三种石杉属植物孢子形态的扫描电镜观察

利用扫描电镜对采自湖北省利川市的蛇足石杉Huperzia serrata（Thunb.ex Murray）Trev.、皱边石杉H.crispate（Ching ex H.S.Kung）Ching和四川石杉H.sutchueniana（Herter）Ching3种植物孢子的大小、形态及表面纹饰等方面进行观察测量,并对每个种孢子形态特征进行了描述。结果表明,3种石杉属植物孢子均为四面体型、三裂缝、辐射对称,表面纹饰均呈穴状。不同种在孢子大小、裂缝长度、孔穴深浅程度以及辐射间区凹陷程度上存在差异。因孢子形态是稳定的,可作为种间划分的重要依据,同时,也为蕨类植物孢子形态学的研究提供参考。     

Indian chytrids. III. Species of rhizophlyctis isolated on human fibrin film

Summary Human fibrin film has been used as an additional substratum to trap zoosporic fungi in watered soil samples. This semi-transparent film is prepared from human plasma proteins by fractionation and is used as a substitute in dural surgery.Three new species ofRhizophlyctis, R. lovetti, R. fuscis, andR. hirsutus, as well asPhlyctorhiza variabilis and numerous other water molds have been trapped on this substratum in watered soil samples from India.This study has been supported by the U. S. Program in Biology, International Indian Ocean Expedition, and conducted at the Central Marine Fisheries Research Institute, Mandapam Camp, Madras State. I am very grateful to Dr.S. Jones, Director of the Institute, for research facilities and assistance.     

Observations on the Symmetry of the Shoot in Vicia faba and some Allied Species, and on the Transmission of some Morphogenetic Impulses

Axillary buds occur in unsymmetrical arrangements so that anynode must be either right- or left-handed. The two types occurin roughly equal numbers but are not randomly distributed. Thecondition of any node is determined partly by stimuli transmittedfrom the nodes below. The tissues of the stem can act as a filter,transmitting right- and left-handed stimuli with different degreesof efficiency. Although there are considerable interspecificdifferences in respect of these relationships, it is unlikelythat the actual state of right- or left-handedness of a nodeis subject to any direct genetical control. In this respectthe bud arrangements resemble phyllotactic spirals and differfrom most other right- or left-handed structures occurring inplants.