibres are composed principally of cellulose, as indicated by their ready solubility in copper‐oxide‐ammonia solution, and by their violet colour when treated with zinc‐chlor‐iodine and blue colour with iodine and sulphuric acid.The fibres are not pure cellulose, however, as is shown by their red colour when treated with phloroglucin, and their yellow colour when treated with anilin sulphate.The outer part of the fibre‐wall shows clear evidence of spiral structure under the action of cuprammonis. The treated fibre presents the appearance of a series of beads of unequal size. After repeated applications of the reagent, the constricting portion of the fibre swells and loosens. All portions of the fibre give the cellulose reaction with zinc‐chlor‐iodine, but the spiral constricting portion takes a violet colour in advance of the inner portion of the fibre and can then be seen very distinctly.
STUDIES ON OSCINELLA PRIT LINN.: SUPPLEMENTARY DATA ON THE RELATION BETWEEN VARIETAL DIFFERENCES OF OAT PLANTS AND SUSCEPTIBILITY TO INFESTATION
Authors: CUNLIFFE NORMAN , FRYER J. C. F. 
Published: February 2008

SUMMARYDuring the year 1924 additional data, in relation to varietal resistance to attack, were collected by repeating as nearly as possible the investigation conducted during the previous year, with the exception that only those varieties of oat were used, which were most (Goldfinder and New Abundance) and least resistant (Superb and Supreme).During the second season, during which, on the whole, conditions were unfavourable to damage by frit fly, varietal differences were again effective so far as stem infestation was concerned. The two varieties, Goldfinder and New Abundance, were significantly resistant as compared with the variety Supreme, similar differences being observed in the two seasons. Very late sowing indicated that varietal differences among very young plants were ineffective in influencing extent of infestation.Small significant differences were observed in relation to the grain infestation, but from the evidence available it would appear that constant values for these differences are unlikely to occur over a period of years, because extent of infestation is largely dependent on the history of the crop during the early growing period.
INFLUENCE OF LEAD AND THE METALLIC IONS OF COPPER, ZINC, THORIUM, BERYLLIUM AND THALLIUM ON THE GERMINATION OF FROGS‘ SPAWN AND ON THE GROWTH OF TADPOLES1
Authors: DILLING WALTER J. , HEALEY C. W. 
Published: February 2008

SUMMARY

In these experiments lead salts proved to have a higher inhibitory influence on the germination of the frog's ovum than the salts of other metals tested and they also proved capable in weaker solutions of retarding the growth of tadpoles without causing their early death. Of the other metals tested thorium was active in checking germination; the others much less so. Zinc, copper and thallium were more toxic to the emerged tadpoles than lead. Beryllium was relatively inert. Hanzlick and Presho's observations on pigeons fed with pure metals led them to conclude that, as regards the power of reducing body weight, the action of other metals was much less than that of lead, which they regard as having a specific toxicity (6). The present writers do not consider that these effects are “specific” or peculiar to lead, but they are relatively more marked with its salts. Locke's (9) experiments with tadpoles showed that lead was less directly toxic to them than zinc and much less than copper; this we have confirmed, but our experiments suggest that the “oligodynamic” action of lead decreases as the embryo ages.
These experiments suggest that lead is more toxic to germinating tissues than the other metals tested and afford an explanation of its abortifacient action on the basis that it is much more toxic to the embryo than to the adult tissues of the parent. Subsequent experiments by Blair Bell, Hendry and Annett on pregnant rabbits have shown that after injections of colloidal lead there occurs a coagulation necrosis in the ectodermal tubules (trophoblast) of the foetal placenta; this rapidly spreads throughout the foetal ectoderm and into the adjacent superficial tissues of the maternal placenta so that the necrotic foetal placenta is soon cast off. They conclude that lead has a selective affinity for the chorion epithelium and that abortion can be produced by the action of lead on the foetal ectoderm (trophoblast) without the maternal organism being in any way affected.

