云南大理洱海砂子箐组的时代及谢尔普霍夫阶地层的发现

云南大理洱海之东的砂子箐组产有牙形刺Scaliognathus anchoralis,Gnathodus typicus,Gnathodus cf.girtyi等化石,清楚地表明砂子箐组的地质时代为杜内期.在双廊镇大建旁村环海公路边灰岩中发现牙形刺Lochriea ziegleri,Gnathodus cantabricus,Gnathodus bilineatus remus,Gnathodus bilineatus romulus,充分证明海东地区谢尔普霍夫阶地层的存在.     

THE STRUCTURE OF THE ACERVULUS,THE FLOWER CLUSTER OF CHAMAEDOREOID PALMS

Developmental evidence shows that the acervulus, a distinctive flower cluster found only in the chamaedoreoid group of palms, is a form of cincinnus. In Hyophorbe indica Gaertner, the unit consists of a row of sessile flowers, the upper 3–4, staminate and the basal flower, pistillate. During initiation, each new flower originates from divisions in the T₂ and underlying layers of the lower right or left flank of the apex of the preceding flower. A bract subtending the first flower is evident in early stages, is displaced basipetally as the flowers are formed, but is obscured when flowers are mature. No other bracts are associated with the unit. One to two outer bundles of the vascular cylinder of the rachilla develop first to the uppermost flower. Subsequently, bundles to other flowers arise as lower branches of the first bundle and from other, often small outer bundles of the rachilla that become floral traces or produce one or more branches to a flower. Many of the bundles supplying the flowers bend sharply downward in the cortex of the rachilla, apparently reflecting the basipetal sequence of floral inception.     

THE STRUCTURE, ORIGIN, ISOLATION, AND COMPOSITION OF THE TUBULAR MASTIGONEMES OF THE OCHROMONAS FLAGELLUM

The structure, assembly, and composition of the extracellular hairs (mastigonemes) of Ochromonas are detailed in this report. These mastigonemes form two lateral unbalanced rows, each row on opposite sides of the long anterior flagellum. Each mastigoneme consists of lateral filaments of two distinct sizes attached to a tubular shaft. The shaft is further differentiated into a basal region at one end and a group of from one to three terminal filaments at the free end. Mastigoneme ontogeny as revealed especially in deflagellated and regenerating cells appears to begin by assembly of the basal region and shaft within the perinuclear continuum. However, addition of lateral filaments to the shaft and extrusion of the mastigonemes to the cell surface is mediated by the Golgi complex. The ultimate distribution of mastigonemes on the flagellar surface seems to be the result of extrusion of mastigonemes near the base of the flagellum, and it is suggested that mastigonemes are then pulled up the flagellum as the axoneme elongates. Efforts to characterize mastigonemes biochemically after isolation and purification on cesium chloride (CsCl) followed by electrophoresis on acrylamide gels have demonstrated what appear to be a single major polypeptide and several differentially migrating carbohydrates. The polypeptide is not homologous with microtuble protein. The functionally anomalous role of mastigonemes in reversing flagellar thrust is discussed in relation to their distribution relative to flagellar anatomy and to the plane of flagellar undulations.     

鲢疯狂病病原体鲢碘泡虫营养体的超微结构观察

本文报道鲢碘泡虫营养体的超微结构。叙述了两层结构的原生质膜,外质中的胞饮管道,各种长短的分枝管道、芽体和泡状体,双层核膜具有核孔,在胞饮管道的内层,有很多线粒体、高尔基器、内质网、溶酶体、核糖体、脂粒及各种大小和作用未明的颗粒、微丝等等,但未见中心粒。