Showing papers in "Canadian journal of research in 1936"
TL;DR: Permeability is found to increase greatly with hardening, whether induced by low temperature or other conditions, and it seems to parallel closely the seasonal changes in frost resistance.
Abstract: Cell permeability as estimated by the plasmolytic method in various types of plants and for different classes of solute has been studied in relation to frost resistance and the seasonal cycle. Perm...
66 citations
TL;DR: The effect of osmotic pressure in reducing the amount of ice formation is enhanced in woody plants by the condition that only about half the cell volume is occupied by the osmotically active solution, which increases notably with hardening.
Abstract: The osmotic pressure and non-solvent space of the cells of various types of plant were estimated by the plasmolytic method and related to frost resistance and the seasonal cycle.Osmotic pressure al...
65 citations
TL;DR: It was concluded that auto- as well as allosyndesis had occurred in the A. elongatum × Triticum hybrids and in the F1 of these species crossed on varieties of T. durum and T. vulgare.
Abstract: Meiosis was studied in A. glaucum (2n = 42), A. elongatum (2n = 70), and in the F1 of these species crossed on varieties of T. dicoccum, T. durum and T. vulgare. In A. glaucum a large proportion of the chromosomes formed bivalents with occasional univalents and quadrivalents. A. elongatum was very unusual in that uni-, bi-, tri-, quadri-, quinqui-, sexa-, and octavalent configurations were observed. With one exception the A. glaucum × Triticum hybrids averaged 4.8–6.2 bivalents per nucleus, thus indicating partial homology between one set of chromosomes from each of the parents. In the A. elongatum × Triticum hybrids, numerous multivalent configurations were observed and it was concluded that auto- as well as allosyndesis had occurred. Approximately one set of chromosomes remained unpaired in one collection of T. dicoccum var. Vernal × A. elongatum and approximately two sets remained unpaired in crosses between three varieties of T. vulgare and A. elongatum.Two of the crosses exhibited an abnormally small...
48 citations
TL;DR: Stripe rust collected on species of Hordeum, Elymus and Agropyron has been studied in the greenhouse and has in all cases shown ability to attack wheat varieties.
Abstract: A study was made of the distribution of Puccinia glumarum (Schm.) Erikss. and Henn. in Canada, its specialization, host range, and reaction to environmental conditions. Unlike Puccinia graminis Pers., this rust has a limited distribution, being confined to British Columbia, Alberta, and the western half of Saskatchewan. The natural hosts include a number of native grasses, particularly Hordeum jubatum L. and certain species of Agropyron, Elymus, and Bromus. Wheat and barley also become infected although to a rather limited extent: Stripe rust collected on the above-mentioned hosts has been studied in the greenhouse and has in all cases shown ability to attack wheat varieties. In all instances where identification of physiologic forms was carried out the rust strains were classified as either form 8 or form 13 of wheat stripe rust, the latter form being the more common. The fact that the present authors have collected known physiologic forms of wheat stripe rust on species of Hordeum, Elymus and Agropyron,...
38 citations
TL;DR: Grown under greenhouse conditions the F1 hybrids proved to be self-sterile and perennial in habit, with hybrid vigor strongly marked, and intermediate in morphological characters, but with somewhat more resemblance to Agropyron than to wheat.
Abstract: Two species of tetraploid (2n = 28) and three varieties of hexaploid (2n = 42) wheat were crossed with A. glaucum (2n = 42), and A. elongatum (2n = 70), with an average crossing success of 18%. The seed obtained from tetraploid wheat × A. glaucum was slightly plumper and germinated better than that obtained from tetraploid wheat × A. elongatum. On the other hand, hexaploid wheat × A. elongatum gave decidedly plumper and better germinating seed than hexaploid × A. glaucum.Grown under greenhouse conditions the F1 hybrids proved to be self-sterile and perennial in habit, with hybrid vigor strongly marked. The hybrids were, in general, intermediate in morphological characters, but with somewhat more resemblance to Agropyron than to wheat. This dominance, whole or partial, was more noticeable in the A. elongatum than in the A. glaucum crosses. Dominance phenomena are discussed in relation to current theories.