On the findings of the present experiments these observers tried thorium as a substitute for lead but found it had no specific or toxic action on the chorion epithelium and that the abortifacient action of copper and thallium was uncertain and due to haemorrhage in the maternal tissues of the uterus (2).

It has also been possible to confirm by these experiments some of the essential features recorded in the literature, e.g. (a) the toxicity of lead towards the female germ cell as higher than that to the male cell as was indicated in Weller's (15) experiments; (b) the greater susceptibility of very young animals to lead and progressive tolerance as the animal ages; and (c) the retardation of growth in the tadpole is comparable with the undersized offspring delivered from the mammal and the retardation of growth noted after birth by Weller (16).
AN INTRODUCTORY NOTE ON TWO BACTERIA CAUSING AN INTERNAL ROT OF COTTON BOLLS
Authors: HOPKINS J. C. 
Published: February 2008

SUMMARY

Two organisms have been isolated which are capable of producing an internal rot of at least five varieties of cotton bolls.
Inoculation experiments and resulting physiological phenomena are described and the similarity between the two rots demonstrated.
The association of one organism with the anthracnose fungus is pointed out and dual infection of a number of varieties of cotton bolls discussed; the resistance of Sea Island and Cauto varieties to the disease is suggested.
Detailed descriptions of both organisms and their reactions to various standard media are given.
FURTHER EXPERIMENTS ON THE USE OF SULPHUR IN RELATION TO WART DISEASE OF POTATOES
Authors: ROACH W. A. , BRIERLEY Wm. B. 
Published: February 2008

SUMMARYPlots of light sandy soil at Ormskirk carefully fenced in to prevent re‐contamination were treated with sulphur at rates of 10 cwts. and 15 cwts. per acre. The sulphur was incorporated by means of the Simar Rotary Tiller. A planting of King Edward and a replanting of Arran Chief varieties in the treated plots almost completely failed to grow. On the few plants which developed, Wart Disease was present in less quantity than on the plants in the untreated controls.A plot of heavy clay soil at Hatfield was treated with 3 tons of sulphur per acre incorporated by means of the Simar Rotary Tiller. Plants of King Edward variety grew well but showed a considerable amount of Wart Disease.Plots of land at Ormskirk which in 1924 had received amounts of sulphur varying up to one ton per acre were in 1925 given a dressing of lime and planted with Majestic variety of potatoes. No effect of the previous treatment on the crop was apparent.We are indebted to the Piccard Pictet Company for the loan of the 4 h.p. Simar Rotary Tiller used in these experiments.
STUDIES ON CONTACT INSECTICIDES
Authors: TATTEESFIELD F. , GIMINGHAM C. T. , MOREIS H. M. 
Published: February 2008

SUMMARY

An account is given of laboratory experiments on the toxicity to Aphis rumicis L. of extracts of a considerable number of plants, including some tropical fish‐poisons, Lupins, Broom, Gorse, Lobelia and others.
Alcoholic extracts of certain tropical plants used as fish‐poisons are shown to have a high toxicity under the conditions of the experiments. The roots and stems of White Haiari, and the stems of Black Haiari (both species of Lonchocarpus from British Guiana), the roots of Tephrosia toxicaria and the leaves of T. Vogelii all possess notable insecticidal properties. The roots and stems of T. Candida are less toxic.
Preliminary experiments indicate that the Haiaris and T. Vogelii and T. toxicaria, when tested as stomach poisons, exert both a repellent and toxic action to caterpillars.
Certain derivatives isolated from these plants were tested. The most toxic substance obtained from the Haiaris is shown to be identical with tubatoxin, the crystalline poison found in Derris elliptica. Tubatoxin proved to be several times more toxic than nicotine. In the case of Tephrosia Vogelii and T. toxicaria, the most toxic substances isolated were resinous in nature. Crystals closely corresponding to tephrosin, as isolated by Hanriot, were less toxic.
A number of alkaloids was also investigated. Cytisine and lobeline, known to have a physiological action on higher animals similar to that of nicotine, were found somewhat less toxic than nicotine to aphides. Eserine was the only other alkaloid tested which approached nicotine in toxicity.
INVESTIGATIONS INTO INSECTICIDES FOR ROOT MEALY BUG AND ROOT APHIS
Authors: SAUNDERS WINIFRED H. 
Published: February 2008

