bluuebunny/crossref_metadata_2025 huggingface dataset:
THE MEMBRANE SYSTEM OF STREPTOMYCES CINNAMONENSIS
Authors: Chen Pearl Liu
Published: January 2018

The plasma membrane bounding the cytoplasm immediately inside the hyphal wall of Streptomyces cinnamonensis may not retract from the hyphal wall. When it does retract from the wall, it appears as a single dark line in some sections and as 2 dark lines separated by a light zone in others. The membrane system consists of mesosomes and endomembrane structures. The mesosomes are those membrane structures whose derivatives appear to be the plasma membrane. The endomembrane structures, in the present report, are those that appear to have been derived from either the cytoplasm or the limiting membranes of the pre‐existing membrane structures. All membranes seem capable of proliferation, a mechanism obviously responsible for the growth of the individual membrane structures and for the origin of many new ones. The mesosomes, according to their limits, are of 2 distinct types, the open mesosomes and the closed mesosomes. The open mesosomes are partially enclosed by limiting membranes, leaving the unenclosed sides limited by the wall. These mesosomes, when old, usually in aerial hyphae, may become attached to the wall and somewhat deleted from their limiting membranes. The individual membranes in their interior may appear disfigured. The closed mesosomes are completely surrounded by the limiting membranes. These mesosomes, as well as endomembrane structures, retain their original positions in the cytoplasm even in the older aerial hyphae, and the membranes in their interior usually remain practically as distinct in the aerial hyphae as they are in the substratal hyphae. New mesosomes and endomembrane structures are being formed continuously as the mycelium develops. The mesosomes, as a rule, occupy more or less the peripheral regions of the cytoplasm, while the endomembrane structures distribute themselves widely in the cytoplasm and also in the nucleoids. The appearance of the unit membranes, being double‐layered (2 dark lines separated by a light line), is not consistent. The membranes as a whole are more resistant to degeneration than the cytoplasm and the nucleoids.
A REVISION OF ARIOCARPUS (CACTACEAE). IV. FORMAL TAXONOMY OF THE SUBGENUS ARIOCARPUS
Authors: Anderson Edward F.
Published: January 2018

This is the second of 2 articles (Nos. III and IV) dealing with the formal taxonomy of Ariocarpus. A description of the genus and a key to the subgenera and species appeared in the third article of the series. This article includes a description, illustrations, a map of authenticated collection sites, citation of common names, a discussion of synonymy and types, and a list of specimens examined of each species in the subgenus Ariocarpus. The accepted species which are discussed are Ariocarpus retusus, A. agavoides, A. trigonus, and A. scapharostrus.
NUCLEAR DIVISION IN ALTERNARIA TENUIS
Authors: Hartmann G. C.
Published: January 2018

A study of the hyphal and conidial nuclei of Alternaria tenuis with the Feulgen nuclear reaction indicates that division is mitotic. Five chromosomes and a spindle apparatus are formed during nuclear division.
BLUE LIGHT IN THE DEVELOPMENT OF FERN GAMETOPHYTES AND ITS INTERACTION WITH FAR‐RED AND RED LIGHT
Authors: Miller John H. , Miller Pauline Monz
Published: January 2018

Two effects of blue light on the development of Onoclea sensibilis spores are demonstrated. Brief irradiation promotes the protonemal or filamentous type of growth, and the rate of filament elongation is greater than in darkness. Longer periods of irradiation induce the formation of 2‐dimensional prothallia. Blue‐light treatments which promote filament elongation interact with elongation‐promoting far‐red light. Far‐red irradiation alone promotes filament elongation to a greater extent than blue light, but a blue‐light irradiation, either following or preceding far‐red treatment, strongly inhibits the far‐red promotion. In darkness, a slow recovery from the blue‐light‐induced loss of sensitivity to far‐red takes place. The recovery may be greatly accelerated by interposing a red‐light treatment between blue and far‐red irradiation.
A SEASONAL STUDY OF THE VEGETATIVE SHOOT APEX OF MYRIOPHYLLUM HETEROPHYLLUM
Authors: England Wayne H. , Tolbert Robert J.
Published: January 2018

The seasonal study of the vegetative shoot apex and its direct derivatives in the dicotyledonous angiosperm Myriophyllum heterophyllum during the production of its 3 leaf types revealed a great similarity in the anatomy of the apex which produced them. The apex consisted of 2 tunica layers and a corpus that varied slightly. The corpus consisted of the corpus initials, the central rib meristem, and the inner layers of the flanking meristem. The work was compared with several works, but in particular with that of Vochting (1872). Vochting worked with another species, M. spicatum, using the terminology of the histogen concept. This work has verified many of Vochting's observations in the light of today's terminology and extends the range of seasonal shoot‐apical studies.
COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. II. PRUNOIDEAE: MADDENIA, PYGEUM; OSMARONIA
Authors: Sterling Clarence
Published: January 2018

A survey of species of the prunoid genera, Maddenia and Pygeum, and of the genus Osmaronia has been made. The ovules of all are pendent, campylotropous, and epitropic. In the prunoids, the ovular supply is intimately connected with a central vascular plexus in the base of the carpel; that plexus is absent from Osmaronia. The prunoid carpels are marked by an extensive degree of fusion among the ovular and wing bundles, by fusion of the sutural margins, by fusion of the 2 integuments of the ovule to a single massive one, and by the presence of 3 or 5 well‐developed bundles in the base. The carpel of Osmaronia also has a strongly fused bipartite ovular supply, separate bundles of which, however, become very much attenuated before reaching the funiculus; it has independent ovular and wing bundles, completely separate carpellary margins, 2 clearly separate integuments in the ovule, and 6 distinctive bundles in the carpel base. At the funiculus, the wing bundle of Osmaronia is connected with the adjoining weak ovular bundle by a well‐developed vascular branch. Various particularities in the morphology of Osmaronia lend support to its segregation into a unique tribe, the Osmaronieae of Rydberg.
CYTOLOGICAL REACTIONS OF NORMAL AND TMV‐INFECTED TOBACCO LEAF CELLS TO ACID AND ALKALINE SOLUTIONS
Authors: Bald J. G. , Solberg R. A.
Published: January 2018

