首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
《Plains anthropologist》2013,58(60):149-159
Abstract

While gathering economic and environmental data from the Mitchell site in 1971, one house and part of anotherwere excavated. The more completely excavated structure had burned, and provided evidence for a number of architectural features. This house was a rectangular structure with walls of wattle and daub construction and a roof composed of poles overlain by willows and grass. Both houses were constructed in pits, cut into a deeply buried, black “fossil” soil which appears to represent the prairie soil at the time the site was initially occupied. The surface of this fossil soil was buriedabout three feet below the modern surface by a mantle of mixed soil and midden debris. Profiles from the burned house indicate that the thick mantle of mixed soil and midden was the result of banking the walls of the house with quantities of soil and habitation debris.  相似文献   

2.
3.
Plains Facts     
《Plains anthropologist》2013,58(13):201-212
Abstract

During the summer of 1960, 8 burial or storage pits were uncovered at the Leary site 25RH1, Richardson County, Nebraska by a bulldozer of the county highway department. A rush archaeological salvage excavation was conducted, Remains of at least 3 individuals were recovered, Pottery resembles that excavated from the site in 1935 by the Nebraska State Historical Society and is classified as Oneota, A wine bottle of the type manufactured by the William McCully Company of Pittsburgh, Pennsylvania between 1832 and 1890 was recovered from an undisturbed part of a storage pit. It is thought to be intrusive through rodent action.  相似文献   

4.
《Plains anthropologist》2013,58(66):306-315
Abstract

During the summer of 1970, a storage pit filled with canip debris was excavated by depositional levels at site DgMg-15. The pit had been used repeatedly while slowly being filled with habitation debris. Six hearths were in the pit, several of which had been carefully covered with layers of sterile gravel. The earliest hearth yielded a carbon-14 date of A.D. 1610 ±130 (GSC-1546). Evidence from these excavations indicates that important information can be lost by treating storage pits as single, homogeneous units of activity.  相似文献   

5.
《Plains anthropologist》2013,58(43):1-31
Abstract

The Blue Blanket Island site (39WW9), a small, fortified, proto-historic Indian village on an island in the Missouri River, in Walworth County, South Dakota, was partially excavated by a River Basin Surveys crew in August 1961. One centrally located earthlodge, sections of the fortification, storage pits, and middens were excavated. Artifacts were scanty but architectural details were informative. The lodge was 18 sided with a short entry wayto the south (river side) and leaner posts of split cedar. The palisade was of split posts and the ditch was wide and shallow. The site appears to have been an Arikara village of short duration, probably occupied during the 1780’s and 1790’s. The abandoned remains of this village were noted by Lewis and Clark in 1804.  相似文献   

6.
《Plains anthropologist》2013,58(50):255-281
Abstract

Edwards II is located on the North Fork of the Red River in western Oklahoma. It is one of two sites excavated in 1968 by the University of Oklahoma Field School in Archaeology. The major excavation area consisted of 19 contiguous five foot squares. Two test pits were also dug to determine the limits of the site. Nine features were uncovered; all were pits which exhibited a variety of shapes. Ceramic materials and projectile points are similar to Custer and Washita River foci manifestations, but the low proportion of bison bone, and the presence of a few corner notched and stemmed points suggest placement early in the time span represented by these foci.  相似文献   