SUMMARYOf the list of possible remedies the following are the least desirable for using on a large scale for the reasons stated.Nicotine Uncertain in its action and being poisonous must be used cautiously.Pyridine Highly offensive odour.Petroleum Inflammable. Bugs dislike it, they often leave the pots and under certain conditions they may escape death.Methyl alcohol Inflammable, action slow.Acetone Will not mix with water—injections into the soil are impracticable.Fuel oil Bugs escape from the pots.Miscible fusel oil No effect.The three following stand out as being the most effective and suitable:Tetrachlorethane (Westoran)Trichlorethylene (Westropol)Potassium sulpho‐carbonateThe root mealy bug and root aphis living under similar conditions in pots, adopting similar methods of feeding and protection, respond similarly to any particular treatment. The grower may, therefore, cope with both pests by the application of a common remedy.
INFLUENCE OF PROTOZOA ON THE PROCESS OF NITROGEN FIXATION BY AZOTOBACTER CHROOCOCCUM
Authors: CUTLER D. W. , BAL D. V. 
Published: February 2008

SUMMARY

Increased nitrogen fixation by Azotobacter chroococcum in the presence of protozoa, as shown by Nasir, has been confirmed
The same effect is found, using soil as a medium.
There is a definite relationship between the efficiency of the strain used, the incubation period and the concentration of mannitol employed.
The feeding action of Colpidium colpoda and Hartmanella hydlina on Azotobacter has been demonstrated.
The reason for increased nitrogen fixation appears to be due to the efficiency of Azotobacter being maintained for a longer period.
CARBON DIOXIDE IN RELATION TO GLASSHOUSE CROPS
Authors: OWEN O. , SMALL T. , WILLIAMS P. H. 
Published: February 2008

SUMMARY

The rate of germination of tomato seeds is practically unaffected when the seed boxes are exposed to atmospheres enriched with carbon dioxide.
Increases of over 20 per cent, in marketable tomato crops result when the plants are subjected to atmospheres containing 0.6 per cent, of CO2 for 1 or 2 hours daily.
Cucumbers heated with atmospheres containing 0.9 per cent. CO2 for 1 hour daily showed an increase in crop of 16 per cent.
In the case of the 1925 tomato crop, and to a less degree of the 1924 crop, a considerable part of the increased picking is manifested in June, when market prices are high.
In its effect on the crop carbon dioxide generated slowly at the soil surface is not as beneficial as the gas when generated quickly and mixed with the air surrounding the plants.
Plants grown in houses which have been used for carbon dioxide experiments show an increased susceptibility to infection by Colletotrichum atramentarium.
When carbon dioxide is generated quickly in a house an appreciable loss of this gas always occurs. This loss appears to be independent of temperature and varies directly with the amount of ventilation.
Experiments with apparatus devised for the use of carbon dioxide on a commercial scale were unsuccessful owing to the inadequacy of the apparatus.
A STUDY OF TWENTY‐FOUR STRAINS OF ACTINOMYCES AND THEIR RELATION TO TYPES OF COMMON SCAB OF POTATO
Authors: MILLAED W. A. , BURR SYDNEY 
Published: February 2008

