bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECTS OF DARKNESS AND OF STREPTOMYCIN ON THE FINE STRUCTURE OF EUGLENA GRACILIS
Authors: Siegesmund Kenneth A. , Rosen Walter G. , Gawlik Stanley R.
Published: January 2018

Siegesmund, Kenneth A., Walter G. Rosen, and Stanley R. Gawlik. (Marquette (J., Milwaukee, Wis.) Effects of darkness and of streptomycin on the fine structure of Euglena gracilis. Amer. Jour. Bot. 49 (2) : 137–145. Illus. 1962.—Dark‐grown Euglena gracilis cells, transferred from streptomycin (SM)‐containing medium to SM‐free medium 5 days before transfer to light, turn green normally, indicating that proplastids are unaffected by SM. SM‐bleached cells, grown in light, contain numerous bodies composed of concentric lamellae (CL bodies). These differ from chloroplasts in that their lamellae lack electron‐dense dots, are not coalesced, and they lack a 3‐layered limiting membrane and pyrenoids. CL bodies are absent from dark‐grown normal and dark‐grown SM‐bleached cells, as well as from light‐grown normal cells. It is suggested that CL bodies result from a derangement of chloroplast synthesis caused by SM blockage of chlorophyll synthesis.
REAPPRAISAL OF UTRICULARIA INFLATA AND U. RADIATA (LENTIBULARIACEAE)
Authors: Reinert Grady W. , Godfrey R. K.
Published: January 2018

Reinert, Grady, W., and R. K. Godfrey. (Florida State U., Tallahassee.) Reappraisal of Utricularia inflata and U. radiata (Lentibulariaceae). Amer. Jour. Bot. 49(3): 213–220. Illus. 1962.—Utricularia inflata and U. radiata, interpreted either as separate species or 2 varieties of a single species by previous investigators, are shown to be specifically distinct on the basis of 5 hitherto‐neglected, morphological characters, 4 of which are vegetative in nature, and on the basis of 3 reinvestigated quantitative criteria. The particular attention devoted to the vegetative bodies of the 2 plants led to the discovery, in U. inflata, of tuber formation, a phenomenon known to occur in Utricularias in general but unreported for North American species. Support for interpreting U. inflata and U. radiata as species resides in the distribution patterns. Although both occur on the outer coastal plain from southern Alabama to southern Delaware, the 2 taxa are easily distinguishable and exhibit no intergradation. The range of U. radiata is much broader; it extends westward to eastern Texas northeastward to Nova Scotia, and is disjunct inland in western Tennessee, western Virginia and in northwestern Indiana.
THE ROLE OF ZINC IN THE GROWTH OF PLANT TISSUE CULTURES
Authors: Klein Richard M. , Caputo Emerita M. , Witterholt Barbara A.
Published: January 2018

Klein, Richard M., Emerita M. Caputo, and Barbara A. Witterholt. (New York Bot. Gard., N. Y., N. Y.) The role of zinc in the growth of plant tissue cultures. Amer, Jour. Bot. 49(4): 323–327. Illus. 1962.—Zinc‐sufficient and zinc‐deficient auxin‐auxotrophic callus and auxin‐prototrophic crown‐gall cultures of Parthenocissus tricuspidatus were examined for their growth capacity and ability to synthesize tryptophan. Growth capacity decreased rapidly when zinc ion was withheld and tryptophan synthetase activity in vitro was reduced. Growth of –Zn crown‐gall tissues was stimulated by either auxin or tryptophan and growth of –Zn callus cultures was stimulated by tryptophan.
MITOSIS IN SUSPENSION CULTURES OF HIGHER PLANT CELLS IN A SYNTHETIC MEDIUM
Authors: Torrey John G. , Reinert Jakob , Merkel Nancy
Published: January 2018

Torrey, J. G., J. Reinert, and N. Merkel. (Harvard U., Cambridge, Mass.) Mitosis in suspension cultures of higher plant cells in a synthetic medium. Amer. Jour. Bot. 49(4): 420–425. Illus. 1962.—A cytological study was made of plant tissue cultures growing in liquid synthetic medium. Mitoses in cell suspension cultures of root callus tissues of Daucus carota L., Convolvulus arvensis L. and Haplopappus gracilis (Nutt.) Gray were found to occur frequently in the first 2 weeks of culture with the highest frequency at about 7 days. No mitoses were observed after 3 weeks, although fresh weight and the number of free‐floating cells in the suspension continued to increase for the entire culture period of 4–6 weeks. Mitoses were most frequent in tissue pieces, but occasional mitoses in single isolated cells in suspension were observed in each type of tissue. Normal mitoses were observed in diploid and polyploid cells of all 3 types of tissues cultures. Little evidence of nuclear or chromosomal aberrations was observed in these cultures.
MASS CULTURE OF ALGAE FOR FOOD AND OTHER ORGANIC COMPOUNDS
Authors: Krauss Robert W.
Published: January 2018

Krauss, Robert W. (U. Maryland, College Park.) Mass culture of algae for food and other organic compounds. Amer. Jour. Bot. 49(4): 425–435. Illus. 1962.—Data are being collected which appear to support the use of unicellular algae for human food. Analyses of proteins, fats, carbohydrates, and vitamins indicate that unicellular green algae, especially Chlorella, should be excellent sources of these nutrients. The effectiveness of the algae for the support of growth of chickens, mice, rats, and rabbits has been found to be good. However, only limited studies have been done with humans. The problem of acceptability varies with the nationality of the subjects and the preparation of the food. Serious gaps still exist both in the technology of production and in the experimentation required to establish nutritional value. Nutrition studies using algae free of bacteria are urgently needed.
THE BULLER PHENOMENON IN SCHIZOPHYLLUM COMMUNE: NUCLEAR SELECTION IN FULLY COMPATIBLE DIKARYOTIC‐HOMOKARYOTIC MATINGS
Authors: Ellingboe Albert H. , Raper John R.
Published: January 2018