7.
《Plains anthropologist》2013,58(33):208-219
Abstract

A report of the contents of eleven cache pits found at the Fanning site.  相似文献   

8.
The basal part of cotton fibers (Gossypium arboreum and G. hirsutum) was studied with light and electron microscopy in order to improve the understanding of assimilate transport into the fibers during the deposition of the cellulosic secondary wall. Although the distal parts of white cotton fibers are not suberized, a variable amount of suberin was found at the fiber base. This suberin is typically deposited in concentric layers, alternating with polysaccharides. Numerous pits occur in the base of cotton fibers and in ordinary epidermal cells in the periclinal and anticlinal walls. About 25% of the length of periclinal walls is occupied by pits, but only 2% of the anticlinal walls, being pitted mainly in their proximal part. In suberized walls the deposition of suberin is not reduced in the pit region. The pits, whether or not suberized, contain plasmodesmata (22 ± 2.3 and 27 ± 3.3 · μm−-2 in the periclinal and anticlinal walls of the white lint cultivar of G. hirsutum). Transport of assimilates into the fibers through the symplast is therefore possible. This transport may occur directly from mesophyll cells to fibers, or indirectly via ordinary epidermal cells. The minimum amount of assimilates transported into individual fibers during the phase of secondary wall deposition could be estimated (1.3 pg · fiber−-1 · sec−-1), as well as the corresponding symplastic flux of assimilates through the periclinal cell wall, neglecting a possible transport through the anticlinal walls (10−-3 pg · μm−-2 · sec−-1). It is postulated that in the green lint genotype of G. hirsutum and in wild cotton species (not studied in this paper), the uptake of assimilates into the fibers occurs through the symplast, the apoplastic pathway being excluded by the suberization of the fibers during secondary wall formation. Although cultivated, white-linted cotton species may use the same pathway, loading of assimilates from the apoplast is theoretically also possible, and the relative contribution of both pathways has to be determined experimentally.  相似文献   

9.
《Plains anthropologist》2013,58(14):230-241
Abstract

Site 39BR201 is an earth-lodge village located in the upper Fort Randall reservoir, Brdle County, South Dakota. Excavation of 1/2 of each of 2 circular earth-lodges, a midden area, and 8 test pits was done in the late summer of 1954 by Paul L. Cooper of the Smithsonian Institution, River Basin Surveys. Talking Crow Straight Rim, Talking Crow Indented, and Cadotte Collared pottery types make up most of the rim sherd sample. The presence of a few fragments of brass and iron in the features indicates a date in the late 17th or early 18th centuries for the occupation of the site. The ceramic material is related to that from the Two Teeth site and the Talking Crow site.  相似文献   

10.
Arrays of cortical microtubules (MTs) on radial walls in differentiatingtracheids of Taxus cuspidata were randomly oriented when primarywalls formed. The orientation of MTs changed progressively fromlongitudinal to transverse as cells expanded. During formationof primary walls, MTs in differentiating tracheids disappearedlocally at sites of future intertracheal bordered pits. In furtherdifferentiated tracheids, circular bands of MTs were observedaround the edges of developing bordered pits. (Received July 17, 1996; Accepted November 11, 1996)  相似文献   

11.
《Journal of bryology》2013,35(2):187-193
Abstract

Analyses of populations of Grimmia doniana from Old Red Sandstone walls (Brecon Beacons, Breconshire) and vitrified lead slag (Charterhouse, Somerset) showed the former to have a low and the latter a high lead content. Lead in material from the field was shown to be ionically bound to an extracellular site. Uptake of lead from solutions of lead nitrate was by a passive physical process, without penetration of the cytoplasm. No difference in lead uptake capacity was detected between the two populations. The results are discussed in terms of a natural non-specific lead tolerance mechanism occurring in Grimmia doniana.  相似文献   

12.
The anatomy of the seed coat of the European species of tribe Ericeae (Calluna, Daboecia and Erica) of the Ericaceae family was studied, and the taxonomic importance of their characters was analyzed. The seed coat is mostly formed by a one-cell layer with thick, pitted inner walls and thin outer walls that collapse at maturity over the inner walls. The cell junctions are either raised with anticlinal walls up to four times the height of the periclinal walls or are not raised with similar values for the height of both the anticlinal and periclinal walls. Three main cell junction types were found and described. The thickness of the inner walls is variable, but there is a large overlap among the results for different species. Calluna vulgaris is the only species with no pits, and E. multiflora has a pitted pattern on its inner walls, which is distinctive from the rest of the species. Our main results agree with the external seed morphology, and valuable new data were obtained for certain groups such as the E. cinerea-E. terminalis or the E. scoparia complex. The similarities that are found in seed coat characters are not in accordance with the classical taxonomic delimitation of infrageneric groups within Erica.  相似文献   