35 citations
TL;DR: Twenty-three species and one variety belonging to three subgenera of the family Simuliidae are recorded and described, including both sexes of adults and the pupae and cocoons of these species.
Abstract: Twenty-three species and one variety belonging to three subgenera of the family Simuliidae are recorded and described. Of these, twelve species and the variety are new to science. Only two of the remaining eleven species of other authors have been previously recorded in Eastern Canada; two others, originally described in Europe, are recorded in North America for the first time, and the hitherto unknown male of a fifth species is described. The adult forms and the pupae and cocoons of these species are described, and the genitalia of both sexes of flies are figured. In addition, notes on the habitats, distribution, species associations, and similar information of value in identifying the species are given. Keys to the subgenera and species, including both sexes of adults and the pupae are an important feature.
27 citations
TL;DR: In this article, the spectrum of cerium has been photographed from λ3600 to λ500 A by means of a two-meter grating of 30,000 lines per inch mounted in a vacuum spectrograph, using the vacuum spark and the spark in nitrogen as sources.
Abstract: The spectrum of cerium has been photographed from λ3600 to λ500 A by means of a two-meter grating of 30,000 lines per inch mounted in a vacuum spectrograph, using the vacuum spark and the spark in nitrogen as sources. An analysis of the spectrum of Ce IV results in the location of the 6S − 6P, 6P − 6D, 6P − 7S, 5D − 6P, 6P − 8S and possibly the 6P − 7D multiplets. The ionization potential is approximately 33.3 volts.
25 citations
TL;DR: Two species of Valsa have been isolated more or less consistently from cankers of various ages, and from "die-back" twigs on the peach, and has large light-colored pycnidia containing, though rarely exuding, spores.
Abstract: Two species of Valsa have been isolated more or less consistently from cankers of various ages, and from "die-back" twigs on the peach. In culture, one species, identified as Valsa leucostoma (Pers.) Fr., is hair-brown and has small dark pycnidia exuding cirri when mature. On the host, its stroma is compact in texture, contains no host cells and is delimited beneath by a black zone of carbonized fungal and host cells. Ascospores of V. leucostoma measure 10–17 by 2–4.5 μ. The other species, which has been assigned to V. cincta Fr., is whitish to olive buff in culture and has large light-colored pycnidia containing, though rarely exuding, spores. On the host, the stroma of V. cincta is comparatively loose in texture, contains host cells and is delimited from the cortex of the host by a thin, black zone, sometimes only marginal. Ascospores of V. cincta measure 14–28 by 4–7 μ. In both species, the pycnospores range from 5 to 10 μ in length and 1 to 2 μ in width. These organisms, along with Sclerotinia fructic...
24 citations
TL;DR: In this article, the distribution of light energy among the various orders of the diffraction pattern produced when monochromatic light is passed through a liquid subjected to high-frequency ultrasonic disturbances at frequencies in the region of 5 megacycles per second.
Abstract: Measurements of the distribution of light energy among the various orders of the diffraction pattern produced when monochromatic light is passed through a liquid subjected to high-frequency ultrasonic disturbances have been carried out over a range of ultrasonic intensities at frequencies in the region of 5 megacycles per second. Both progressive and standing wave fields have been studied. Results of the experiments show excellent agreement with the theory of Raman and Nath for the variation in degree of scattering with varying ultrasonic intensity. Absolute measurements of the sound intensity conducted with a torsion pendulum are in good agreement with that expected from the theory for the liquids and light wave-lengths involved.
22 citations
TL;DR: The results indicate that there is a critical temperature below which moderate periods of heating have little effect on viability, and at higher temperatures the germinating power falls off rapidly.
Abstract: A series of weed seeds comprising seven species and representing five families was studied to determine the effect of heat on subsequent germination. Lethal temperatures for 15 minutes' heating varied from 85° to 105 °C.The results indicate that there is a critical temperature below which moderate periods of heating have little effect on viability. At higher temperatures the germinating power falls off rapidly.
21 citations
TL;DR: Strawberry and tobacco seedlings growing in seed-bed muck heavily infested with Thielaviopsis basicola, and in soil from a commercial plantation where strawberry root rot had occurred in severe and typical form, suggested the co-operative investigation, which results are embodied in this paper.
