摘要:

Light and electron microscopic examinations have been made on a number of species previously attributed to the genusAmphipleuraKütz. As a result, two groups of species can be delimited, both of which warrant generic status. The genusBerkeleyaGreville is therefore extended to include the marine tube-dwelling species whileAmphipleurais confined to the freshwater free-living species. Comparison is made with species of the closely related genusFrustuliaC. Ag. and emended generic descriptions are given forAmphipleuraandBerkeleya.

ISSN:0007-1617    

DOI:10.1080/00071617500650011

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Infrared spectrum analysis and thin layer chromatography of cell walls of the sporophytic microthallus ofBryopsis plumosa(Huds.) C.Ag. and the sporophytic macrothallus ofDerbesia tenuissima(De Not. in Mor. et De Not.) Crouan frat. give evidence for the presence of a β-1,4-mannan as the main cell wall polysaccharide. Both macro- and microthallus ofPseudobryopsis myura(J.Ag.) Berth. contain mainly mannan.

ISSN:0007-1617    

DOI:10.1080/00071617500650021

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Ultrastructural details of envelope formation are described comparatively for several species of the genusTrachelomonas. The first-formed envelope component inT. oblongavar.punctataPrings. is an external “skin”. Next, a fibrillar layer is produced between the skin and the cell surface. Ferric hydroxide and manganese compounds are precipitated on this inner layer to form a thick envelope, species-specific in size, shape, ornamentation and collar characteristics. The original skin is then lost.

ISSN:0007-1617    

DOI:10.1080/00071617500650031

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Analysis of 100 cells ofMicrasterias laticepsNordst. from Guaratinguetá Co., São Paulo, Brazil, indicates that (1) size is not a satisfactory criterion for separating the varietieslaticepsandminorNordst., since a range of intermediates exists, (2) the attenuated shape of the basal lobe is not a character restricted to specimens otherwise agreeing with the description of var.minor, (3)M. laticepsvar.laticepsandM. laticepsvar.minorare synonymous, and (4) size range is a doubtful criterion for delimitation of infraspecific taxa of desmids.

ISSN:0007-1617    

DOI:10.1080/00071617500650041

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

After septum formation and dissolution of the zoosporangial apex wall inVaucheria fontinalis(L.) Christensen, a multi-flagellated zoospore is released and remains motile for a few hours. Settlement of the zoospore occurs with flagellar retraction, after which a cell wall is formed by peripheral vesicles. Subsequent germination initiates polarity and the development of vegetative filament growth.

ISSN:0007-1617    

DOI:10.1080/00071617500650051

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Investigations in the Shetland Isles in the summer of 1973 have produced many new algal records for the area, including several of particular interest for the British flora in general. Those discussed here areBolbocoleon piliferumN.Pringsh.,Blastophysa rhizopusReinke,Ochlochaete feroxHuber,Asparagopsis armataHarv. (theFalkenbergia-phase occurs in Shetland) (by I. Tittley);Audouinella spetsbergensis(Kjellm.) Woelk.,Kallymenia reniformis(Turn.) J. Ag. (with impacted cystocarps and carpospores developing in situ) (by M. Guiry);Cladophora pygmaeaReinke (new to the British Isles) andEndodictyon infestansGran (suggested to be a plethysmothallus ofEctocarpus) (by G. Russell).

ISSN:0007-1617    

DOI:10.1080/00071617500650061

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The scanning electron microscope has assisted in the identification of three forms of the genusFragilariathat occur in the late-glacial assemblages of some Scottish lochs. Scanning electron microscopy, light microscopy and reference to type material have confirmed the differences betweenF. lapponicaGrun.,F. pinnataEhrenb. andF. ellipticaSchumann.

ISSN:0007-1617    

DOI:10.1080/00071617500650071

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The discharge of thermal effluent from a power station has been shown to cause an increase in the standing crop size of the epiphyton associated withScirpus validus. As a result the mean primary productivity, as measured by the14C method, increased, primarily because of the large spring and summer maxima caused byOedogoniumandSpirogyra, Epithemia turgida, Mougeotia, Amphipleura pellucida, Nitzschia fonticolaandRhopalodia gibbawere apparently detrimentally affected by the thermal effluent. The algal populations in the non-heated areas did not appear to be photosynthesising at optimum temperatures, while the continuous flow of heated water appeared to cause a decrease in photosynthetic efficiency of the algae in the heated area.

ISSN:0007-1617    

DOI:10.1080/00071617500650081

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The presence ofPappomonas lepidaTangen is demonstrated in South Africa for the first time and its coccoliths shown to be more scale-like at the base than has previously been recognised. Somewhat similar but differently arranged appendages are used as the basis for a new genusPappomonas, well represented in South Africa but also present in West Greenland. The type speciesP. flabelliferasp. nov. is described and illustrated with special reference to the protoplasmic appendages and aspects of coccolith structure in both calcified and uncalcified specimens. Some preliminary conclusions on coccolith morphology are outlined but more detailed discussion is deferred until a second species ofPappomonas, so far known only from West Greenland, has been described.

ISSN:0007-1617    

DOI:10.1080/00071617500650091

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

ISSN:0007-1617    

DOI:10.1080/00071617500650101

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor