Contributions to Australian Bryology. I. The structure, development and systematic affinities of Monocarpus sphaerocarpus gen. et. sp. nov. (Marchantiales)

1956 ◽  
Vol 4 (2) ◽  
pp. 175 ◽  
Author(s):  
DJ Carr
Keyword(s):  
Spore Germination ◽  
Systematic Position ◽  
Growth Substances ◽  
Structure Development ◽  
Single Genus ◽  
Mode Of Development ◽  
Western Victoria ◽  
The Relationship ◽  
North Western

A new thallose hepatic with characters intermediate between those of the Sphaerocarpineae (sensu Müller) and the section Caudiciformes of the Marchantiineae has been discovered on saltpans in north-western Victoria. The female thallus bears a single spherical involucre which has air chambers and specialized pores and contains a single sporophyte. The male plants have not been found. Details are given of the structure and mode of development of the involucre, air chambers, and pores, the early embryogeny of the sporophyte, spore germination, and the development of the thallus. The systematic position of the new plant (Monocarpus sphaerocarpus) is discussed and the literature on the relationship between the Sphaerocarpineae and other thallose hepatics is reviewed. The characters of Monocarpus are shown to support the view that phaerocarpus and allied genera should be placed within the Marchantiales rather than with the Jungermanniales. It is proposed to raise a new suborder of the Marchantiales, Monocarpineae, for the single genus, Monocarpus. Certain problems of morphogenesis are raised and it is suggested that the enciosure of more than one archegonium in an involucre is conducive to the inhibition of development of more than one sporophyte within the involucre. It is also suggested that growth substances released during meiosis in the sporangium control the post-fertilization growth of the thallus and involucre.

Studies on Leukemogenic and Sarcomagenic Viruses

1970 ◽  
Vol 28 ◽  
pp. 156-157
Author(s):  
Leon Dmochowski
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Morphological Properties ◽  
Mode Of Development ◽  
Relationship Of ◽  
The Relationship

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.

Leaf spot and dry rot of lettuce caused by Xanthomonas vitians (Brown) Dowson

1963 ◽  
Vol 14 (6) ◽  
pp. 778 ◽  
Author(s):  
DE Harrison
Keyword(s):  
Leaf Spot ◽  
Early Spring ◽  
Late Winter ◽  
Laboratory Studies ◽  
Dry Rot ◽  
Complete Destruction ◽  
Western Victoria ◽  
Valley Area ◽  
North Western

During the late winter and early spring of 1960, and again to a lesser extent in 1961 and 1962, many lettuce crops in the Murray Valley area of north-western Victoria were seriously affected by a disease characterized by blackening, dry rotting, and collapse of the affected leaves. The incidence of disease varied from about 10% up to practically complete destruction of some plantings. A yellow bacterium was consistently isolated from affected plants and proved to be pathogenic to lettuce. Laboratory studies have shown that the organism agrees closely with the recorded description of Xanthomonas vitians (Brown) Dowson, which has not, apparently, been previously studied in Australia.

Taxonomic studies on Archigetes Leuckart, 1878 (Cestoda: Caryophyllaeidae)

Parasitology ◽  
1965 ◽  
Vol 55 (3) ◽  
pp. 439-451 ◽  
Author(s):  
C. R. Keneedy
Keyword(s):  
Life History ◽  
Experimental Work ◽  
Nature Conservancy ◽  
The Family ◽  
Single Genus ◽  
Biological Characters ◽  
Taxonomic Studies ◽  
Relationship Of ◽  
Recent Experimental Work ◽  
The Relationship

Recent experimental work has indicated that species of Archigetes are capable of infecting and maturing in fishes in addition to tubificids.The genus Archigetes is re-defined on the basis of morphological and biological characters, with particular emphasis on recent life history studies. All species capable of neotenic development have been re-united in a single genus.A description of all species of Archigetes together with a key for their identification are included. New synonomies are discussed.The relationship of Archigetes to other genera of the family is briefly considered, and it is concluded that it forms the terminal stage in a series showing the attainment of neotenic development.I wish to thank Professor R. J. Pumphrey in whose Department the work was carried out, and Dr J. C. Chubb for advice and help in the preparation of this manuscript. I am also grateful to Professor K. Berg and Dr R. L. Calentine for the loan of specimens. The work was carried out during the tenure of a Nature Conservancy Research Studentship.

scholarly journals A note on the systematic position of the Bathynellacea (Crustacea, Malacostraca) using molecular evidence

2002 ◽  
Vol 71 (4) ◽  
pp. 123-129 ◽  
Author(s):  
Ana Isabel Camacho ◽  
Isabel Rey ◽  
Beatriz A. Dorda ◽  
Annie Machordom ◽  
Antonio G. Valdecasas
Keyword(s):  
Molecular Data ◽  
Systematic Position ◽  
Molecular Evidence ◽  
Gene Fragment ◽  
16S Rdna Gene ◽  
Internal Morphology ◽  
Mt 16S Rdna ◽  
Relationship Of ◽  
First Time ◽  
The Relationship

Molecular data for the mt 16S rDNA gene fragment of a bathynellacean is here presented for the first time and used to analyze the relationship of the group within the crustacean class Malacostraca (Arthropoda, Bathynellacea). Two contrasting views have classified the bathynelids as being either within the order Syncarida or in a separate super-order Podophallocarida belonging to the infra-class Eonomostraca, a disagreement based mainly on debates over external and internal morphology. The preliminary analyses offered here in question the placement of this Bathynellacea within the Syncarida, and suggest the need for a further study of relationships among the malacostracan groups.