13.
Atalodera ucri, Wouts and Sher, 1971, and A. lonicerae, (Wouts, 1973) Luc et al., 1978, induce similar multinucleate syncytia in roots of golden bush and honeysuckle, respectively. The syncytium is initiated in the cortex; as it expands, it includes several partially delimited syncytial units and distorts vascular tissue. Outer walls of the syncytium are relatively smooth and thickest near the feeding site of the nematode; inner walls are interrupted by perforations which enlarge as syncytial units increase in size. The cytoplasm of the syncytium is granular and includes numerous plastids, mitochondria, vacuoles, Golgi, and a complex network of membranes. Nuclei are greatly enlarged and amoeboid in shape. Although more than one nucleus sometimes occur in a given syncytial unit, no mitotic activity was observed. Syncytia induced by species of Atalodera chiefly differ from those of Heterodera sensu lato by the absence of cell wall ingrowths; wall ingrowths increase solute transport and characterize transfer cells. In syncytia of Atalodera spp., a high incidence of pits and pit fields in walls adjacent to vasctdar elements suggests that in this case plasmodesmata provide the pathway for increased entry of sohttes. The formation of a syncytium by species of Atalodera and Heterodera sensu lato, but a single uninucleate giant cell by Sarisodera and Hylonema, indicates a pattern of host responses that may be useful, with other characters, for phylogenetic inference for Heteroderidae.  相似文献   

14.
Sarcandra is the only genus of Chloranthaceae hitherto thought to be vesselless. Study of liquid-preserved material of S. glabra revealed that in root secondary xylem some tracheary elements are wider in diameter and have markedly scalariform end walls combined with circular pits on lateral walls. Examination of these wider tracheary elements with scanning electron microscope (SEM) demonstrated various degrees of pit membrane absence in the end walls. Commonly a few threadlike fibrils traverse the pits (perforations); these as well as intact nature of pit membranes in pits at ends of some perforation plates are evidence that lack of pit membranes does not result from damage during processing. Some perforations lack any remnants of pit membranes. Although perforation plates and therefore vessels are present in Sarcandra roots, no perforations were observed in tracheary elements of stems or lignotubers. Further, stem tracheids do not have the prominently scalariform end walls that the vessel elements in roots do. Presence of vessels in Sarcandra removes at least one (probably several) hypothetical events of vessel origin that must be postulated to account for known patterns of vessel distribution in angiosperms, assuming that they are primitively vesselless. Seven (perhaps fewer) vessel origin events in angiosperms could account for these patterns; two of those events (Nelumbo and monocotyledons) are different from the others in nature. Widely accepted data on trends of vessel specialization in woody dicotyledons yield an unappreciated implication: vessel specialization has happened in a highly polyphyletic manner in dicotyledons, and therefore multiple vessel origins represent a logical extension backward in time. If a group of vesselless dictyoledons ancestral to other angiosperms existed, they can be hypothesized to have had a relatively homogeneous floral plan now that Sarcandra-like plants no longer need be imagined within that group. Sarcandra and other Chloranthaceae show that the borderline between vessel absence and presence is less sharp than generally appreciated.  相似文献   

15.
Hong-Fang Li  Shu-Miaw Chaw 《Flora》2011,206(6):595-600
For almost 150 years, the two monotypic genera Trochodendron and Tetracentron (Trochodendraceae) have been considered to share an unusual and primitive feature in angiosperms - the lack of vessels in their wood. Therefore, they have been classified in a basal position in the angiosperms. Our observations by light microscopy, low-vacuum environmental scanning electron microscopy (ESEM) and high-vacuum scanning electron microscopy (SEM) both in fresh and FAA-fixed materials consistently showed the presence of tracheary elements differentiated into two types in both genera. In Trochodendron, the tracheary elements can be divided into perforate vessel elements and imperforate fiber-tracheids and tracheids. The vessel elements show end and lateral walls. The pits on the end walls are elongate- broadened and do not have membranes or only a few remnants of them forming the perforation plates. The fiber-tracheids show crossfield pit pairs and sharp ends, and the tracheids show bordered pits. In Tetracentron, the tracheary elements comprise vessel elements and fibers. The vessel elements are similar to those of Trochodendron, whereas the fibers have no crossfield pit pairs but, rather, elliptical pits and sharp ends. Thus, both Trochodendron and Tetracentron are vessel bearing rather than vesselless, although their vessel elements are primitive.  相似文献   