Acid and basic buffer solutions were applied on slides under cover glasses to thin, hand sections of leaf tissue from normal tobacco plants and equivalent plants infected with tobacco mosaic virus (TMV). The effects on living cells were observed and photographed through phase optics. First, reversible changes and, later, irreversible changes were produced in the cells. Movement of the cytoplasm in a cell could be stopped completely and started again by replacing the unfavorable buffer solution with a favorable medium. Of the organelles, plastids became static first, then mitochondria, and lastly spherosomes. Spherosomes often moved actively when all other organelles were still. Translucent virus monolayers, consisting of particles aggregated side by side, provided markers in the parietal cytoplasm of recently infected cells. Mitochondria generally moved across their surface on the side adjacent to the tonoplast, spherosomes across the surface facing the cell wall. Alkaline buffer solution caused little change of texture in nucleus and cytoplasm or change of form in mitochondria. Clear areas appeared in some plastids. The acid buffer emphasized a cytoplasmic network representing flow lines and eliminated many cytoplasmic vesicles; mitochondria became shorter or spherical in outline, grana of chloroplasts more obvious. Virus inclusions, even the fragile monolayers, were not greatly altered until irreversible changes began. In pH 11–treated cells, the final changes included violent bubbling of cytoplasm, and in pH 2.2–treated cells, snapping of flow lines and coagulation of the cytoplasm. In either case, disintegration of cell structure and virus inclusions was rapid.
CHROMOSOME NUMBERS IN COMPOSITAE. IV. AMBROSIEAE
Authors: Payne Willard W. , Raven Peter H. , Kyhos Donald W.
Published: January 2018

New chromosome observations are reported for 30 species and varieties from 4 genera of Ambrosieae: Ambrosia (including Franseria), Diceria, Hymenoclea and Iva. Neither polyploidy nor aneuploidy is known in the genera Dicorea, Hymenoclea or Xanthium. Aneuplcid reduction appears to have played a role in the genome evolution of several species of Iva and Ambrosia. Polyploid species occur in both Iva and Ambrosia and polyploid series exist for at least 5 species or species aggregates of the latter. All available evidence indicates that the primitive chromosome number for the tribe is x = 18, differentiation and speciation having occurred at this level, which is here termed diploid. The group, however, must ultimately have been of polyploid origin from forms with x = 9.
EFFECTS OF AUXIN ON CELL ENLARGEMENT IN FERN GAMETOPHYTES: DEVELOPMENTAL STAGE OF THE CELL AND RESPONSE TO AUXIN
Authors: Miller John H. , Miller Pauline Monz
Published: January 2018

When gametophytes of Onoclea sensibilis are placed on an auxin‐containing medium in darkness, the cells of the plant increase in length and width. Measurements were made to determine the effects of cell age and auxin concentration on the magnitude of the cells’ response. When comparing final size with size before auxin treatment, the youngest cells have the greatest response. However, they also have the greatest endogenous growth. The optimum auxin concentration for increase in length changes with the age of the cells. The greatest length is attained in young cells with an auxin concentration of 10−‐6–10−‐7 m; 10−‐5 m auxin is supraoptimal. The greatest increase in width of the cells is produced by 10−‐5 m auxin, regardless of cell age. The data are believed best to be interpreted as showing an age‐dependent change in the capacity of the cells to respond to auxin.
THE ROLE OF RESERVES IN LEAVES, BRANCHES, STEMS, AND ROOTS ON SHOOT GROWTH OF RED PINE
Authors: Kozlowski Theodore T. , Winget Carl H.
Published: January 2018

By defoliation, girdling, and various combinations of these before the growing season began, the role of foods in old needles, branches, main stems, and roots on shoot growth of 8‐yr‐old red pine (Pinus resinosa) trees was studied in northern Wisconsin. Defoliation and girdling, alone or in combination, reduced shoot growth but defoliation reduced shoot dry weight more than it reduced shoot elongation. Reductions in shoot growth due to treatment were in the following decreasing order: branch girdling + needle removal > girdling at stem base + needle removal > needle removal > branch girdling > base girdling. The old needles were the major source of food for shoot growth and accounted for four‐fifths or more of all shoot growth. The combined reserves in the branches, main stem, and roots accounted for less than 15% of shoot growth. The contribution of reserves from tissues other than old leaves was in the following order: branches > main stem > roots. Defoliation weakened apical dominance relations. In defoliated trees, many secondary axes elongated more than the terminal leader, and secondary axes in lower whorls often grew more than those in upper ones. The data suggest an important role of nutritional factors in correlative growth inhibition.
BOLDIA: A NEW RHODOPHYCEAN GENUS
Authors: Herndon Walter R.
Published: January 2018