Abstract: Similarity of organisms encountered in studies of black root of strawberry and of tobacco, respectively, carried out contemporaneously but independently, suggested the co-operative investigation, the results of which are embodied in this paper. Strawberry and tobacco seedlings growing (i) in seed-bed muck heavily infested with Thielaviopsis basicola (Berk.) Ferraris, and other organisms known to be pathogenic on tobacco, (ii) in soil from a commercial plantation where strawberry root rot had occurred in severe and typical form, and (iii) in greenhouse compost soil, were examined microscopically daily, commencing a few hours after germination and continuing throughout a period of four weeks. Organisms observed definitely within root tissues of both hosts included the "phycomycetous mycorrhizal" fungus, T. basicola (observed in plants grown in muck only), Rhizoctonia (Solani and endophytic orchid types), forms of Pythium, Asterocystis (Olpidiaster), certain unidentified fungi, a minute filamentous alga and ...
TL;DR: The mean heat capacities over 10° intervals from − 80° to 120°C have been determined for silver, nickel, zinc, cadmium and lead in this article, and the average deviation of the points from a smooth curve was in eac...
Abstract: The mean heat capacities over 10° intervals from − 80° to 120 °C. have been determined for silver, nickel, zinc, cadmium and lead. The average deviation of the points from a smooth curve was in eac...
TL;DR: A study of the susceptibility of wheat plants to drought at different stages of development showed that the shooting and the soft-dough periods were the most critical, from the point of view of grain yield.
Abstract: The results of a number of preliminary investigations regarding the nature of drought resistance in wheat are presented.A study of the susceptibility of wheat plants to drought at different stages ...
TL;DR: Two new species of cestodes, five of nematodes, two of Acanthocephala and one linguatid are recorded from carnivores in Trinidad, B.W.I.
Abstract: Two new species of cestodes, five of nematodes, two of Acanthocephala and one linguatid are recorded from carnivores in Trinidad, B.W.I.
TL;DR: In this article, four new methods were outlined for the synthesis of polyethylene glycols, and they were applied to polypropylene and polyethylenitrile glycol.
Abstract: Four new methods are outlined for the synthesis of polyethylene glycols.Ethylene glycol heated to 190 °C. with 0.3% of its weight of iodine as a catalyst loses water to form diethylene- and other p...
TL;DR: Seed and seedling inoculation methods proved unsatisfactory for testing the pathogenicity of bacterial isolates derived from lesioned wheat plants, but inoculation accompanied by wounding of the young primary leaf, still enclosed in the coleoptile, proved to be a quick and effective method.
Abstract: A study was made of the etiology of wheat discolorations that resembled bacterial black chaff. Three distinct types were found. One of these was caused by Phyt. translucens f.sp. undulosum, the bacterial black chaff organism; another yielded Alternaria consistently on isolation; and a third, internodal melanism, appeared to be physiological in origin. Phytomonas alrofaciens was occasionally present in bacterial black chaff lesions.Seed and seedling inoculation methods, unaccompanied by wounding, proved unsatisfactory for testing the pathogenicity of bacterial isolates derived from lesioned wheat plants, but inoculation accompanied by wounding of the young primary leaf, still enclosed in the coleoptile, proved to be a quick and effective method. Soil inoculation methods were ineffective. A method, involving a minimum of mechanical injury to the tissues, was developed for flooding the mesophyll of wheat leaves with a bacterial suspension.
TL;DR: The influence of the configurational relations of the hexoses on the ability of a Streptococcus cremoris strain to produce acid from lactose in milk and in broth has been studied as discussed by the authors.
Abstract: The influence of the configurational relations of the hexoses on the ability of a Streptococcus cremoris strain to produce acid from lactose in milk and in broth has been studied.With casein digest broth as the nitrogen source, the organism was carried by serial transfers in 10 different carbon sources; at every transfer the cultures were inoculated from the sugar broths into milk, and the clotting times of the respective milk tubes determined.The carrying of the culture in sucrose, maltose, dextrin or starch has no influence on the acid-producing ability of the organism.Glucose, mannose, fructose, and salicin exhibit a marked inhibiting effect on the rate and amount of acid production in milk and in lactose broth.Although galactose and lactose fail to inhibit completely the activity of the organism, a restraining influence on acid production is to be observed. It is suggested that the inhibitory activity of glucose or one of its metabolic products may be a cause of the sudden or gradual loss of vitality ...