SUMMARYThe difficulty of reconciling various cultures of the scab organism with any one defined type of A. scabies (Thaxter) Güssow is discussed.Inclusion of all such cultures into one A. scabies group has no justification.A technique has been evolved whereby the cultural characters of Actinomyces may be maintained in sub‐culture.Twenty‐four Actinomyces strains were isolated from potato scabs and other sources, and the cultural and morphological characters of these have been worked out and described.Three pairs of duplicate strains appeared, but with these exceptions, the differences between the strains were of specific rank.One of the species appears to be identical with Thaxter's original scab organism and is thus referred to A. scabies (Thaxter) Güssow; the remainder are new and have accordingly been named.Eleven of the species were found to produce scab on potatoes.The various type a of common scab have been defined, and it has been shown that type of scab is dependent on the infecting Actinomyces species. The variety of potato may modify but cannot materially change this type. A. scabies (Thaxter) Güssow (emend. M. and B.) produced a deeply furrowed scab apparently identical with the “Deep Scab” described by Thaxter. This species was also found to attack the roots and stolons of potato plants.The occurrence of scab in virgin soils and the predominance of certain scab types in certain soils and in different years are discussed.
THE INCIDENCE AND INTENSITY OF PUCCINIA GLUMARUM ERIKS. AND HENN., ON WHEAT INFECTED AND NON‐INFECTED WITH TILLETIA TRITICI WINTER, SHOWING AN APPARENT RELATIONSHIP BETWEEN THE SUSCEPTIBILITY OF WHEAT PLANTS TO YELLOW RUST AND TO BUNT
Authors: WESTON W. A. R. DILLON 
Published: February 2008

Summary.In the season 1925–6 an interesting relationship was noticed between yellow rust of wheat, Puccinia glumarum and bunt or stinking smut of wheat, Tilltia tritici; it was observed that:

Bunted Little Joss wheat plants were badly rusted and that plants free from bunt were free or comparatively free from rust.
Bunted plants of other wheat varieties were definitely more rusted than plants free from bunt.
It is suggested that rust resistance which cannot be broken down artificially may be broken down by natural contamination of wheat with the bunt fungus.
THE LIFE HISTORY AND BIONOMICS OF A BRITISH PHYTOPHAGOUS CHALCIDOID OF THE GENUS HARMOLITA (ISOSOMA)
Authors: JAMES E. C. 
Published: February 2008

Summary.This paper is a contribution to our very scanty knowledge of the British Harmolita, a phytophagous genus of the superfamily Chalcidoidea (Hymenoptera). Many species of this genus are pests on cereals and cultivated grasses; one species, Harmlita tritici, is the notorious joint‐worm of America and Russia, whilst species attacking many other cereals and grasses have been recorded in Europe and America. An account is here given for the first time of the life history and biology of a British species of Harmolita, namely Harmolita graminicola, which is a gall former on couch grass (Triticum repens).The larva of another undetermined species of Harmolita, also gallicolous on Triticum repens is figured and briefly described.The adult of Harmolita graminicola begins to emerge in the last week of June and continues to appear during the first week of July. When the inflorescence has appeared through the sheathing leaves the female fly will not lay eggs on them. One egg is deposited on each culm just beneath the rudimentary inflorescence, the ovipositor of the fly piercing the sheathing leaves in order to reach the desired position. The Harmolitae of both species were bred in captivity and the length of the period of incubation of the egg was found to be between three and four weeks. Experiments were conducted to ascertain whether parthenogenesis occurred in this species. The results were negative although perhaps not numerous enough to be conclusive.The larva possesses four instars and moults three times whilst feeding, another moult occurring at pupation. The larval instars can be differentiated most exactly by the state of development of the sub‐apical tooth on the mandible. The sub‐apical tooth is absent from the mandibles of the first instar; only incipiently developed in the second instar; better developed in the third and fully formed in the fourth instar. The larva becomes full fed in October and hibernation takes place in the larval stage. Pupation begins to occur near the end of April but the great majority pupate in the middle of May.There is a short semi‐pupal stage of from 12 to 24 hours duration immediately before the pupal moult takes place. The pupal stage lasts about 40 days and there is only one generation each year. The larva of Bracon erythrostictus (Lyle) was found to be parasitic on Harmolita in the latter's larval stages; no other insect parasites were found. Both Harmolita graminicola (Gir) and the undetermined species refused to breed on wheat or any other plants of the Triticum genus although many attempts were made to induce them to do so.
ON FORMS OF THE HOP RESISTANT TO MILDEW (SPHAEROTHECA HUMULI (DC.) BURR.)
Authors: SALMON. Prof. E. S. 
Published: February 2008

Summary.

