ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04450.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04451.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

SYNOPSISThe Golgi apparatus of the epidermal club cells of the catfishSynodontis Schallcan be revealed by the classical methods and is formed of chromophobe vacuoles surrounded by chromophil walls. At certain phases the vacuoles are either missing, or they may be submicroscopic and thus beyond the limits of resolution of the light microscope.The Golgi apparatus undergoes marked morphological changes and hypertrophy according to the age and the physiological condition of the club cell.In the early stages of the growth of the club cell, hypertrophy of its Golgi apparatus takes place by the production of a large number of spherical bodies which are mostly dictyosome‐like. Further additions to the Golgi material are mainly in the form of long filaments which spread out into the cell cytoplasm and enclose at intervals spherical inner chromophobe vacuoles. There is evidence that some of the filaments may develop from the early‐formed dictyosomes by the lateral extension of the osmiophil material.With the further growth of the club cell, the Golgi vacuoles change from spherical to oval and later to more elongated forms, giving the Golgi material the conventional canalicular picture. Later the Golgi apparatus undergoes fragmentation, the fragments being found close to the cell periphery.In some of the club cells the Golgi fragments are seen in close contact with vacuoles which are interpreted as of secretory nature. These vacuoles are of common occurrence in the peripheral cytoplasm of most of the larger club cells.The secretion referred to arises in the cell cytoplasm in the immediate vicinity of the osmiophil material and not inside the Golgi chromophobe vacuo

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04452.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

SYNOPSISThe ultrastructure of most of the pineal eye cell types is surveyed, excepting the cell clusters (lens‐bodies) occurring in the lens and sometimes in the lumen. Greatly improved technique and apparatus resulted in interesting and new phase‐contrast observations, especially as regards the occurrence of ganglion cells in the nerve‐fibre layer and on the appearance of the sensory cell appendages. It is found that there are two types of sensory cells in the pineal eye; most of them are cone‐like cells very similar to the lateral eye cone cells. The pineal eye sensory cells have inner and outer segments, the former often having dense particles, mitochondria and oil droplets, and the latter, rod disks. The two segments are connected by a connecting cilium with ciliary filaments. The pineal eye sensory cells are obviously ciliary derivatives, and the possibility is discussed that they may develop from cilia seen to protrude through the microvillous border of the organ's lumen. It is further suggested that the outer segments may be transitory structures, or changeable in appearance.Structures resembling the two types of synapses described for the lateral eye are reported. The ultrastructure of the nerve‐fibre layer of the pineal eye is described.The inclusions and structure of the sensory cells and of pigment cells at various levels in the organ are described, and the nature of a coagulate which may represent a secretion or fluid occurring in the lumen is discussed. The fine structure of the pineal eye lens cells is described, and the absence of an inner limiting membrane noted.The possible functional significance of the above observations is

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04453.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

SYNOPSISChange of the tube length or of the separation of the elements of the objective can be used to eliminate the image degradation caused by incorrect refractive index or thickness in the object space. These can be in either the cover‐slip or the immersion oil. The quantitative relations were studied. The method of compensation is effective even over an extreme range.A simple formulation was found to express the toleration of an observer to image degradation due to variation of the aforementioned factors from the designed optimum. This tolerance, expressed as*** + T(Δx) is affected only by the numerical aperture of the objective; T(Δx) = k(N.A.)−v. The two parameters,vandk, are significant, the latter being a measure of the strictness of the quality criterion. Graphs are presented from which these tolerances can be

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04454.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

SYNOPSISSome new and interesting Diatoms from the Jog‐Falls are described and illustrated. One species ofAchnanthesis re‐interpreted and five varieties are described as new to scie

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04455.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

摘要:

SYNOPSISA description is given of the fine structure of two marine plankton diatoms from New Zealand:Stepkanopyxis orbicularisWood andBiddulphia mobiliensis(Bailey) Grunow. Three‐dimensional structure has been elucidated by photogrammetric means from stereoscopic pairs of electron micrographs.A hypothesis regarding the mechanism of growth in the girdle ofStephanopyxisis suggeste

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04456.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04457.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY

ISSN:0368-3974    

DOI:10.1111/j.1365-2818.1959.tb04458.x

出版商:Blackwell Publishing Ltd    

年代:1959

数据来源: WILEY