Mature thalli of Boldia erythrosiphon gen. et sp. nov. from Big Walker Creek, Giles Co., Va., are hollow, simple, or, rarely, branched tubular cylinders. The plants generally are from 1 to 20 cm in length and 0.1–1.5 cm in diameter, brownish‐red or olivaceous in color, and grow singly or in clusters from a multicellular holdfast. The vegetative portion of the thallus is essentially monostromatic, comprised of isodiametric, or slightly elongate, uninucleate cells with numerous parietal, simple or lobed, ribbon‐like chromatophore segments. Monospores are produced from narrow, branching filaments (derived from vegetative cells) which form a reticulate pattern in the intercellular matrix external to and at the juncture between groups of (usually 2, 4 or 8) vegetative cells. The spores are liberated singly and germinate into short, branched filaments. New plants arise from small, monostromatic discs of branching filaments united in a common matrix which become cushion‐like and ultimately produce saccate thalli. While Boldia shows affinities with certain members of the Bangiales, it cannot be assigned to any of the presently recognized families. Accordingly, it is placed in a new and distinct family, Boldiaceae, distinguished by the unique manner in which asexual spores are produced from filaments derived from vegetative cells, the filaments developing within the intercellular matrix of the thallus, as well as by the parietal chromatophores of the vegetative cells.
THE SEXUAL CYCLE OF NETRIUM DIGITUS
Authors: Biebel Paul
Published: January 2018

The life cycle of 2 varieties ofNetrium digitus,a saccoderm desmid, was studied in pure culture on mineral media.Netrium digitusvar.digitusfrom Indiana is homothallic, andNetrium digitusvar.lamellosumfrom Minnesota is heterothallic. Previous observations by other investigators on the events of the sexual cycle are confirmed and extended. Zygospores of both varieties are formed in the conjugation tube. Fusion of gametic nuclei occurs after the dormant period of zygospores, and meiosis occurs at the time of germination. Conjugation is induced in a reliable manner in both varieties by omitting nitrogen from the medium and by exposing the cultures to the proper conditions of light and temperature. The relationship between photoperiod, nitrogen depletion, and induction of conjugation is discussed.
GROWTH AND ORGANIZED DEVELOPMENT OF CULTURED CELLS. VII. CELLULAR VARIATION
Authors: Blakely L. M. , Steward F. C.
Published: January 2018

Variation in long‐continued cultures of Haplopappus gracilis and Daucus carota has been investigated. A strain of carrot tissue was isolated that grew with a compact habit, in contrast to the highly friable habit of the parent strain. Its dividing cells were arranged quite differently than in the parent strain. Earlier work had shown that Haplopappus cultures could be reversibly altered in their pigmentation and form, by changing the culture medium. This was confirmed, and it was further shown that pronounced changes in nitrogenous compounds also occurred in response to factors in the medium. However, strains of Haplopappus were isolated which differed persistently from the parent strain, even when they were maintained under the same conditions. The variant strains, grown in the same medium, showed differences in their content of nitrogenous compounds. Stock cultures also changed spontaneously with time with respect to their content of nitrogenous substances. Acriflavine, at low concentration, inhibited the growth and formation of colonics by cells plated on nutrient agar, but, by prolonged exposure to sublethal amounts of the drug, resistant strains were isolated. Certain of the spontaneous variant strains were found to differ from each other and from the parent strain in their chromosome complements in ways that are described and to which the observed changes in morphology and metabolism of the cultures may be attributed. The variations that may occur in the free cells in culture are contrasted with the greater uniformity of the cells as they exist in the plant body.
PHOTOSYNTHETIC ACCLIMATION OF PLANTS OF DIVERSE ORIGIN
Authors: MOONEY H. A. , WEST MarDA
Published: January 2018

Plants of 5 species were acclimated for periods of not less than 3 weeks in a desert and subalpine environment. Subsequent measurements of photosynthesis over a range of temperatures indicated both rate modifications and shifts in temperatures of optimal photosynthesis. Plants of all species acclimated in the coldest environment were more efficient in terms of percentage of maximum photosynthetic activity at colder temperatures. Conversely, plants acclimated in the desert environment were more efficient at warmer temperatures.
METABOLISM OF MANNITOL IN HIGHER PLANTS
Authors: Trip P. , Krotkov G. , Nelson C. D.
Published: January 2018

To determine to what extent higher plants can metabolize mannitol‐C14, it was introduced into 26 species belonging to 17 families. Fifteen species respired mannitol as measured by the evolution of C14O2. In several species, including Fraxinus americana and Syringa vulgaris, mannitol was respired at rates comparable to those of fructose and glucose. In others, including Avena sativa, mannitol was respired only slightly. A lag period in the production of C14O2 from mannitol‐C14, which does not occur after offering glucose‐C14 or fructose‐C14, was considered to be due to a slow penetration of mannitol to the site of its metabolism. The first step in the dissimilation of mannitol was shown to be its oxidation to fructose, possibly via phosphorylated intermediates. Mannitol was not found to be a constituent of polysaccharides of Syringa vulgaris.
DOES AUXIN INHIBIT THE ABSCISSION OF COLEUS LEAVES BY ACTING AS A GROWTH HORMONE?
Authors: Jacobs W. P. , Kaushik M. P. , Rochmis P. G.
Published: January 2018

The hypothesis that auxin prevents abscission, in Coleus blumei, by causing growth has been confirmed in a number of different ways: (1) in the intact plant, petioles grow until just before abscission; (2) excising the blades causes uniformly fast abscission, which is correlated with uniform absence of elongation; (3) if one stimulates the debladed petioles to renewed growth by substituting IAA for the leaf‐blades, one can restore their longevity to that of the intact leaves; (4) increasing the concentration of IAA added to debladed petioles increases both the elongation and the longevity. However, the parallel between elongation and longevity was not exact: IAA concentrations giving full replacement of the blades in preventing abscission gave less than full replacement of elongation in petioles 2 and 3 and more than full replacement in petioles 5–8. Following the time‐course revealed that if an IAA‐treated debladed petiole elongates as much or more than normal during the first week after deblading, then it will have normal longevity.
HETEROTROPHISM AND SPECIES CONCEPTS IN BEGGIATOA
Authors: Pringsheim E. G.
Published: January 2018