Ellingboe, Albert H., and John R. Raper. (Harvard U., Cambridge, Mass.) The Buller Phenomenon in Schizophyllum commune: nuclear selection in fully compatible dikaryotic‐homokaryotic matings. Amer. Jour. Bot. 49(5): 454–459. 1962.—Internuclear selection in fully compatible, dikaryotic‐homokaryotic matings of isogenic strains is apparently controlled by the incompatibility factors and, in some cases, by extra‐incompatibility factors. The relationship of the structure of the incompatibility factors to internuclear selection is not clear. Both types of nuclei from the dikaryon migrate into the homokaryon, and it appears that selection occurs in the final establishment of the new dikaryon.
GROWTH AND SEXUAL REPRODUCTION OF THE MOSS AMBLYSTEGIUM RIPARIUM UNDER STERILE CONDITIONS
Authors: Belkengren R. O.
Published: January 2018

Belkengren, R. O. (Oregon State U., Corvallis.) Growth and sexual reproduction of the moss Amblystegium riparium under sterile conditions. Amer. Jour. Bot. 49(6): 567–571. Illus. 1962.—Growth of Amblystegium riparium as primary or secondary protonemata, or as a leafy gametophyte under aseptic conditions, is reported. Yeast extract appears to be inhibitory for shoot growth but not for protonemal growth; it appears to cause the death of shoot buds on protonemata before they differentiate into leafy shoots, so that the organism grows as protonema only. Sexual reproduction of this organism in continuously illuminated cultures was induced by a CO2‐free period followed by addition of CO2 or sugar. Senescence in a culture may also induce sporophyte formation presumably by interfering with photosynthesis or some other function.
A VIRUS‐LIKE SYNDROME IN TOMATO CAUSED BY A MUTATION
Authors: Edwardson J. R. , Corbett M. K.
Published: January 2018

Edwardson, J. R., and M. K. Corbett. (Florida Agric. Expt. Sta., Gainesville.) A virus‐like syndrome in tomato caused by a mutation. Amer. Jour. Bot. 49(6): 571–575. Illus. 1962.—A mutation in the ‘Marglobe’ tomato variety, similar in appearance to tomatoes infected with strains of cucumber mosaic virus or tobacco mosaic virus, was found in 1959. The ‘Marglobe’ mutant also closely resembles the phenotypes of the wiry series of tomato mutants in possessing narrow cotyledons, abnormal “wiry” leaves, reduced laminae of leaflets, divided sepals and petals, apocarpous ovaries and a high degree of female sterility. The appearance of the mutant is not attributable to virus infection because none of the mutant characters appeared in stock or scions of reciprocally grafted mutant and normal plants Segregation of the “wiry” phenotype in F2 and backcross populations indicates that the mutant phenotype is controlled by a single pair of recessive genes exhibiting marked pleiotropic effects.
PROTEIN CHANGES DURING MORPHOLOGICAL DIFFERENTIATION AND ITS REVERSAL IN SYNCHRONIZED SINGLE GENERATIONS OF BLASTOCLADIELLA EMERSONII
Authors: Cantino E. C. , Goldstein A.
Published: January 2018

Cantino, E. C., and A. Goldstein. (Michigan State U., East Lansing.) Protein changes during morphological differentiation and its reversal in synchronized single generations of Blastocladiella emersonii. Amer. Jour. Bot. 49(6): 642–646. Illus. 1962.—Part of the soluble protein pool in synchronized, single generations of RS (resistant sporangial) cells of Blastocladiella emersonii at different stages in ontogeny was fractionated on DEAE‐cellulose; morphological differentiation was associated with changes in the quantities per cell of various protein components. The protein pool in RS cells was compared with that in OC (ordinary colorless) cells, the latter being formed via an alternate morphogenetic pathway. Among the separable proteinaceous components, one major fraction in an OC cell was reduced to one third this level in an RS cell; a second fraction increased about 6‐fold, while 5 other components changed very little. It was concluded that the bicarbonate‐induced RS differentiation involves appreciable reorganization of the protein pool. When a young RS cell, which has not reached its morphological point of no return, is made to revert to the alternate morphogenetic path leading to an OC cell, by removing exogenous bicarbonate, the quantitative relationship between certain protein fractions of the cell also reverses and quickly approaches that found in a mature OC cell. Alternatively, beyond the point of no return in RS differentiation, when genesis of an OC cell can no longer be induced by removal of bicarbonate, this alteration of the protein pattern does not occur.
GENETICS OF SORDARIA FIMICOLA. V. ABERRANT SEGREGATION AT THE G LOCUS
Authors: Kitani Y. , Olive L. S. , El‐Ani Arif S.
Published: January 2018

Kitani, Y., L. S. Olive, and Arif S. El‐Ani. (Columbia U., New York City.) Genetics of Sordaria fimicola. V. Aberrant segregation at the g locus. Amer. Jour. Bot. 49(7): 697–706. Illus. 1962.—Aberrant segregation of the gray‐spore color locus in Sordaria fimicola was studied with the aid of closely linked markers. It was found that 6:2 and 5:3 asci occur with about the same frequency, but asci with an excess of wild‐type spores occur with a frequency 5.5 times that of asci with an excess of gray spores. Also, the frequency of related crossing over (occurring close to the miscopied loeus and involving the miscopying strand) was much higher than the expected value, and in 5:3 asci it appears to be at least twice that found in 6:2 asci. Nine aberrant 4:4 asci, each with 2 spore pairs heterogeneous for color, were found. These are believed to have resulted from reciprocal double transreplication. The rarest aberrant type was represented by a single 7:1 ascus, which is difficult to explain on the basis of a single meiotic process. Miscopying is discussed with relation to an 8‐strand model of paired homologues and the occurrence of localized chromosome pairing during prezygotene DNA synthesis. Several possible explanations for the occurrence of aberrant tetrads are considered. Miscopying has also been found to involve several spore‐color loci not previously studied; whereas, several other such mutant loci fail to show evidence of it. One locus (m) shows abnormal segregation of the 6:2 but not the 5:3 type.
ADDITIONAL OBSERVATIONS ON STEPHANOSPERMUM OVOIDES, A MIDDLE PENNSYLVANIAN SEED
Authors: Taylor Thomas N.
Published: January 2018