TL;DR: Data has been obtained that support the hypothesis that the Cervidae are normal hosts in the trematode's life-cycle, that the large Bovidae do not act in this capacity and that Ovis aries may act as a definitive host but is severely injured by even light infestations.
Abstract: Comparative studies have been made on the tissue reactions in fascioloidiasis magna in Bos taurus, Bison bison, B. taurus × B. bison, Cervus canadensis, Odocoileus virginianus and Ovis aries. Data have been obtained that support the hypothesis that the Cervidae are normal hosts in the trematode's life-cycle, that the large Bovidae do not act in this capacity and that Ovis aries may act as a definitive host but is severely injured by even light infestations. The cellular bases of the defence reactions in the above ruminants are recorded.
TL;DR: A tetraploid sector on a barley spike was induced by germinating and growing barley for seven days at 35 °C and compared with diploid florets from the same spike to study chromosome pairing and chiasma formation.
Abstract: A tetraploid sector on a barley spike was induced by germinating and growing barley for seven days at 35 °C. Tetraploid and diploid florets from the same spike were compared with respect to chromosome pairing and chiasma formation.
TL;DR: This paper describes the standardization of the technique that has been evolved to facilitate the comparative testing of various substances that can be added to manure with the object of effectively destroying the free-living stages of bursate nematodes.
Abstract: This paper describes the standardization of the technique that has been evolved to facilitate the comparative testing of various substances that can be added to manure with the object of effectively destroying the free-living stages of bursate nematodes. Methods of controlling the experiments are described and the significance of the results discussed.
TL;DR: The male of Tetrameres crami is described and the female is redescribed in the light of further studies, and the life history has been elucidated and the larval stages described.
Abstract: The male of Tetrameres crami is described and the female is redescribed in the light of further studies. The life history has been elucidated and the larval stages described. Two fresh-water amphip...
TL;DR: Genetic studies were made in the F2 and F3 generations of the crosses, and it was found that the character glume color was controlled by either one or two factor pairs in the cross Selection I-28-60 × Milturum, and by two factor Pair in the crosses Reward × Caesium andCaesium × Marquis.
Abstract: Genetic studies were made in the F2 and F3 generations of the crosses, Selection I-28-60 × Milturum, Reward × Caesium, and Caesium × Marquis. It was found that the character glume color was controlled by either one or two factor pairs in the cross Selection I-28-60 × Milturum, and by two factor pairs in the crosses Reward × Caesium and Caesium × Marquis. The characters, awning, straw color, glume pubescence and spike regularity were each governed by one factor pair, while three factor pairs were operative in the inheritance of seed color.Polymeric factors apparently control the inheritance of the quantitative characters straw strength, plant height, earliness and grain yield. A partial dominance of strong straw and earliness was found in the crosses Reward × Caesium and Caesium × Marquis. Tallness and low grain yield were partially dominant in the cross Reward × Caesium. Evidence for transgressive segregation of earliness was obtained in the cross between Caesium and Marquis.The characters glume color, aw...
TL;DR: The mean heat capacities of silver and nickel between 0 °C and various temperatures from 100° to 500 °C have been determined by the method of mixtures, an all-copper adiabatic calorimeter being used as mentioned in this paper.
Abstract: The mean heat capacities of silver and nickel between 0 °C and various temperatures from 100° to 500 °C have been determined by the method of mixtures, an all-copper adiabatic calorimeter being u
TL;DR: The biology of Ips perturbatus in the Gaspe Peninsula is described from observations made during the summer of 1933 and 1934, and indicates that the two sexes are present in about equal proportions.