From a variety of localities 14 strains of Beggiatoa, 1 ¼–3μ wide, were isolated in axenic heterotrophic culture. Most of these were freshwater forms, 2 were from brackish water, 1 was marine. The widths of the individual strains were constant, independent of conditions. The nutritional requirements of most of the strains are simple. Acetate at low concentrations, an ammonium salt as nitrogen source and the usual inorganic salts including trace elements supported growth. A few strains did not grow well without addition of an amino acid, and 2 (identical) strains required peptone or beef extract. Lactate, succinate, or pyruvate could often replace acetate. Multiplication was in most cases also possible with amino acids alone, without a further organic substrate. The appearance of the various strains on agar plates differs characteristically. Two types could be discerned: one forms spirals and one grows in tongues. These 2 types are not homogeneous for there are within them differences in width, growth rate, nutrition, and salt tolerance, so that a considerable number of independent forms exist even within the narrow limits in width of trichomes to which the investigations were restricted.
THE NATURE OF PLASMODESMATA IN NORMAL (LIVING) PLANT TISSUE
Authors: Livingston Luzern G.
Published: January 2018

Techniques have been devised for the demonstration and study of plasmodesmata in an unaltered state in plant tissues. Text figures and data are presented for plasmodesmata in the cambium and certain other tissues of Pinus strobus, parenchyma tissues of Lycopersicum esculentum, and ray and wood parenchyma tissue of Sequoia sempervirens. In all cases, the plasmodesmata were of similar morphology, with a diameter of approximately 0.2μ. Comparative studies are presented showing the effects of various swelling agents which were used in past studies, and of dehydration which is a normal concomitant of most histological procedures. The present paper provides an important base line for the comparison of the appearance of plasmodesmata in living tissue to the findings of recent studies with the electron microscope.
A NEW MIDDLE PENNSYLVANIAN FOSSIL FUNGUS
Authors: Batra Lekh R. , Segal Ronald H. , Baxter Robert W.
Published: January 2018

The description of Protoascon missouriensis is based on fossil ascosporic fungus with an ostiolate, perithecium‐like fruiting body attached to a vesicular, appendiculate base. Ten or, rarely, 11 unbranched, septate appendages arise from the base, run parallel to each other and envelop the fruiting body. Protoascon resembles some species of Mycocarpon Hutchinson, another fossil fungus, in having a central body containing sporelike structures. The former fungus, however, neither possesses an ostiole nor anything comparable to an appendiculate base. Also, the wall of the fruiting body in Protoascon is apparently 1 cell thick, while it is 1–several cells thick in Myccea. pon. Protoascon was found in a coal ball of the Cabaniss formation, Cherokee group, Desmoinesian stage of the Middle Pennsylvanian system of Missouri, U.S.A.
SPINE DISTRIBUTION IN SEVERAL SCENEDESMUS CULTURES
Authors: Trainor Francis R.
Published: January 2018

In a comparative study of several cultures of species of Scenedesmus, it was determined that some were morphologically quite stable. These included 1 culture each of S. abundans, S. bijugatus and S. quadricauda. Three isolates were pleomorphic. In an axenic culture of one of the pleomorphic organisms one can find coenobia which resemble S. longus, S. abundans, S. bijugatus and S. acutiformis. The value of pure‐culture studies is emphasized, and the identification of members of the genus based solely upon microscopic observation of organisms from nature is discouraged.
THE CHEMICAL REGULATION OF THE DORMANCY PHASES OF BUD DEVELOPMENT
Authors: Smith Harry , Kefford N. P.
Published: January 2018

literature pertaining to the development and regulation of dormancy in the buds of woody species is reviewed and interpreted as follows. Morphological observations, the effects of environmental factors, and other evidence support the concept that bud dormancy involves a cycle of 3 separate phases of development. Beginning at the developmental pattern of spring, the 3 phases are: (1) dormancy development leading to the dormant state; (2) release from dormancy leading to the non‐dormant state; and (3) the initiation of spring burst leading again to spring development. The regulation of dormancy is, therefore, discussed in terms of the regulation of development of the apex within each phase and the regulation of transitions between phases. The principal existing theory of dormancy regulation implies that dormancy consists, in total, of merely the inhibition of spring development, and that regulation involves first the accumulation of an inhibitor then its disappearance. The conceptual basis of this inhibitor theory is argued to be inadequate as is the experimental evidence for the existence of a specific inhibitor and for a correlation between its concentration and dormancy induction or release. There is little direct evidence on the mechanism of the regulation of bud development within any developmental phase. Circumstantial evidence suggests the developmental patterns arise from chemical patterns resulting from the interactions of classes of growth regulator such as auxin, kinin, and gibberellin. Some evidence exists concerning the regulation of the transitions between the phases of dormancy. A substance has recently been detected which may be a hormone regulating the initiation of dormancy development. The production of this substance may be photoperiodically determined. A role for gibberellins in the regulation of dormancy release has been postulated.
INFERIOR OVARY AND GENERIC AFFINITIES OF GARRYA
Authors: Eyde Richard H.
Published: January 2018