Taylor, Thomas N. (U. Illinois, Urbana.) Additional observations on Stephanospermum ovoides, a Middle Pennsylvanian seed. Amer. Jour. Bot. 49(7): 794–800. Illus. 1962.—Recently additional specimens of Stephanospermum ovoides have been discovered in coal‐ball material collected at the New Delta Mine, Absher, Williamson County, Illinois. Stephanospermum ovoides is a radially symmetrical ovoid seed, characterized by a low sclerotestal crown and micropylar beak. The species stands intermediate in relation to other members in the genus in its sclerotestal elaboration, which is assumed to be reflected in the size of the crown and mieropylar beak.
THE INHERITANCE OF ACENAPHTHENE TOLERANCE IN NEUROSPORA SITOPHILA
Authors: Whittingham W. F.
Published: January 2018

Whittingham, W. F. (U. Wisconsin, Madison.) The inheritance of acenaphthene tolerance in Neurospora sitophila. Amer. Jour. Bot. 49(8): 866–869. 1962.— Acenaphthene‐tolerant strains of N. sitophila, a species that normally does not grow in the presence of the fungistatic hydrocarbon, were isolated. The growth rates of the tolerant strains were less than those exhibited by the parental cultures, especially when acenaphthene was present in the medium. However, the tolerant character was stable for at least 5 generations and apparently resulted from a single‐gene mutation as judged from mating experiments.
INTERACTION OF IONIZING AND VISIBLE RADIATION IN MUTATION INDUCTION IN NEUROSPORA CRASSA
Authors: Klein Richard M. , Klein Deana T.
Published: January 2018

Klein, Richard M. (New York Bot. Gdn., New York, N.Y.), and Deana T. Klein. Interaction of ionizing and visible radiation in mutation induction in Neurospora crassa. Amer. Jour. Bot. 49(8): 870–874. 1962.—Conidia of the purple adenineless strain of N. crassa were irradiated with 25 kr of X rays and then exposed to far‐red or red radiations or to far‐red followed by red radiation. Far‐red light, without effect on un‐irradiated conidia, augmented the genetic damage caused by X rays as measured by survival (colony count), back mutation to adenine prototrophy, and the induction of mutants affecting colony morphology. Post‐X‐irradiation with red light ameliorated the severity of X‐radiation as measured by survival and back mutation. The potentiation of X‐ray‐induced genetic damage by far‐red light could be completely negated by subsequent exposure to red light.
FINE STRUCTURE STUDIES OF PHLEUM ROOT MERISTEM CELLS. I. MITOCHONDRIA
Authors: Avers Charlotte J.
Published: January 2018

Avers, Charlotte J. (Douglass Coll., Rutgers—The State U., New Brunswick, N.J.) Fine structure studies of Phleum root meristem cells. I. Mitochondria. Amer. Jour. Bot. 49(9): 996–1003. Illus. 1962.—Mitochondrial numbers were computed from thick sections embedded in paraffin and stained with iron hematoxylin, from methacrylate embedded, 0.5 μ‐thick sections stained with osmium, and from electron micrographs of ultrathin sections fixed in KMnO4. The mean mitochondrial counts per average cell (20 × 20 × 10μ) were: 121 ± 4 in paraffin sections, 600 ± 40 in methacrylate sections, and 991 ± 96 from electron micrographs. These numbers were higher than the Janus green B count of 91 ± 2 per cell found during an earlier study. In each case, arithmetical conversion factors were used to calculate total numbers of mitochondria per cell since section thicknesses were less than that of whole cell length or depth. Determinations of numbers of mitochondria probably varied depending on section thickness and specific staining procedures used, but the higher count from electron micrographs was assumed to be reasonable on a volumetric basis. The cytoplasmic volume of the average cell is about 2500 μ3 and the volume of a single average mitochondrion is about 0.1μ3. On this basis, the variety of structures and their relatively sparse distribution seems possible despite the apparently high numbers found. In addition to mitochondria, the numbers of various cellular components per unit cytoplasmic area were determined. These data showed that mitochondria were about 6 times more numerous than proplastids, about 4.5 times more numerous than Golgi bodies, and even more frequent when compared with vesicles, dense bodies, or microbodies. No correlation was found between cytoplasmic area and numbers of organelles per unit area. Photographic evidence was presented for the occurrence in plant cells of the hepatic cell, polymorphic “lysosome” described by Ashford and Porter. The controversial nature of the lysosome is discussed.
THE FINE STRUCTURE OF CHLOROPLASTS FROM MINERAL‐DEFICIENT LEAVES OF PHASEOLUS VULGARIS
Authors: Thomson William W. , Weier T. E.
Published: January 2018

Thomson, W. W., and T. E. Weier. (U. California, Davis.) The fine structure of chloroplasts from mineral‐deficient leaves of Phaseolus vulgaris. Amer. Jour. Bot. 49(10): 1047–1055. Illus. 1962.—An electron microscopic study of the changes in chloroplast structure as affected by the stress of nutrient deficiencies is described. Each deficiency produces characteristic changes in the ultrastructure of the chloroplast. In phosphorus and potassium deficiency the plastids develop fully before changes occur; then the grana break down into diffuse, electron‐dense masses, forming a highly ordered lamellar system. The plastids of plants low in nitrogen and magnesium do not reach full development before changes occur. In nitrogen‐deficient plastids, the stroma is greatly diminished and the grana compartments are swollen and reduced in number. In magnesium deficiency, the grana‐fretwork system becomes disorganized and many star‐bodies are formed. The absence of zinc blocks the full development of a grana‐fretwork system, and large vacuoles are formed in conjunction with grana compartments.
CYTOHISTOLOGICAL STUDIES OF CYTOCHIMERIC AND TETRAPLOID GRAPES
Authors: Thompson Maxine M. , Olmo H. P.
Published: January 2018

