Further Observations on the Fine Structure of Chrysochromulina Chiton With Special Reference to the Haptonema, ‘Peculiar’ Golgi Structure and Scale Production

1967 ◽  
Vol 2 (2) ◽  
pp. 265-272
Author(s):  
IRENE MANTON
Keyword(s):  
Fine Structure ◽  
Special Reference ◽  
Internal Structure ◽  
Similar Species ◽  
Scale Production ◽  
Related Genus ◽  
Fixation Methods ◽  
Close Resemblance ◽  
Golgi System ◽  
Golgi Structure

A more detailed study of ‘peculiar’ Golgi structure in this organism has been attempted than in any similar species, using modern fixation methods. Where comparisons are possible there is close resemblance to the related genus Prymnesium, to a degree sufficient to suggest that this particular type of Golgi system is likely to be a major phyletic indicator for the class Haptophyceae. Certain stages of scale production have been traced and some developmental aspects of the whole system are discussed, though full interpretation is deferred. Some additional features of haptonema structure are described for the sake of completeness in characterizing the particular strain of the species under investigation. These include information on the internal structure of the haptonema tip.

scholarly journals Further Observations on the Fine Structure of Chrysochromulina Minor and C. Kappa with Special Reference to the Pyrenoids

1961 ◽  
Vol 41 (2) ◽  
pp. 519-526 ◽  
Author(s):  
I. Manton ◽  
G. F. Leedale
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Special Reference ◽  
Direct Evidence ◽  
Living Cells ◽  
Marine Plankton ◽  
Thin Sections ◽  
Golgi Structure

Chrysochromulina minor and C. kappa have been re-investigated by means of electron microscopy of thin sections to add details of the microanatomy of pyrenoids and haptonemata, and by anoptral contrast light microscopy to study pyrenoids in living cells. In both species the pyrenoid is in the form of a diverticulum projecting from the centre of the inner face of a plastid and, in C. minor, strongly flexed to lie along it. In C. kappa the pyrenoid is commonly enveloped by the nucleus which may conceal it entirely from view in life. Some details of the behaviour of the surface membranes of plastids and pyrenoids in relation to that of the nucleus are given. The haptonema structure in both species is shown to be comparable to that of others in which this appendage is much longer, though an occasional variant with eight instead of seven central fibres or tubes has been encountered in C. kappa and is demonstrated. The presence of ‘peculiar’ Golgi structure is reported for both species and demonstrated for C. kappa. Some direct evidence indicating an internal origin of scales from vesicles is demonstrated in C. minor. Finally a summary is given of salient structural criteria for all the described species attributed to this genus from the marine plankton, the closest agreement as regards pyrenoid structure in the two species under investigation being with C. chiton.

Fine structure of prolactin pituitary adenoma with special reference to annulate lamellae

1979 ◽  
Vol 46 (1-2) ◽  
pp. 163-166 ◽  
Author(s):  
M. Scanarini ◽  
R. Giordano ◽  
S. Mingrino ◽  
N. Pennelli
Keyword(s):  
Fine Structure ◽  
Pituitary Adenoma ◽  
Special Reference ◽  
Annulate Lamellae

Observations on Scale Production in Pyramimonas Amylifera Conrad

1966 ◽  
Vol 1 (4) ◽  
pp. 429-438
Author(s):  
IRENE MANTON
Keyword(s):  
Developmental Stages ◽  
Basic Problem ◽  
Scale Production ◽  
Body Type ◽  
Primary Object ◽  
Large Numbers ◽  
Golgi Structure ◽  
Flagellar Scales ◽  
Duct Opening ◽  
Narrow Duct

Scale production has been studied after glutaraldehyde fixation with the primary object of tracing the source of flagellar scales which this species is known to possess (Manton, Oates & Parke, 1963). Large numbers of all types of flagellar scales, unmixed with body-type scales, are detectable at all times, stored in an orderly arrangement within a vesicular scale reservoir of characteristic morphology which is described. These scales are liberated through a narrow duct opening to the cell exterior near the flagellar bases. This duct is thought to be temporary and subject to reformation with minor change of site, since open ducts are more frequently encountered in darkness than by day; some putative developmental stages are illustrated. Observations on other details of scale production include demonstration of the formation of all types of body scales within the Golgi cisternae, sometimes together with a few flagella-type scales. The larger body-type scales are uniformly oriented within the Golgi cisternae in relation to the position of the subtending endoplasmic reticulum. This orientation is lost before liberation to the cell surface, which occurs from moderate-sized detached vesicles in an unknown manner. The implications of these findings for an understanding of Golgi structure and of the basic problem of scale arrangement on the receiving sites are discussed in a preliminary way.