Characters of the inflorescence and flower distinguish 2 sections in Garrya. Female flowers of sect. Garrya bear 2 small epigynous appendages, usually considered a rudimentary perianth. In sect. Fadyenia, female flowers are nude, but occasionally 2 more or less foliaceous bracts are partially adnate to the ovary, sometimes simulating the appearance of appendages in sect. Garrya. Authors who have observed this infer that the adnate bracts are homologous to epigynous appendages in sect. Garrya and that the ovary, therefore, cannot be considered inferior. This inference, if valid, would weigh against a close relationship between Garrya and Cornaceae. Clearing and sectioning show, however, that the vascular pattern in flowers of sect. Garrya is similar to the pattern in many Cornaceae. Perianth bundles are united with ventral carpellaries for most of their length, whereas bundles of the adnate bracts in sect. Fadyenia are associated with dorsal carpellary strands; therefore, the 2 kinds of appendages are not homologous. In gynoecial characters Garrya most closely resembles Griselinia and, to a lesser extent, A ucuba. These 3 genera probably had a common origin within the Cornaceae.
TRANSPIRATION FROM THE SPOROPHORE OF AGARICUS BISPORUS ‘WHITE’
Authors: Antonio James P. San , Flegg Peter B.
Published: January 2018

The transpiration from normal, intact, growing sporophores of the cultivated mushroom, Agaricus bisporus cv ‘White’ was determined by a gravimetric method. A simple method was devised to estimate the surface area of a sporophore. Under different conditions of temperature and relative humidity, the quotient of transpiration/cm2 sporophore surface area and evaporation/cm2 free‐water surface area did not significantly differ from 1. Transpiration from the underside of an open‐veil mushroom was related to the planar area rather than to the total exposed gill area. Normally growing sporophores transpired up to 3 mg/cm2/hr. It was estimated that during development to the open‐veil stage, a sporophore transpired a quantity of water equal to ca. one‐half of its fresh weight. There was no evidence of factors other than environmental affecting the evaporation of water from the surface of the normally growing sporophore. Our data were not extensive enough, however, to provide evidence for or against Schütte's hypothesis that transpiration in a mature agaric fructification may be intimately linked with a physiological process.
CHROMOSOME NUMBERS IN CENCHRUS (GRAMINEAE)
Authors: DeLisle Donald G.
Published: January 2018

Gametic chromosome numbers are reported for 22 populations representing 6 taxa in the genus Cenchrus. Numbers of n = 17 were obtained for C. incertus M. A. Curtis, C. longispinus (Hack.) Fern., and for the previously unreported C. mitis Anderss. Populations of C. echinatus L. have the number n = 34, and C. myosuroides H.B.K. n = 35. Irregular meiosis was observed in 2 chromosomal races of C. ciliaris L. having numbers of n = 18 and n = ca. 16, respectively.
THE AMINO ACIDS OF SOME MISTLETOES AND THEIR HOSTS
Authors: Greenham C. G. , Leonard O. A.
Published: January 2018

The following mistletoes and their hosts were studied: Phoradendron serotinum (Raf.) M. C. Johnst. (P. flavescens [Pursh] Nutt. var. macrophyllum Engelm.) on Juglans hindsii Jeps. (California black walnut), Arceuthobium campylopodum Engelmn. f. abietinum (Engelm.) Gill on Abies concolor (Gord. and Glend.) Lindl. (white fir) and A. magnifica A. Murr (red fir), Arceuthobium campylopodum Engelm. f. campylopodum (Engelm.) Gill on Pinus sabiniana Dougl. (Digger pine), and Amyema pendula (Spleng) Tiegh. on Eucalyptus macrorhyncha F. Muell. ex Benth. (stringybark). With the exception of the Amyema leaves, the mistletoes are richer in free and bound amino acids than their hosts; moreover, their amino acid composition closely resembles that of their hosts. Nevertheless, there is no satisfactory evidence that mistletoe specificity depends on the amino acid composition of the hosts. Some mistletoes contain γ‐aminobutyric acid and asparagine, not found in all hosts. All the above mistletoes but no hosts contain free hydroxyproline. These results are discussed in relation to (1) the region in the mistletoes where hydroxyproline is formed and (2) the possibility of using certain amino acid analogs as selective poisons for mistletoes.
COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. IV. POMOIDEAE: CHAMAEMELES, COTONEASTER, DICHOTOMANTHES, PYRACANTHA
Authors: Sterling Clarence
Published: January 2018

The carpels of Chamaemeles, Cotoneaster, Dichotomanthes, and Pyracantha tend to be separate from one another, their sutures tend to be closed, and they become more or less bony at maturity. However, aside from having collaterally placed ovules, they do not appear to be structurally similar. There seem to be 2 different evolutionary trends in the ovular bundle–wing bundle relationship: in Pyracantha, progressive fusion between the ovular bundle and the wing bundle has led to the formation of a “ventral” bundle; in Cotoneaster, and possibly Chamaemeles, the wing bundle has become reduced and rather attenuated. A primitive pomoid state may be represented by the carpel of Dichotomanthes, which is completely free of the floral cup and in which wing and ovular bundles are separate. Differences in sutural closure appear only in Cotoneaster, and in species of that genus the wing bundles and ovular bundles tend to be fused if the suture is closed, and separate if it is open.
THE ABSORPTION AND TRANSLOCATION OF C14‐LABELED PROTEINS IN YOUNG TOMATO PLANTS
Authors: Ulrich Jane M. , McLaren A. D.
Published: January 2018

