中国下泥盆统脊椎动物化石组合层序

本文综合了滇、黔、川、桂等地的一些早泥盆世地层剖面中的脊椎动物化石的出露情况,粗略地描绘出了早期脊椎动物演化的一般特征,归纳成三个发展阶段。并以此为依据,讨论了下泥盆统的分层与对比。     

Gingival eruption sequences of permanent teeth in early hominids.

Gingival eruption of the permanent teeth of Australopithecus, Paranthropus, and early Homo, diagnosed from enamel scratches and facets, is similar save for two sequences: eruption of the canines relative to the premolars which may be sexually dimorphic; and agenesis of M3 with delayed eruption of M2, first seen in Homo at two million years. Gingival eruption sequences are similar also for early and modern Homo, except that in some individuals today M3, M2, M1 and I2 take longer to form and emerge through the gingiva as functioning teeth. Probably, from two million years to the present in the evolutionary history of Homo dental development slowed-down. More and more of ontogeny has been taken over for eruption.     

Recent freshwater oscillatoriacean analogue of the Lower Palaeozoic calcareous alga Angulocellularia

Recent freshwater cyanophyte oncoids from Canandaigua Lake, New York, consist almost entirely of minute irregular, bush-like, micritic masses comparable with the calcareous alga Angulocellularia Vologdin from Lower Cambrian algal-arehaeocyathan bioherms and biostromes of the Siberian Platform and western Mongolia. The Recent specimens arc radially orientated within the oncoids and occasionally contain moulds of axial filaments 15 μm in diameter. Acid-residues of the oncoids yield abundant Schizothrix calcicola. The micritic bush-like masses are interpreted to have formed by the calcification of the sheaths of these cyanophytes. This analogue allows Angulocellularia to be reinterpreted as a calcified oscillatoriacean cyanophyte, rather than a rhodophyte as previously suggested. It indicates that filamentous cyanophytes can produce apparently solid calcareous fossils, not only porostromatc tubes. The occurrence of Angulocellularia has been overlooked in some previous studies of Cambrian and Ordovician bioherms. The generic diagnosis is emended.     

A vigorous mutant sugarcane (Saccharum sp.) clone Co 527

Summary A vigorous fast growing mutant which ends vegetative growth sixty days earlier than the parent variety Co 527 was isolated from gamma irradiated vegetative buds. The mutant initially segregated but stabilized in the vM₄ generation. Its growth rate was almost fifty per cent higher than Co 527 beginning in the early stages of growth. It produced a significantly higher early shoot population which enabled it to yield a higher number of millable canes at maturity. Economic characters like sucrose content and juice purity remained unaffected. This mutant had a chromosomal basis in that the number was 2 to 3 lower than in the parent variety.Research carried out under the FAO/IAEA Co-ordinated Research Programme on the Improvement of Vegetatively Propagated Plants and Tree Crops through Induced mutations (Research Contract No. 1680)     

湘西北志留纪胴甲鱼化石

本文记述了采自湘西北澧县石门水库附近秀山组上段隶属云南鱼目的 Shimenolepis graniferus gen. et sp. nov. 和 QuJinolepidae gen. et sp. indet. 化石,对含鱼层的时代也进行了讨论.     

宁夏、内蒙古的一些早白垩世珠蚌类

宁夏六盘山群上部和内蒙古赛汉塔拉组产出的珠蚌类化石为首次描述,其面貌与邻区相当地层产出的蚌类相似,前人将它们鉴定为Unio。现据它们的壳顶区缺双带构造、前假主齿乳头状并不呈“多”形排列和前闭壳肌痕内具树枝状构造等特征建立Ningxiaconcha gen. nov.。本文还对Pseudelliptio属及其模式种的含义作了补充修订;通过这些珠蚌类化石的对比,宁夏六盘山群和内蒙古赛汉塔拉组可与新疆吐谷鲁群中上部、辽西沙海组和阜新组、山东蒙阴群中上部、浙江寿昌组上段以及苏联、蒙古、德国韦尔登阶进行对比,其时代应归入早白垩世早期。     

广西隆林祥播中二叠世生物礁的钙藻化石

本文描述了广西隆林祥播中二叠世茅口期生物礁中的钙藻化石17属18种,其中新属5个:Paralithoporella gen. nov., Guangxilamina gen. nov., Favoporella gen. nov., Sinophyllum gen. nov.,和Monostysisyrinx gen. nov.; 新种9个:Solenopora guangxien sis sp. nov., Paralithoporella sincrisis gen. et sp. nov., Guangxilamina incompta gen. et sp. nov., Favoporella hexagona gen. et sp. nov., Ivanovia permica sp. nov., Anchicodium expressum sp. nov., Sinophyllum hexagonum gen. et sp. nov., Sphaeroporella minima gen. et sp. nov., Monostysisyrinx circula ris gen. et sp. nov.。本文还建立一新科——Monostysi sy rinaceae。在当前生物礁中,钙藻是重要的造礁生物,可以起造架、粘结、障积等作用,也可作为居礁生物或造粒生物     

RNA synthesis during early embryogenesis of mass cultured highly synchronized coleopteran embryos

Summary Bruchidius embryos are shown to be well suited for biochemical studies during early embryogenesis. Mass cultivation is easy, and highly synchronized embryos can be obtained in large numbers (10⁴–10⁵ eggs). A method for in vivo incubation is described which allows the labelling of newly synthesized RNA. The kinetics of³H-ruidine uptake, phosphorylation and incorporation into RNA are presented. By autoradiography, the distribution of newly synthesized RNA is shown. Thereby, stage-specific differences were found in the labelling pattern of vitellophage nuclei, of blastoderm nuclei and of the nuclei of pole cells. The labelling of the cytoplasm remains weak until cellular blastoderm is formed. During late blastoderm and at gastrulation this label increases markedly. Gel electrophoresis of isolated RNA shows that at cellular blastoderm formation most of the label occurs in a region between 18 S and 7 S. Later on, at the onset of gastrulation, the³H-uridine incorporation found in isolated RNA is raised about 10 fold and rRNA synthesis becomes prominent. In a chase experiment, the processing of precursor RNA molecules into shorter RNA species, especially into mature rRNA and 5S RNA, is shown. The advantages of theBruchidius embryo for the biochemical analysis of early RNA synthesis and the regulation of rRNA synthesis in insect embryos are discussed.Dedicated to Professor Dr. Dr. h. c. Bernhard Rensch at the occasion of his 80th birthday