Thompson, M. M., and H. P. Olmo. (U. California, Davis.) Cytohistological studies of cytochimeric and tetraploid grapes. Amer. Jour. Bot. 50(9): 901–906. Illus. 1963.—Cytohistological studies were made on 62 different grape clones suspected to be tetraploids to determine if they were chimeras, and if so, what type. The chromosomal constitution of the apical layers in the shoot was determined on the basis of cell and nucleus size, size of chromosome mass, and chromosome estimates or counts. Three cytological types were observed; 2–4,2 4–2, and 4–4. The possible types of chimeras and their stability depend upon the organization of the shoot apex. In most buds there appeared to be a biseriate tunica covering a corpus. However, the number of tunica layers fluctuated from 1 to 3, and there were occasional periclinal divisions in L‐II. This lack of discreteness of the second layer probably accounts for the homogeneity of all tissue beneath the superficial layer. The rarity of periclinal divisions in L‐I explains the stability of 2–4 types, but reversions are not impossible. The relative frequency of the different types of sports is discussed in relation to their possible origin. The theory of intraclonal variability developed in grapes by Reichardt (1955) and Rives (1961) on the basis of a multilayered shoot apex is re‐evaluated under the concept of a functionally uniseriate tunica.
A CHROMATOGRAPHIC STUDY OF RETICULATE EVOLUTION IN THE APPALACHIAN ASPLENIUM COMPLEX
Authors: Smith Dale M. , Levin Donald A.
Published: January 2018

Smith, Dale M. and Donald A. Levin. (U. Illinois, Urbana.) A chromatographic study of reticulate evolution in the Appalachian Asplenium complex. Amer. Jour. Bot. 50(9): 952–958. Ilus. 1963.—The reticulate relationships of the members of the Appalachian Asplenium complex were studied by means of paper chromatography. Substances could be observed with ultraviolet light in the presence of ammonia vapor in all the taxa of the complex. The diploid species (A. montanum, A. platyneuron and A. rhizophyllum) had characteristic biochemical substances. Interspecific hybrids and/or their allotetraploid derivatives showed a complete complementation of all the substances of their known or presumed diploid ancestors. A combination of all the substances of the 3 diploids was found in the hybrids A. X kentuckiense and A. X gravesii. The results agree in all respects with the concept of reticulate evolution in the group which was advanced by Wagner on the basis of comparative morphology, hybridization and karyology.
THE ANATOMIC RESPONSES OF DAUCUS CAROTA TO THE ASTER YELLOWS VIRUS
Authors: Struckmeyer B. Esther
Published: January 2018

Struckmeyer, B. Esther. (U. Wisconsin, Madison.) The anatomic responses of Daucus carota to the aster yellows virus. Amer. Jour. Bot. 50(9): 959–963. Ilus. 1963.—The leaves, petioles, and roots of carrots (Daucus carota) displaying aster yellows virus in the field and those infected with the aster yellows virus inoculated by the 6‐spotted leafhopper were examined anatomically. Compared to the uninoculated, the young infected leaves displayed fewer layers of palisade cells and larger spongy parenchyma cells with a more compact arrangement. Mature leaves of infected plants sometimes were undulated and had few chloroplasts, many of which appeared fragmented. Hypertrophy and hyperplasia in the phloem tissue were associated with some necrosis and obliteration of cells. Long, needle‐shaped crystalline inclusion bodies were present in the phloem in the leaves and roots. Most of the vascular bundles of the petiole were abnormal. Malformations included proliferating phloem cells, which in some instances almost encircled the bundle, hyperplasia of the phloem, hypertrophy of the parenchyma, and considerable necrosis and obliteration of these cells. Other responses included the division into 3 or 4 rows of the large outer phloem parenchyma by parallel walls so that a cambium‐like layer was simulated. The tissue enclosed by this layer divided and underwent considerable necrosis and gummosis. Lacunae were found between the phloem bundle cap and the older phloem. Some of the cells in the phloem tissue differentiated into bundles with xylem. Numerous, short, lateral roots were conspicuous on the main root. The most noticeable response of the root tissue to this malady was hyperplasia and hypertrophy of the phloem followed by cellular disorganization, necrosis, and obliteration of cells. Some sieve tubes, companion cells, and parenchyma contained a gumlike deposit.
THE SPECIES OF ZIZIPHUS INDIGENOUS TO UNITED STATES AND MEXICO
Authors: Johnston Marshall C.
Published: January 2018

Johnston, Marshall C. (U. Texas, Austin.) The species o Ziziphus indigenous to United States and Mexico. Amer. Jour. Bot. 50(10): 1020–1027. Illus. 1963.—Taxonomic treatment is presented for the 7 species of Ziziphus P. Mill. (Rhamnaceae: Dicotyledoneae) recognized in United States and Mexico, with key, synonymies, descriptions, and distribution maps. The taxon Condaliopsis is restored to Ziziphus after having been treated as a subgenus of Condalia Cav. for more than 60 years on the basis of superficial vegetative characters. The name Z. sonorensis S. Wats. for the widespread Mexican species is replaced by the prior Z. amole (Sessé & Moçiño) comb. nov. The genus Sarcomphalus P. Br. is referred to Ziziphus, the type species becoming Z. sarcomphalus (L.) comb. nov. Some fossil remains attributed to this genus are mentioned, but phyletic speculations arc advisedly postponed until the whole genus and related genera can be reviewed.
EVIDENCE OF RELATIONSHIP BETWEEN EXTRA DIMINUTIVE CHROMOSOMES IN GEOGRAPHICALLY REMOTE RACES OF OENOTHERA
Authors: Cleland Ralph E. , Hyde Beal B.
Published: January 2018