Three varieties of hops which had previously shown complete resistance to the attacks of S. Human, became slightly infected in the greenhouse in the spring of 1926.
The susceptibility shown was only temporary; all the infected plants during May and June again acquired their power of complete resistance.
The conidia produced on an “immune” plant proved unable to infect that plant, although able to infect a susceptible variety.
It appears probable that abnormal weather conditions (possibly low temperature) brought about the temporary susceptibility.
GRAFTING EXPERIMENTS WITH VARIETIES OF HOPS RESISTANT TO TICE HOP POWDERY MILDEW, SPHAEROTHECA HUMULI (DC.) BURR.
Authors: SALMON Prof. E. S. , WARE W. M. 
Published: February 2008

Summary.

Twenty composite plants were built up by grafting either a scion of an immune variety of hop on a susceptible stock, or vice versa. Inoculation of young leaves of the scion, after a considerabll growth of the latter had taken place since grafting, showed that no change had been effected in the varietal immunity or susceptibility in relation to Sphaerotheca Humuli.
In the above experiments, scions of six different immune varieties were grafted on stocks of four different susceptible varieties and scions of four different susceptible varieties were grafted on stocks of five different immune varieties.
The results obtained render it improbable that immunity or susceptibility to S. Humuli is connected with any translocatable substance in the hop plant.
STUDIES ON CONTACT INSECTICIDES
Authors: TATTERSFIELD F. , GIMINGHAM C. T. 
Published: February 2008

Summary.

The toxicities to Aphis rumicis L. of the fatty acids from formic to stearic and of the sodium and ammonium salts and methyl esters, applied as spray fluids, have been quantitatively determined. Two un‐saturated acids, undecenoic and oleic, are included.
There is a rise in toxicity of the acids with increase of molecular weight as the series is ascended from acetic to undecylic acid. Formic acid is exceptional. Beyond undecylic acid, there is a fall in toxicity, and acids higher in the series than tridecylic show only slight toxic action.
The sodium salts of the fatty acids are in most cases much less toxic than the corresponding acids, though the difference is less marked with the higher acids. Oleic acid and sodium oleate are of the same order of toxicity.
The ammonium salts are also generally less toxic than the corresponding acids, but the differences are much less than in the case of the sodium salts. With some of the higher acids, e.g. myristic and oleic, neutralisation with ammonia increases toxicity. The relatively high toxicity of the ammonium salts may be due, at least partly, to liberation, by hydrolysis, of free fatty acid in a very finely divided state.
Methylation of the fatty acids reduces toxicity; all the methyl esters are less toxic than the acids or ammonium salts.
Both the ammonium salts and the methyl esters show, like the acids themselves, increase of toxicity with increase of molecular weight up to a certain point. The formates are exceptional.
The fatty acids do not show marked toxicity to the eggs of Belenia tetralunaria Hüfn. at concentrations below 2 per cent.
Possible relationships between certain physical properties (physical state. volatility, dissociation constants, partition coefficients and surface tension) of the fatty acids and their insecticidal action are discussed.
Determination of partition coefficients as between olive oil and water and comparison of the figures with the relative toxicities show a steady rise in toxicity with a decrease in the partition coefficients (water/oil) from acetic to capric acid. Formic acid is again exceptional. With lauric and oleic aoids there is a break in the correlation. The bearing of the solubility relationships of the acids on these results is considered.