Abstract: The biology of Ips perturbatus in the Gaspe Peninsula is described from observations made during the summer of 1933 and 1934. This species generally breeds on trees killed by Dendroctonus piceaperda Hopk. but was also found on white spruce dying from the attacks of Diprion polytomum Hartig. In the Gaspe peninsula there is one complete generation a year. At the end of September and the beginning of October, the young adults leave their host tree to hibernate in the ground. Emergence from the ground occurs in the spring.Experiments show that the adult stage lasts nearly two years. During their first complete summer as adults, the females lay two sets of eggs. The following spring they lay a third set and die during the summer. There are one to four egg tunnels per engraving. The average number of eggs per egg tunnel decreases with the increase in the number of females per engraving. Dissection of 500 beetles indicates that the two sexes are present in about equal proportions. Analysis of the results of a po...
TL;DR: In this article, the condensation of propionaldehyde, isobutyraldehyde and trimethylacetaldehyde with glycerol has been carried out in the presence of a catalyst (40% sulphuric acid) at 90 °C.
Abstract: The condensation of propionaldehyde, isobutyraldehyde, trimethylacetaldehyde and dibromoacetaldehyde with glycerol has been carried out in the presence of a catalyst (40% sulphuric acid) at 90 °C.,...
TL;DR: The conclusion that gross chromosome irregularities commonly found in tumor cells cannot in themselves be the cause of cancer, though they may be associated with cancer, is concluded.
Abstract: Significant differences have been found in the spermatocyte chiasma frequencies of ten strains of mice differing in genetic susceptibility or resistance to the spontaneous occurrence of malignant tumors. In three resistant and five susceptible strains there is a positive correlation between susceptibility and low chiasma frequency, and between resistance and high frequency. Two interrelated strains may be exceptional, but their cancer and leukemia records are not clearly established, and one of them, though classed as resistant, is somewhat anomalous genetically.The study comprises a total of 16 tests, each made on 25 complete cells. It was made as an indirect test of a working hypothesis on the mechanism of genetic susceptibility. This hypothesis is based on: (a) the assumed validity of the somatic cell mutation theory of cancer in its most general formulation, (b) the conclusion that gross chromosome irregularities commonly found in tumor cells cannot in themselves be the cause of cancer, though they ma...
TL;DR: A Chytrideaceous parasite apparently not hitherto described has been found on the roots of wheat seedlings grown in soil from Ottawa, Ontario; and Boston, Massachusetts and is considered to be a new species.
Abstract: A Chytrideaceous parasite apparently not hitherto described has been found on the roots of wheat seedlings grown in soil from Ottawa, Ontario; and Boston, Massachusetts. The fungus is closely related to the uniporous Rhizophidiums but since it does not appear to be identical with any of these morphologically and exhibits a type of sexuality not previously described in this genus it is considered to be a new species. The name Rhizophidium graminis is proposed.
TL;DR: Bromine is an invariable constituent of marine algae, but no definite relation appears to exist between their bromine and iodine contents.
Abstract: A number of recent methods for the estimation of bromine in plant and animal tissues have been tested. A combination of the methods of Francis and Harvey (34) and of Yates (98), with some modificat...
TL;DR: In this paper, ten alkaloids have been isolated from Corydalis scouleri, of which the following five are known: protopine (0.47%), cryptopine, bicuculline, corlumine (trace), and Scoulerine, and three non-phenolic alkaloid, all of which appear to be new, were isolated.
Abstract: Ten alkaloids have been isolated from this plant, of which the following five are known:— protopine (0.47%), cryptopine (trace), bicuculline (0.10%), corlumine (trace), and scoulerine (trace). Alkaloid-θ, previously found only in Corydalis scouleri, was present in traces. In addition, three non-phenolic alkaloids, all of which appear to be new, have been isolated, namely: -κ, C19H17O5N∙CH3OH(?), -λ, C19H19O5N, and -μ, C18H17O5N, the latter two containing two methoxyl groups each. Finally a phenolic alkaloid, -ι, C21H21O4N, containing one methoxyl group, is present in minute amounts.
TL;DR: In this article, chemical analyses carried out at five stages of development of Reward and Red Bobs wheat grown on the black and the gray soils of Alberta showed that differences in soil and variety significantly impact the quality of the resulting wheat.
Abstract: Chemical analyses carried out at five stages of development of Reward and Red Bobs wheat grown on the black and the gray soils of Alberta showed that differences in soil and variety significantly i...