Cleland, R. E. (Indiana U., Bloomington), and B. B. Hyde. Evidence of relationship between extra diminutive chromosomes in geographically remote races of Oenothera. Amer. Jour. Bot. 50(2): 179–185. Illus. 1963.—Two California races of O. hookeri, Mono (from Mono Co.) and Mataguey (from San Diego Co.), have extra diminutive chromosomes. These diminutives do not associate with any of the normal chromosomes present. The extras from the 2 races, however, are able to synapse with each other and to form chiasmata, although the extras in Mono are distinctly larger than these in Mataguey. This suggests that they are at least partially homologous and that they have come from a common source. Two alternative hypotheses for their origin are suggested: (1) they have resulted from the loss of pairing ends through deletion, having descended from the same chromosome; (2) they represent normal chromosomes derived from another subgenus, through an inter‐subgeneric cross followed by a backcross to hookeri. The facts tend to favor the latter hypothesis.
OBSERVATIONS ON THE FINE STRUCTURE OF OEDOGONIUM. II. THE SPERMATOZOID OF O. CARDIACUM
Authors: Hoffman Larry R. , Manton Irene
Published: January 2018

Hoffman, L. R., and Irene Manton. (U. Leeds, England.) Observations on the fine structure of Oedogonium. II. The spermatozoid of O. cardiacum. Amer. Jour. Bot. 50(5): 455–463. Illus. 1963.—Salient features of the fine structure of the spermatozoid of Oedogonium cardiacum are described and illustrated as they appear in whole mounts and in sections. There is a close resemblance to the zoospore of the same species (Hoffman and Manton, 1962) though the gamete is smaller and in some respects simpler. The flagella, though similar in length to those on the zoospore, are fewer (ca. 30 instead of ca. 120 per cell). The construction of the flagellar ring is similar though there is less mechanical material associated with the flagellar bases in the gamete. Compound “roots” alternating with the flagellar bases are identical in structure and relative position in both types of motile cells; there is no direct connection with the nucleus. Other details of resemblance and difference between the spermatozoid and the zoospore are discussed.
ULTRASTRUCTURE OF DIFFERENTIATED CELLS IN HIGHER PLANTS
Authors: Esau Katherine
Published: January 2018

Esau, Katherine. (U. California, Santa Barbara.) Ultrastructure of differentiated cells in higher plants. Amer. Jour. Bot. 50(5): 495–506. Illus. 1903.—This paper reviews the rather meager information on differences between meristematic and fully differentiated cells of higher plants at the ultrastructural level. It includes personal observations on differentiated cells in Cucurbita maxima and Vitis vinifera, particularly those of the phloem tissue. The structures considered and illustrated by means of electron micrographs are vacuoles, the nucleus, mitochondria, the endoplasmic reticulum, dictyosomes, plasmodesmata, and, briefly, plastids.
TRACHEARY ELEMENTS OF THE FERNS II. MORPHOLOGY OF TRACHEARY ELEMENTS; CONCLUSIONS
Authors: White Richard A.
Published: January 2018

White, R.A. (U. Michigan, Ann Arbor.) Tracheary elements of the ferns, II, Morphology of tracheary elements; conclusions. Amer. Jour. Bot. 50(6): 514–522. Illus. 1963.—With an increase in evolutionary divergence there is an increase in the frequency of occurrence within each family of alternate and opposite pits. Although typical fern tracheids are long, slender, tapered and scalariformly pitted, those located in the roots of ferns become modified with regard to lateral pitting, presence of end plates and the occurrence of perforations. Although end plates most frequently occur in root tracheids, they occur also in the petiole and infrequently in the rhizome tracheids. The large scalariform pits on shortened, oblique end plates contrast sharply with the small alternate and opposite pits of the lateral walls. Such tracheary cells often have the aspect of true vessel members. Marsilea possesses perforate end plates, thus true vessel members, in the root. Woodsia ilvensis and Notholaena sinuala both have root tracheary elements which appear to be vessel members, but because true perforations in the end plates have not been experimentally demonstrated, they are referred to as “presumptive vessel members.” The following morphological changes, (1) shortening of the tracheary elements; (2) increase in the occurrence of modified (alternate and opposite) pits on the lateral walls; (3) increase in the occurrence of end plates; and (4) a sporadic occurrence of true (Pteridium aquilinum, Marsilea quadrifolia) or presumptive vessel members (Woodsia ilvensis and Notholaena sinnata), all appear to be related to an increase in evolutionary divergence.
SOME CULTURAL AND GENETIC ASPECTS OF A NEW HETEROTHALLIC SORDARIA
Authors: Fields William G. , Maniotis James
Published: January 2018

Fields, William G., and James Maniotis. (Wayne State U., Detroit, Mich.) Some cultural and genetic aspects of a new heterothallic Sordaria. Amer. Jour. Bot. 50(1): 80–85. lllus. 1963.— Sordaria heterothallis sp. nov., isolated from rabbit dung collected in Austin, Texas, is characterized as a spermatium‐prcducing, hcterothallic Sordaria with carbonous stromatic walls. Spermatia may germinate, but their low frequency of germination suggests their role in asexual reproduction is minor. The fungus was determined to be biotin‐ and thiamine‐deficient. A single pair of factors about 1.9 units from the centromere governs compatibility. Ordered tetrad analyses indicates regular segregation of factors for ascospore germination, the production of aerial mycelium and pigmentation. Intra‐ and intergeneric reactions stimulating protoperithecial production occurs between Sordaria heterothallis and the related species Sordaria brevicollis and Gelasinospora atilosleira.
EFFECT OF INITIAL SIZE ON GROWTH OF PLANT TISSUE CULTURES
Authors: Caplin Samuel M.
Published: January 2018