16.
Brian C. Monk 《Planta》1988,176(4):441-450
The cell walls of Chlamydomonas gametes are multilayered structures supported on frameworks of polypeptides extending from the plasma membrane. The wall-polypeptide catalogue reported by Monk et al. (1983, Planta 158, 517–533) and extended by U.W. Goodenough et al. (1986, J. Cell Biol. 103, 405–417) was re-evaluated by comparative analysis of mechanically isolated cell walls purified from several strains. The extracellular locus of wall polypeptides was verified by in vivo iodogen-catalysed iodination and by autolysin-mediated elimination of the bulk of these polypeptides from the cell surface. Three (w15, w16, w17) and possibly four (w14) polypeptides were located to the most exterior aspect of the wall because of their susceptibility to Enzymobeadcatalysed iodination and their retention by a cell-wall-less mutant. The composition of shed walls stabilised with ethylenediaminetetraacetic acid during natural mating and kinetic analysis of the dissolution of walls purified from a bald-2 mutant demonstrated the rapid and specific destruction of polypeptide w3. Differential solubilisation of wall polypeptides occurred after loss of w3. Wall dissolution, characterised by the generation of fishbone structures from the W2 layer, gave as many as four additional polypeptides. Charged detergents and sodium perchlorate extracted a comparable range of polypeptides at room temperature from mechanically isolated walls, i.e. components of the W4–W6 layers, hot sodium dodecyl sulphate solubilised framework polypeptides, while reducing agent was required to solubilise the W2 layer. A model of wall structure is presented.Abbreviations DTE dithioerythritol - EDTA ethylenediaminetetraacetic acid - Mr relative molecular mass - SDS-PAGE sodium dodecyl sulphate-polyacrylamide gel electrophoresis - Tris 2-amino-2-(hydroxymethyl)-1,3-propanediol  相似文献   

17.
The structure of tracheids in Lycopodium lucidulum, L. clavatum, and L. tristachyum was studied with the light microscope. Protoxylem development is at least sometimes and possibly always mesarch in indeterminate axes of all three species. Centrifugally formed protoxylem elements are reticulate and discontinuities in the secondary walls of these elements are sometimes conspicuously bordered. Wall thickenings of first formed protoxylem elements consist mainly of indirectly connected rings. Late centripetally formed protoxylem elements and transitional elements have a reticulate secondary wall pattern. The narrowest metaxylem elements have circular bordered pits while in wider metaxylem elements pits are bordered and may vary from circular to scalariform. Pitting is uniseriate to triseriate in tracheids of all three species, and intermittent tetraseriate pitting was occasionally observed in L. lucidulum. Crassulae occur in tracheids of the three species, and in L. clavatum an additional framework, probably representing thickened compound middle lamella, is also present. Pits often appear helically arranged, and in all three species pits are connected by thin areas in the secondary wall. Macrofibrils approximately 0.5 μ wide were observed in tracheids of the three species. In L. clavatum the arrangement of macro-fibrils was predominantly bidirectional.  相似文献   

18.
Summary The investigation of the formation of cell wall appendages inAcanthosphaera by means of light and electron microscopy and by the use of dyes which interfere with microfibril assembly resulted in several observations which are helpful to an understanding of the formation of normal cell walls. The barbs are built up in the ER, pass through the Golgi apparatus, and are extruded exocytotically after cytokinesis, a remarkable example of the secretion of a structured product. Each cellulose microfibril in a spike develops in a distinct pit of the plasmalemma. The pits are aggregated in a pit field, generating one spike, and are closely adjacent to a basal vesicle which might have morphogenetic and/or regulatory functions. The pits are the site of cellulose synthesis; here the plasmalemma is conspicuously thickened. As shown directly and by the application of Calcofluor white and Congo red, the microfibrils assemble at a certain distance from the plasma membrane,i.e. cellulose synthesis and microfibril assembly are separated by a gap. It is discussed whether single glucan chains or small bundles of them are released from the plasmalemma. The elongation rate of the spikes indicates that about 1000 glycosidic linkages per glucan chain per minute are formed.  相似文献   

19.
The formation of tracheary elements was induced in calli derived from petioles of hybrid poplar (Populus sieboldii × P. grandidentata) after 10 days of culture on medium that lacked auxin but contained 1 μM brassinolide. Some differentiated cells formed broad regions of cell walls and bordered pits, which are typical features of tracheary elements of secondary xylem. Other differentiated cells resembled tracheary elements of primary xylem, with spiral or reticulate thickening of cell walls. The tracheary elements that developed in calli were formed within cell clusters. This induction system provides a new model for studies of the mechanism of differentiation of secondary xylem cells in vitro.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号