The uptake of C14‐labeled proteins (lysozyme, hemoglobin, lactoglobulin, and ovalbumin) from solution by tomato plants with sterile roots was studied. It was found that C14‐compounds (proteins and/or protein‐degradation products) were translocated to the foliage if the roots had undergone minor mechanical injury or if the plants were subjected to temporary wilting, i.e., physiological damage. C14‐lysozyme was not transported to foliar tissue in healthy plants; C14‐hemoglobin showed radioactivity in leaves of both healthy and injured plants, but there was evidence of a breakdown of the molecule; C14‐ovalbumin gave a faint labeling of foliar tissues of some plants in which wilting or mechanical damage was below the threshold of detection. It is concluded, however, that translocation of proteins from roots in nutrient solution to tomato leaves does not occur in significant amounts in healthy plants in spite of the large uptake of proteins by root cortex, as found in earlier studies.
PHENYLBORIC ACID, A CHEMICAL AGENT SIMULATING THE EFFECT OF THE LANCEOLATE GENE IN THE TOMATO
Authors: Mathan David S.
Published: January 2018

Lanceolate, a spontaneously occurring mutant in the tomato, which has 1 dosage of the mutant gene, causes a change in the shape of the leaf from the odd‐pinnately compound leaf characteristic of the normal tomato plant to a simple, much‐reduced in size lanceolate leaf. Homozygous mutant plants, which have 2 dosages of the mutant gene, exhibit extreme lanceolate features, producing a simple narrow leaf, similar in shape to the lanceolate leaf but much smaller in size. The mutant allele of the lanceolate gene causes, in addition to the change in leaf form, the increase in activities of the following oxidative enzymes: tyrosinase, laccase, peroxidase and catalase. The lanceolate gene exhibits a dosage effect with respect to these enzymes, homozygous lanceolate showing the highest activity; heterozygous lanceolate, an intermediate; and normal, the lowest activity. Treatment of germinating normal tomato seeds with phenylboric acid simulated the effect of the mutant allele of the lanceolate gene with regard to both the induction of a lanceolate leaf and the increase in the activity of the above 4 oxidative enzymes; phenylboric acid treatment resulted in relatively higher increase in the activities of the oxidative enzymes in normal and heterozygous lanceolate than in homozygous lanceolate. A direct and close relationship existed between the shape of the leaf and the activity of the enzymes during leaf development. It is suggested that the mutant allele of the lanceolate gene, as well as phenylboric acid, induces an increase in activity of the oxidative enzymes and that this increase in enzyme activities brings about the orderly change in form.
THE WHEAT GRAIN DURING DEVELOPMENT WITH REFERENCE TO NATURE, LOCATION, AND ROLE OF ITS TRANSLOCATORY TISSUES
Authors: Frazier John C. , Appalanaidu B.
Published: January 2018

The structure of the crease region of the developing wheat grain was studied with reference to the nature and role of its tissues. The vascular bundle, which extends from base to apex at the bottom of the furrow (crease), and the chalaza and nucellar projection, which lie between the bundle and the endosperm, were also studied. It was established that nutrient substances move through these 3 tissues into the endosperm of the developing kernel. The time of such movement was studied. Findings of this study were correlated with those of other investigators.
NUCLEOLAR VARIATION DURING DIFFERENTIATION OF PHLEUM ROOT EPIDERMIS
Authors: Lowary Patricia A. , Avers Charlotte J.
Published: January 2018

Striking differences in nucleolar volume were found between trichoblasts and hairless initials all along the differentiation gradient of the tissue. The larger nucleoli of the trichoblasts were evident from the onset of their differentiation in the meristem and remained so throughout the growing 1000μ of epidermis. At the same time, nucleoli of the alternating, hairless initials rapidly became reduced in volume and virtually disappeared in maturing cells. Nuclear volume was relatively constant throughout the epidermis, so that nuclear:nucleolar volume ratios clearly indicated the nucleolar differences between the shorter trichoblasts and longer hairless initials. Along with the first signs of nucleolar volume difference in the meristem, there were higher concentrations of RNA and ribonucleoprotein in nucleoli and cytoplasm of trichoblasts compared with hairless initials. Although these chemical differences occurred principally in meristem cells, protein content was much higher in trichoblasts than in the alternating hairless initials of the enlargement zone, 300–500μ from the root tip apex. There was no essential difference in protein content between the 2 cell types in the meristem or in older enlarging cells. The data suggested that the initial increase in nucleolar volume and content of the meristem trichoblasts led to their increased protein content and enzyme activities during the enlargement phase of their differentiation. The sharp reduction in nucleoli of the hairless initials, at the same time, led to their generally lower metabolism during tissue differentiation.
FLORAL PIGMENTATION STUDIES IN THE GENUS GOSSYPIUM. I. SPECIES SPECIFIC PIGMENTATION PATTERNS
Authors: Parks Clifford R.
Published: January 2018

Previous work on cotton flower pigments is outlined. The major flavonoids are glycosides of gossypetin, quercetin, and kampferol. Twelve flavonol glycosides have been tentatively isolated and identified, while a number of minor components remain unidentified. The gossypetin glycosides are gossypin, gossypitrin and a C7‐linked glycoside of unknown sugar residue. The quercetin glycosides include isoquercitrin, rutin, a third C3‐linked glycoside with unknown sugar residue, quercimeritrin and a second C7‐linked glycoside with sugar residue unknown. The kampferol glycosides include trifolin, kampferol rutinoside and 2 other C3‐linked glycosides with unknown sugar residues. The major anthocyanin throughout the genus is cyanidin. Mutants which affect visible flower color were studied in 3 species (G. arboreum, G. hirsutum, and G. barbadense). The majority of these mutants act to decrease or prevent the synthesis of gossypetin glycosides. The only exceptions to this are the mutants at the Ya locus in G. arboreum, which affect all of the C7‐linked glycosides in one case, and in the other reduce over‐all flavonol production. In all instances, the species could be positively identified by the residual array of pigments not affected by the mutant alleles concerned; i.e., visual similarity of phenotypes did not obscure the basic pattern of pigmentation characteristic of the different species.
FUNGAL GEL TISSUE ONTOGENESIS
Authors: Moore Elizabeth J.
Published: January 2018