Caplin, Samuel M. (LOS Angeles State Coll., Los Angeles, Calif.) Effect of initial size on growth of plant tissue cultures. Amer. Jour. Bot. 50(1): 91–94. Illus. 1963.—Using different slice thicknesses and cannula diameters, cylindrical expiants of different size were obtained from tubers of Jerusalem artichoke. Slice thickness ranged from 0.5 to 2.5 mm and expiant diameter from 1.30 to 3.22 mm. Initial fresh weights ranged from 2.3 to 29.8 mg, a 13‐fold range. After 17 days growth at 26 C in 10 ml basal medium containing 15% coconut milk, relative increase was inversely related to initial weight and ranged from 36‐fold for 2.3‐mg expiants to 8‐fold for 29.8‐mg expiants, a range of 4.5 × in relative increase between the largest and smallest cultures. Secondary phloem expiants of the same diameter from carrot root slices of different thickness, all removed at 1 mm from the cambium, also showed decreased relative growth with increasing size of explant; this was true for each of the different diameters used. Further investigation showed clearly that the growth of the large inocula was not limited by the amount of culture medium used during the period of culture. Initial weight has, therefore, a decided effect on the rate of relative growth.
GROWTH FACTOR INTERACTIONS IN THE TISSUE CULTURE OF TUMOROUS AND NONTUMOROUS NICOTIANA GLAUCA‐LANGSDORFFII
Authors: Schaeffer Gideon W. , Smith Harold H. , Perkus Marion P.
Published: January 2018

Schaeffer, Gideon W., Harold H. Smith and Marion P. Perkus. (Brookhaven Natl. Lab., Upton, N. Y.) Growth factor interactions in the tissue culture of tumorous and nontumorous Nicotiana glauca‐langsdorffii. Amer. Jour. Bot. 50(8): 766–771. Illus. 1963.—Tissues representing tumorous and nontumorous Nicotiana glauca‐langsdorffii were cultured on high (5 ×) and low (1 ×) concentrations of a modified White's basal medium containing 2.9 × 10–6m indoleacetic acid. The growth responses of tissues of both the tumorous and nontumorous genotypes to supplements of kinetin, glutamine, inositol and nucleic acid constituents added singly and in all combinations were noted on high‐salt media. The nucleic acid components inhibited growth and were omitted from low‐salt media. The best growth response was observed with glutamine and inositol for tissues from the tumorous hybrid and with glutamine, inositol and kinetin in the nontumorous type. Kinetin was a distinct and consistent requirement for rapid growth of nontumorous tissues, but no appreciable kinetin effect could be observed with tissues from the tumorous genotype.
DEVELOPMENT AND PHYLLOTAXIS OF THE VEGETATIVE AXILLARY BUD OF MICHELIA FUSCATA
Authors: Tucker Shirley C
Published: January 2018

Tucker, Shirley C. (Northwestern U., Evanston, III.) Development and phyllotaxis of the vegetative axillary bud of Michelia fuscata. Amer. Jour. Bot. 50(7): 661–668. Illus. 1963.—The vegetative axillary buds of Michelia fuscala are dorsiventrally symmetrical with 2 ranks of alternately produced leaves. The direction of the ontogenetic spiral in each of these buds is related both to the symmetry of the supporting branch and to the position of the bud along the branch. On a radially symmetrical branch, all the axillary buds are alike—all clockwise, for example. But in a dorsiventrally organized branch the symmetry alternates from clockwise in 1 axillary bud to counterclockwise in the next bud along the axis. Leaf initiation and ontogeny of the axillary apical meristem conform with those of the terminal vegetative bud. The axillary bud arises as a shell zone in the second leaf axil from the terminal meristem. During this process the axillary apex develops a zonate appearance. The acropetally developing procambial supply of the axillary bud consists wholly of leaf traces. At the nodal level the bud traces diverge from the same gap as the median bundle trace of the subtending leaf. Only the basal 1–2 axillary buds which form immediately after the flowers elongate each year, while the majority remains dormant with 3 leaves or fewer.
A RELATIONSHIP BETWEEN CELL WALL STRUCTURE AND COLONIAL GROWTH IN NEUROSPORA CRASSA
Authors: de Terra Noël , Tatum E. L.
Published: January 2018

de Terra, Noël, and E. L. Tatum. (Rockefeller Inst., New York, N. Y.) A relationship between cell wall structure and colonial growth in Neurospora crassa. Amer.Jour. Bot. 50(7): 669–677. Illus. 1963.—Cell walls were isolated from morphological mutants of Neurospora crassa and from their corresponding wild‐type strains. Acid hydrolysates prepared from these cell walls were then studied, qualitatively and quantitatively, with respect to their reducing sugar content. Paper chromatography revealed the presence of glucose and glucosamine in the cell walls of all strains studied. Quantitative analysis has shown that a group of 4 colonial mutants which strongly resemble each other in morphology all have significantly less glucose and more glucosamine per unit weight of cell wall than do their corresponding wild‐type strains. These data strongly suggest that a particular type of morphological aberration in Neurospora is associated with similar changes in cell wall composition.
THE AFFINITIES OF PRINSEPIA (ROSACEAE)
Authors: Sterling Clarence
Published: January 2018

Sterling, C. (U. California, Davis.) The affinities of Prinsepia (Rosaceae). Amer. Jour. Bot. 50(7): 693–699. Illus. 1963.—Anatomical study of the carpels of 4 species of Prinsepia has shown that at flowering the 2 ovules are erect and pleurotropic. The funiculus is on the dorsal and lower side of the ovule; the micropyle faces a large obturator on the ventral side. The carpellary margins are separated by a fissure below the funicular insertion, but above this level they are fused. The style is laterally inserted on the ventral face of the carpel; it is vascularized only by the wing bundles and the recurving dorsal bundle. At the base of the ovary, 2 ovular bundles depart from the vascular cylinder and run separately, each to its respective ovule. In carpel morphology, ovular position, ovule structure, and vascular anatomy, Prinsepia is not a prunoid type. Although its features on the whole resemble those of chrysobalanoid plants, there are notable differences. Consequently, Prinsepia is assigned to a new subfamilial group in the Rosaceae, the Prinsepioideae. Some phylogenetic considerations are discussed briefly.
NATURAL HYBRIDIZATION BETWEEN PHLOX MACULATA AND PHLOX GLABERRIMA AND ITS EVOLUTIONARY SIGNIFICANCE
Authors: Levin Donald A.
Published: January 2018