A Discussion on solar studies with special reference to space observations - The manifold structure of the chromosphere and corona

1971 ◽  
Vol 270 (1202) ◽  
pp. 77-80 ◽  
Keyword(s):  
Magnetic Field ◽  
Fine Structure ◽  
High Resolution ◽  
Field Strength ◽  
Special Reference ◽  
Velocity Fields ◽  
Field Patterns ◽  
Uniform Region ◽  
Determining Factor ◽  
The Magnetic Field

Although the photosphere is a uniform region for scales greater than the granulation, the fact that the magnetic field strength falls off less sharply than the gas pressure leads to strong magnetic influence at greater heights in the solar atmosphere. This magnetic influence leads to non-uniformity and fine structure in the chromosphere and corona. The existence of such structure has been deduced mostly from measurements of photospheric phenomena; in particular, from measurements of photospheric velocity fields (Leighton, Noyes & Simon 1962) and of photospheric magnetic fields (Bumba & Howard 1965). The determining factor would thus appear to be in the photosphere; but visible effects only are produced in the chromosphere and corona. In recent years, high resolution filter photography has enabled us to recognize different regions of the chromosphere, where qualitatively different structure is associated with distinct magnetic field patterns. This progress has been possible because of better Lyot filters, better films and better observing sites; the spectroheliograph has always been limited for high resolution work by the finite slit width and the difficulty of accurate guiding during the long exposures.

A Taxonomic Revision of Fern Genus Pseudocyclosorus (Thelypteridaceae) from China and the Pan-Himalaya Region, with Special Reference to the Identity of Pseudocyclosorus stramineus

Phytotaxa ◽  
2019 ◽  
Vol 424 (4) ◽  
pp. 197-216
Author(s):  
ZHONG-YANG LI ◽  
XIAN-CHUN ZHANG ◽  
ZHEN-LONG LIANG ◽  
JIE LI
Keyword(s):  
Special Reference ◽  
Species Delimitation ◽  
Morphological Study ◽  
Taxonomic Revision ◽  
Morphological Characters ◽  
Morphological Features ◽  
Similar Species ◽  
Spore Morphology ◽  
Distribution Map ◽  
New Synonyms

The fern genus Pseudocyclosorus (Thelypteridaceae) from China and the Pan-Himalaya region is revised based on morphological study. Reduced basal pinnae, angles between costule and costae, and glands/hairs on abaxial surfaces/indusia are considered as the most diagnostic morphological characters for species delimitation. Genus Trigonospora was excluded from genus Pseudocyclosorus. This segregation is supported by multiple morphological features. Eight species were recognized here, namely Pseudocyclosorus tylodes, P. pseudofalcilobus, P. falcilobus, P. subochthodes, P. stramineus, P. ornatipes, P. esquirolii and P. canus. Twenty-one names were reduced as new synonyms. One name (P. duclouxii) was considered a dubious species. A key to these eight species, their descriptions, spore morphology and distribution map of each species are given.         Pseudocyclosorus stramineus was a long overlooked species, which has always been misidentified as other similar species, and was wrongly reduced as a synonym of P. duclouxii. Here based on morphology characters, the identity of P. stramineus as a species was reclaimed. A more detailed description with photographs and illustrations, and its whole distribution range are given here.

Morphological study of noradrenaline innervation in the caudal raphe nuclei with special reference to fine structure

1981 ◽  
Vol 203 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Hiroshi Takagi ◽  
Kazumi Yamamoto ◽  
Sadao Shiosaka ◽  
Emiko Senba ◽  
Kenichi Takatsuki ◽  
...  
Keyword(s):  
Fine Structure ◽  
Special Reference ◽  
Morphological Study ◽  
Raphe Nuclei ◽  
Raphé Nuclei
Sign in / Sign up

Export Citation Format

Share Document