Conspicuous gelatinous tissues, consisting of gel and hyphae, occur in fungi in the discomycete subfamilies Ombrophiloideae and Leotioideae and in the basidiomycete order Tremellales. The origin and subsequent development of gelatinous tissues in representative species were investigated. Fungal gels may be selectively stained with the mucin stain, mucicarmine, and metachromatically with toluidine blue. Gel was found to arise in 2 fundamentally different ways, by hyphal disintegration and by direct secretion of mucilage from the protoplasm. With hyphal disintegration a swelling of the hyphal walls may precede the formation of the gel, as occurs in the conidiophores ofCoryne cylichnium,or the hyphae may disintegrate directly to form the gel, as occurs in the basidiocarp ofPseudohydnum gelatinosum.Mucilage secretion occurs in the discomycetesBulgaria inquinans, Coryne cylichnium, Corynellasp.,Cudonia lutea, Holwaya leptosperma, Leotia viscosa, Neobulgaria pura,andNeobulgariasp. Mucilage is secreted directly from the hyphae, except in the imperfect stage ofH. leptospermain which specialized secretory cells occur. Deeply staining material aggregates in the hypha or cell and is then extruded through small pores in the walls. A subsequent change in viscosity occurs and the mucilage becomes gelatinous. If produced in small amounts, the gel ensheaths the hyphae and collects in the interhypbal spaces in a loosely organized tissue, or forms interstitial gel in a compactly organized tissue. If gel is produced in large amounts it will form a continuous gel matrix regardless of the tissue type. Sites of unusually heavy gel production (here termed “gliatopes”) may be formed in either rapidly developing or confined tissue. Both mucilage secretion and hyphal disintegration to form gel occur in the cupulate coremium of the imperfect stage ofC. cylichnium.
THE INDUCTION OF LEAF TUMORS BY AGROBACTERIUM TUMEFACIENS
Authors: Lippincott James A. , Heberlein Gary T.
Published: January 2018

Using carborundum as an abrasive and light rubbing with a culture of Agrobacterium tumefaciens, leaves of various species of bean and tobacco develop tumors on the leaf lamina. The induction of these tumors requires wounding, the presence of a virulent strain of the bacterium and is due to the bacterium, not substances released into the bacterial culture medium during growth. Observations of the histology and cytology of these tumors on the primary leaves of pinto bean show no significant differences from the more commonly studied stem tumors. The tumors on pinto beans first appear as chlorotic nests of dividing cells which gradually accumulate chlorophyll, eventually becoming dark green in color as opposed to the surrounding leaf tissue which is completely chlorotic at this stage. Tumor development is enhanced by a dark period following inoculation while growth of the leaf is essentially stopped. The tumors thus exhibit a pattern of growth and development independent of that of the normal leaf. The number of tumors obtained on pinto bean leaves was found to depend on the concentration of bacteria in the inoculum and on the age of the plants. A sharp peak in response was observed at about 7 days from planting. Best results were obtained by adding the bacterium at the time of wounding. The tumors were shown to differ from IAA‐induced leaf proliferations with respect to their point of origin on the leaf, morphology, physiology and development.
THE RESPONSE OF MALE GAMETES OF ALLOMYCES TO THE SEXUAL HORMONE SIRENIN
Authors: Carlile M. J. , Machlis Leonard
Published: January 2018

Attraction of male gametes of Allomyces to sirenin concentrations as low as 10−‐10 m has been demonstrated. Increasingly strong responses are observed to concentrations up to 10−‐6 m. The response is slightly weaker at 10−‐5 m and very weak at 10−‐4 m. Microscopic studies suggest that the attraction comes into the category of tropotaxis, a direct approach to a sirenin source occurring. Male gametes have been shown to inactivate sirenin. The possibility that this inactivation is an adaptation process enabling the gametes to maintain sirenin sensitivity over a 100,000‐fold concentration range is discussed.
ASSOCIATION OF THE ENDOPLASMIC RETICULUM AND THE PLASTIDS IN ACER AND PINUS
Authors: Wooding F. B. P. , Nokthcote D. H.
Published: January 2018

A close sheathing of the plastids by endoplasmic reticulum has been observed. This is restricted to the companion cells and developing sieve tubes of the phloem of Acer pseudoplatanus and the resin canal cells and leaf callus cells from Pinus pinea. The sheathing is transitory in callus and sieve tubes but is a permanent feature of the companion and the resin canal cells. Possible functional relationships between the two organelles are discussed.
THE INDUCTION OF FLOWERING IN NICOTIANA. III. VARIATIONS IN THE LEVEL OF ENDOGENOUS GROWTH SUBSTANCES
Authors: Nitsch J. P. , Nitsch C.
Published: January 2018

A chromatographic investigation of the native growth substances active on the Avena first‐internode test has shown the existence of at least five different peaks of activity in methanolic extracts of a short‐day and a long‐day Nicotiana, N. tabacum cultivar ‘Maryland Mammoth’ and N. sylvestris. Some of these substances are active on the dwarf‐maize test for gibberellins. The levels of the various substances have been determined in the adult leaf, the immature leaf, and the tip of the shoot. Their variations have been followed during the shifting of the plants from a noninductive to an inductive photoperiod in relation to the transition of the terminal apex from the vegetative to the reproductive state.
GROWTH OF EXCISED PINE EMBRYOS AND THE ROLE OF THE COTYLEDONS DURING GERMINATION IN VITRO
Authors: Berlyn Geaeme P. , Miksche Jerome P.
Published: January 2018

A study was made of the role of the cotyledons, embryo orientation, surgical treatment, darkness, light, and autoclaved coconut milk on the growth of Pinus lambertiana Dougl. embryos in vitro. The embryos did not require an haustorial function of the cotyledons in vitro. Removal of the shoot meristem drastically altered the developmental physiology of the embryo and the function of the root meristem was severly inhibited. Positional effects on embryo growth were reversed by darkness. In the light vertical‐inverted tube cultures displayed better growth than horizontal‐inverted tube cultures, whereas in the dark the horizontal‐inverted tube cultures displayed better growth than the ver ical‐inverted tube cultures. Autoclaved coconut milk had no statistically demonstrable effect on embryo growth as measun d by the analysis of variance and Student‐Newman‐Keul's range test; however, the graphical analysis suggests that, in conjunction with the presence of the shoot meristem, there may be a slight beneficial response to autoclaved coconut milk.
A NEW SPECIES OF SYNCEPHALIS (MUCORALES)
Authors: Embree Robert W.
Published: January 2018

Syncephalis plumigaleata sp. nov. is distinguished from other species by the unilateral placement of the merosporangia on the apical sporangiophore vesicle.
CARBONYL COMPOUNDS PRODUCED BY CERATOCYSTIS FAGACEARUM
Authors: Collins R. P. , Kalnins K.
Published: January 2018

Ceratocystis fagacearum produces both in nature and in laboratory culture a characteristic fruity aroma. It is assumed that the odor may serve as an attractant for insects which are vectors for the disease as well as important agents in the fertilization mechanism. A number of carbonyl compounds were identified from liquid cultures of C. fagacearum and included: acetaldehyde, furfuraldehyde, acetone, 2‐hexenal and 2‐methylbutanal. The 2,4‐dinitrophenylhydrazones of the compounds were identified by means of thin‐layer chromatography, melting‐point determination, gas chromatography and infrared spectroscopy.
HISTOGENESIS OF LEAF VENATION IN TRIFOLIUM WORMSKIOLDII (LEGUMINOSAE)
Authors: Lersten Nels
Published: January 2018

The histogenesis of the leaf venation in Trifolium wormskioldii was followed, using whole cleared leaflets and transverse and paradermal microtome sections. Mature leaflets are about 8 mm in length. The midvein precambium appears in leaflets 100 μ in length; secondary vein procambium is first seen in 230 μ leaflets; procambium of minor veins first appears in leaflets 400‐600 μ in length. Phloem is apparent before xylem, in midvein, secondary veins, and minor veins. Vein endings are initiated and they mature last. No evidence was found to support the theory of “vein breakage.” In the greenhouse 24 days elapsed from leaf initiation to exposure of leaf tips; 6 more days elapsed until full leaf expansion.
THE QUANTITATIVE DETERMINATION OF THE INFECTIVITY OF AGROBACTERIUM TUMEFACIENS
Authors: Lippincott James A. , Heberlein Gary T.
Published: January 2018

A bioassay relating number of Agrobacterium tumefaciens cells in the inoculum quantitatively to the number of crown‐gall tumors initiated on primary pinto bean leaves is described. Variability in estimation of infectious titers by this assay is similar to that observed in comparable plant virus assays, most determinations showing standard errors of 20% of the mean tumor per leaf value. The assay has the advantages of speed and practicality. The efficiency of the system is low, typically requiring between 105 and 106 bacteria for each tumor initiated. Infectivity titers of 103‐104, however, are readily obtained from stationary phase cultures. Statistical analysis of the infectivity titration curve indicates that a single bacterium is the usual infectious unit. The assay is specific within the family Rhizobiaceae to the species Agrobacterium tumefaciens and Agrobacterium rubi. A. tumefaciens strains IIBNV6 and ATCC # 11095 were non‐infectious, while strain B6 was the most infectious of the strains tested. The infectivity of the latter strain is shown to decrease about 4‐fold between early log and stationary phases of growth. Changes in the growth medium or in the dilution‐inoculation medium failed to alter the infectivity of the bacterium.
THE RELATIONSHIP BETWEEN THE PROMOTION OF ELONGATION OF FERN PROTONEMATA BY LIGHT AND GROWTH SUBSTANCES
Authors: Miller John H. , Miller Pauline Monz
Published: January 2018

Germinating spores of the fern Onoclea sensibilis L. were grown in darkness, so that they developed as filaments (protonemata). Brief daily exposure of the filaments to red, far‐red or blue light increased the rate of filament elongation. Filament elongation was also promoted by indoleacetic acid. When filament elongation was promoted with both indoleacetic acid and exposure to light, the growth promotions caused by red and far‐red light were additive to auxin‐induced growth. Blue light promoted elongation only at sub‐optimal concentrations of auxin. Elongation induced by guanine was additive to red‐ and far‐red‐induced elongation. Gibberellic acid had no effect on elongation under any condition. Blue‐light‐induced elongation resembled auxin‐induced elongation in its requirement for exogenous sucrose and sensitivity to inhibition by parachlorophenoxyisobutyric acid. Red and far‐red light were active regardless of the presence or absence of sucrose and promoted elongation at a concentration of parachlorophenoxyisobutyric acid which completely inhibited blue‐light‐induced elongation.