Levin, 1). A. (U. Illinois, Urbana.) Natural hybridization between Phlox maculata and Phlox glaberrima and its evolutionary significance. Amer. Jour. Bot. 50(7): 714–720. Illus. 1963.—Field and herbarium studies indicate that Phlox maculata ssp. pyramidalis is similar to P. glaberrima ssp. interior in a number of characteristics. A hybrid swarm involving P. maculata ssp. maculata and P. glaberrima ssp. interior was discovered which contained some plants that were almost identical to P. maculata ssp. pyramidalis. Crosses between P. maculata and P. glaberrima indicate that the 2 species cross readily. The chromosome complements of the 2 species are morphologically similar. These data suggest that P. maculata ssp. pyramidalis is a stabilized introgressant type.
STUDIES ON THE ECOLOGICAL AND PHYSIOLOGICAL SIGNIFICANCE OF AMPHICARPY IN GYMNARRHENA MICRANTHA (COMPOSITAE)
Authors: Kollwr Dov , Roth Nurit
Published: January 2018

The 2 types of fruit (aerial and subterranean) borne by the dwarf desert annual Gymnarrhena micrantha were compared with regard to their responses to factors affecting their formation, dispersal, germination and seedling mortality. The 2 types of fruit differed markedly in several respects. In comparison with the subterranean fruits, the aerial ones are much smaller and more numerous, but the formation of the inflorescence in which they develop is more dependent on a favorable supply of soil moisture. The aerial fruits are dispersed by wind, after becoming detached by a complex series of hygroscopic movements which involve several organs and tissues, while the subterranean fruits never leave the dead parent plant, germinating right through its tissues. Germination of the subterranean fruits starts after a shorter incubation period and is less temperature‐dependent in both light and dark. Light stimulated germination of both types of fruit, increasing their germination rates and final percentages, but not affecting the duration of the incubation period. In the subterranean fruits, the rate of germination was equally stimulated by light over the entire temperature range, with a well‐defined optimum at 15 C in both light and dark. In the aerial fruits, the same optimum was found only in the light, rates in darkness increasing with decreasing temperatures. In the aerial fruits, alternations of light and dark were more favorable to germination than either continuous light or dark, the full effect being obtained with a single 8‐hr or 16‐hr light period, provided it was preceded by 16 or 8 hr of darkness, respectively. Similar reactions to combinations of light and dark were not observed in the subterranean fruits. Seedlings developing from the subterranean fruits were much larger, but grew at a relatively much slower rate than those from aerial fruits. The former were distinctly more tolerant of unfavorable soil‐moisture regimes, such as low moisture supply and drought. It was concluded that the 2 types of fruit serve 2 distinct functions in the biology of the plant. The aerial fruits are adapted to the function of increasing the distribution of the species within suitable habitats, while the subterranean fruits are adapted to increasing the probability of the survival of the species.
FINE STRUCTURE AND CYTOCHEMISTRY OF LILIUM POLLEN TUBES
Authors: Rosen W. G. , Gawlik S. R. , Dashek W. V. , Siegesmund K. A.
Published: January 2018

Growth of the Lilium longiflorum pollen tube in vitro is restricted to a zone extending back 3–5 μ from the tip. Electron micrographs of cross and longitudinal thin sections of L. longiflorum and L. regale pollen tubes reveal that the cytoplasm of the nongrowing region of the tube contains an abundance of mitochondria, amyloplasts, Golgi bodies, endoplasmic reticulum, lipid bodies, and vesicles. In contrast, the growing tip is characterized by an abundance of vesicles and an absence of other cytoplasmic elements. The vesicles appear to be of 2 types. One is spherical, about 0.1 μ in diameter, stains strongly with phosphotungstic acid, apparently arises from the Golgi apparatus and appears to contribute to tube wall and plasmalemma formation. The other type is irregular in shape, 0.01‐0.05 μ in diameter, stains strongly with lead hydroxide, and is of unknown origin and function. Cytochemical analysis indicates that the tips of L. longiflorum pollen tubes are singularly rich in ribonucleic acid, protein, and carbohydrate. These findings are discussed in relation to tube growth.
AN EXPERIMENTAL STUDY OF THE FLORAL ECOLOGY OF DODECATHEON MEADIA
Authors: Macior Lazarus Walter
Published: January 2018

An established colony of Dodecatheon meadia on glacial drift in southeastern Wisconsin was observed for its insect pollination interrelationships. Twelve randomly distributed plants from which insects were excluded failed to produce seed, while plants exposed to insect visits set abundant seed. Female solitary bees of 2 species, viz., Augochloropsis metallica fulgida (Smith) and Lasioglossum forbesii (Robertson), and queens and workers of 7 species of Bombus were observed collecting pollen from the pendant anther cone by rapid wing vibration, while hanging inverted from the cone tip. This behavior—cinematographically recorded—was found fundamentally identical to that of females of the same species of solitary bees and of queens and workers of 5 species of Bombus on Solanum dulcamara, and of females of Lasioglossum forbesii (Robertson) and workers of 2 species of Bombus on Lycopersicum esculentum Mill. No other insects were found to pollinate these morphologically similar flowers in this manner, and crepuscular pollinators were not observed. Experimental modifications of form, function, and position of Dodecatheon flowers were offered to the pollinators, and behavioral changes of the insects were noted. Constituents of insect pollen loads were examined, and relationships of the pollinators to the flora of the region were noted. The detailed ecological study of insect pollen vector behavior as an aid in discovering biosystematic relationships of plant populations is suggested.
NUCLEAR MIGRATION IN DIKARYOTIC‐HOMOKARYOTIC MATINGS IN SCHIZOPHYLLUM COMMUNE
Authors: Ellingboe Albert H.
Published: January 2018

