doi: 10.1093/icb/9.1.1pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1969 by the American Society of Zoologists
doi: 10.1093/icb/9.1.2pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1969 by the American Society of Zoologists
doi: 10.1093/icb/9.1.4pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1969 by the American Society of Zoologists
doi: 10.1093/icb/9.1.5pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1969 by the American Society of Zoologists
doi: 10.1093/icb/9.1.70pmid: N/A
Article PDF first page preview Close This content is only available as a PDF. © 1969 by the American Society of Zoologists
doi: 10.1093/icb/9.1.71pmid: N/A
Abstract The location and function of the five or six sets of silk glands of Araneus diadematus (Cl) are discussed. The structure and function of the three major parts of the ampullate gland indicate a synthesizing, collecting, and possibly structuring section. Two methods of stimulation of the ampullate gland, namely emptying the gland and cholinergic stimulation, are known. In both cases there is an initial secretory stage followed by rapid synthesis of new protein. The sequence of events following stimulation by both methods is described, based on studies of the incorporation of labeled protein and RNA precursors and on autoradiographic studies. Characteristic changes occur in the fine structure during the stimulatory cycle. Several experiments show that the spider has information on the amount of silk available to it for use in web-building. A structure which may act as a biological transducer has been located in the ampullate gland. This content is only available as a PDF. © 1969 by the American Society of Zoologists
doi: 10.1093/icb/9.1.81pmid: N/A
Abstract Static forces in spider webs are discussed in terms of the changes they produce in the position and shape of the web filaments. Material properties of the silks are related to the structure and functions of the spider webs. Gravity and wind forces are considered, but localized forces are particularly interesting. They may be used to measure by simple optical methods the forces and energies involved in different routine operations and emergencies. Rapid disturbances of the filaments create two kinds of signals which circulate separately through the web. Their speeds are given and their time development describes the nature and location of the disturbing source. This content is only available as a PDF. © 1969 by the American Society of Zoologists
FRIEDRIC, VICTOR, L.;LANGER, RUDOLPH, M.
doi: 10.1093/icb/9.1.91pmid: N/A
Abstract Sticky silk from webs of the spiders, Uloborus diversus and Filistata arizoniciis,were examined by election microscopy. The silk of U. diversus contains long fibrils, 200 –300 A˚ in diameter, consisting of an electron-dense central filament, 30 –60 A˚ across, embedded in a lighter matrix. Transverse banding is distinguished in the matrix at intervals from over 200 to less than 50 A˚. Similar features are observed in the silk of F. arizonicus. Extended fibrils have an altered structure. This content is only available as a PDF. © 1969 by the American Society of Zoologists
LANGER, RUDOLPH, M.;EBERILARD,, WILLIAM
doi: 10.1093/icb/9.1.97pmid: N/A
Abstract Methods for photographing spider silk without intense light or a reflective coating have been devised which permit appropriate exposure for both the spider and the thread in the same picture. Patterns of light scattering which may prove useful in other studies were observed. This content is only available as a PDF. © 1969 by the American Society of Zoologists
doi: 10.1093/icb/9.1.103pmid: N/A
Abstract Araneomorph spiders from many different families show some regional differentiation of the duct which carries the drag-line silk, but only in the orb-web spiders is there a well-defined control valve. This valve, and its associated muscles, is described for Araneus diadematus (Argiopidae), an ecribellate spider, and is compared with that found in Uloborus octonarius (Uloboridae), a cribellate spider. It is suggested that the remarkable similarity between the valves in these two groups implies evolutionary convergence. Some evidence is presented which suggests that variations in body pressure are used to control the drag-line spinning, at least in the more primitive Araneomorphs. This content is only available as a PDF. © 1969 by the American Society of Zoologists
Showing 1 to 10 of 23 Articles