Control of Amsinckia spp. by the pastures of north-western Victoria

1965 ◽  
Vol 5 (19) ◽  
pp. 500
Author(s):  
DJ Connor
Keyword(s):  
Seed Production ◽  
Subterranean Clover ◽  
Barrel Medic ◽  
Limited Application ◽  
One Year ◽  
The One ◽  
Western Victoria ◽  
Establishment Phase ◽  
North Western ◽  
Very High

Amsinckia is a serious weed in the wheat growing areas of north-western Victoria. It is successful in the inter-crop pastures, based upon barrel medic, because it grows faster than barrel medic in the cooler months of May to August. In addition, the rapid growth in height associated with the change from rosette to elongating phases ensures a height advantage over the pasture species when the flush of pasture growth does commence. Seed production by each Amsinckia plant is very high, and for this reason any competitive restriction obtained in one year is not necessarily reflected in the establishment phase of the next. Subterranean clover c.v. Clare is more competitive than barrel medic and was able to eliminate Amsinckia from the sward in two years. However it has only limited application in the pastures of north-western Victoria. A mowing treatment was carried out at the commencement of Amsinckia flowering, for this coincides with the beginning of rapid pasture growth. Regrowth produced a reversal of height relationships within the pasture and enabled barrel medic to shade Amsinckia BJ this treatment growth and seed production of Amsinckia were reduced by 99 per cent within the one season.

A Bird-Lover in the Mallee of North-western Victoria

1927 ◽  
Vol 27 (2) ◽  
pp. 69-75
Author(s):  
Charles Sullivan
Keyword(s):  
Western Victoria ◽  
North Western

scholarly journals Lateral Moraines of Glacier De Tsidjiore Nouve: Form, Development, and Implications

1983 ◽  
Vol 29 (102) ◽  
pp. 250-259 ◽  
Author(s):  
R. J. Small
Keyword(s):  
Complex Form ◽  
Current Mode ◽  
Sensu Stricto ◽  
Kinematic Wave ◽  
Glacial Erosion ◽  
Accumulation Zone ◽  
Mode Of Development ◽  
Form Development ◽  
The Relationship

AbstractThe relationship between supraglacial lateral moraines and lateral dump moraines at Arolla. Switzerland, is discussed. A detailed study of the lateral moraines of glacier de Tsidjiore Nouve reveals their complex form (as superimposed and nested ridges) and the current mode of development (possibly related to the passage of a kinematic wave). Sedimentological analysis indicates that much of the constituent debris is of supraglacial origin; it is transported either directly from the base of slopes flanking the Pigne d’Arolla ice-fall or via englacial septa comprising marginal sediment incorporated in the accumulation zone. A calculation of the volume of debris in the lateral moraines suggests that glacier de Tsidjiore Nouve has recently been more active in transporting and depositing supraglacial debris than in glacial erosionsensu stricto.

A Comparative Study of Metridium senile (L.) var. dianthus (Ellis) and a Dwarf Variety of this Species occurring in the River Mersey, with a discussion on the Systematic Position of the Genus Metridium

1934 ◽  
Vol 19 (2) ◽  
pp. 901-919 ◽  
Author(s):  
Ruth Rawlinson
Keyword(s):  
Comparative Study ◽  
Close Agreement ◽  
Systematic Position ◽  
Special Study ◽  
Metridium Senile ◽  
Typical Form ◽  
The Family ◽  
Single Genus ◽  
Sexually Mature ◽  
Dwarf Variety

1. A special study has been made of a small Metridiuni-like anemone found at Dingle, Liverpool, in comparison with the typical form of Metridium senile (L.) var. dianthus (Ellis).2. Penicilli, formerly believed to be absent from the acontia of typical M. senile, have been discovered in abundance in the young, but rarely in the adults. In young and sexually mature specimens of the Dingle anemone they are also abundant.3. There is close agreement between the anatomy of the Dingle form and the typical M. senile.4. A considerable amount of variation occurs in the Dingle anemone, as in M. senile var. dianthus and M. marginatum, Mime-Edwards.5. The resemblances and differences between the Dingle form and M. senile indicate that the former is a dwarf variety of the latter.6. The discovery of an abundance of penicilli in the acontia of young typical M. senile and mature specimens of the Dingle variety, in conjunction with the great amount of variation in the genus Metridium, suggests that a reconsideration of the systematic position of the genus is necessary and would justify either the restriction of the family Metridiidæ to the single genus Metridium, or else the fusion of the Metridiidæ with the Sagartiidæ. The sum of the evidence appears to lie in favour of placing the genus in a family by itself.

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