The present data indicate internuclear selection in dikaryotic‐homokaryotic matings is not due to differential rates of migration of the 2 types of migrant nuclei or to differential rates of saturation of the homokaryon. The advancing fronts of the 2 types of migrating nuclei are separated by essentially the same distance shortly after migration has been initiated and during later periods in the migration process. Internuclear selection, controlled by the incompatibility factors, must occur during the initiation of migration or earlier. Migration of both types of nuclei from the dikaryon has been demonstrated in hemicompatible and incompatible matings.
CULTURE AND DEVELOPMENTAL MORPHOLOGY OF COMPSOPOGON COERULEUS
Authors: Nichols H. Wayne
Published: January 2018

Compsopogon coeruleus has been grown in culture for 4 years. The life‐history consists of reproduction by monospores and their germination and growth into erect filamentous (corticated or uncorticated) thalli. Plastids are parietal sheets in young cells but undergo characteristic divisions to form discoid segments in older cells. The chromosome number has been determined as 7 ± 1. Sporangia have been studied and their derivation compared to the sporangial types of Drew‐Baker. Variations in cell walls, basal systems, spore germination and young plantlets are discussed.
INORGANIC NITROGEN NUTRITION OF THE SEEDLINGS OF THE ORCHID, CATTLEYA
Authors: Raghavan V. , Torrey John G.
Published: January 2018

When grown in vitro in a medium containing NH4NO3 as the sole source of nitrogen, seeds ro the orchid, Cattleya (C. labiata ‘Wonder’ X C. labiata ‘Treasure'), germinated readily and proceeded to form small plantlets. Development of the embryos was accompanied by an increase in their total nitrogen and a decline in the percent dry weight. Growth responses of the seedlings in other ammonium salts like (NH4)2SO4, (NH4)2HPO4, NH4Cl, ammonium acetate and ammonium oxalate were similar to that in NH4NO3. However, when grown in a medium containing NaNO3, development of the seedlings was drastically inhibited; KNO3, Ca(NO3)2, KNO2 and NaNO2 also were poor nitrogen sources. Attempts to grow the seedlings in NaNO3 by changing the pH or by addition of kinetin, molybdenum or ascorbic acid as supplements were completely unsuccessful. When seedlings growing in NH4NO3 for varying periods were transferred to NaNO3, it was found that those plants allowed to grow for 60 or more days in NH4NO3 could resume normal growth thereafter in NaNO3. Determination of the nitrate reductase activity in seedlings of different ages grown in NaNO3, after NH4NO3, showed that the ability of the seedlings to assimilate inorganic nitrogen was paralleled by the appearance of the enzyme.
GENETIC CONTROL OF CONIDIATION IN ASPERGILLUS RUGULOSUS
Authors: Coy D. O. , Tuveson R. W.
Published: January 2018

The potential for the production of abundant conidia was suggested when an essentially non‐conidial isolate of Aspergillus rugulosus, obtained from dune sand, was grown at 25 C rather than at the usual 37 C. Ultraviolet‐light‐induced conidial strains were obtained from the original non‐conidial isolate. Evidence is presented which suggests that the production of conidia is under the control of a single nuclear gene. The data, with a single exception, suggest that induced conidial mutations represent alterations at the same locus. Crosses with isolates from various localities indicate that the genes controlling conidiation in these strains may be linked to or independent of the genes studied in the original dune‐sand isolate. No evidence has been obtained which would suggest involvement of a diffusible substance in the control of conidiation.
BENZYLADENINE EFFFCTS ON BEAN LEAF GROWTH AND SENESCENCE
Authors: Leopold A. C. , Kawase M.
Published: January 2018

Experiments concerning the effects of benzyladenine applications on the growth and senescence of leaves have been carried out with cuttings of bean seedlings. By measuring the interactions between leaves, it was found that this kinin not only can stimulate the growth of a treated whole leaf, but it can bring about the inhibition of growth in other untreated leaves on the same plant. Consistent, with the apparent mobilizing actions of this chemical, it was found that applications to one or more leaves would induce the senescence of untreated leaves in a manner similar to the senescence‐inducing effects of stem apices and flowers and fruits. The experiments suggest that the mobilization effects due to natural kinins in such centers in the intact plant may provide endogenous stimuli of leaf senescence.
SEGREGATION IN NEW ALLOPOLYPLOIDS OF GOSSYPIUM. V. MULTIVALENT FORMATION IN NEW WORLD X ASIATIC AND NEW WORLD X WILD AMERICAN HEXAPLOIDS
Authors: Phillips Lyle L.
Published: January 2018

The New World tetraploid cottons, G. hirsutum and G. barbadense, are natural amphidiploids (genome formula, 2[AD]) combining species of the cultivated Asiatic (2A) and wild American (2D) groups of diploid cottons. Multivalent frequency, per cell, for 2 New World X Asiatic synthetic hexaploids, G. hirsutum X G. arboreum and G. barbadense X G. arboreum, is 6.68 and 7.80, respectively. Multivalents per cell for a series of New World X wild American synthetic hexaploids are: New World X G. harknessii, 3.65;— X G. armourianum, 3.96;— X G. aridum, 3.48;— X G. lobatum, 3.66; — X G. gossypioides, 1.13. The expected correlation between multivalent frequency and genetic segregation (e.g., high multivalent frequency = high recovery of recessives, and vice versa) for these hexaploids is realized for the near‐allopolyploids (New World X wild American) but only approximated for the near‐autopolyploid combinations, New World X Asiatic. This is explained on the basis that different homogenetic:heterogenetic bivalent ratios are expected in autopolyploids as compared to allopolyploids.