Ref ID : 7558
E.C. Tatchell; An Ultrastructural Study of Extension and Contraction in Lacrymaria olor (O.F. Muller). Protistologica XVI(1):167-175, 1980
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The arrangement of the cortical structure of Lacrymaria olor was studied in extended and contracted organisms by means of light and electron microscopy. It was found that most of the extension occurred in the anterior quarter of the body, the neck region. This extension is associated with an untwisting of the spiral kinety and with an increase in the interkinetosomal spacing. In L. olor the sub-pellicular microtubules are very long and are linked to the pellicle by many cross-bridges. The postciliary microtubules are about 4.0 µm long and extend posteriad from their kinetosomal origin. The transverse fibres are composed of two groups of microtubules; one group consisting of three microtubules, the << trio >>, and the other group consists of six microtubules and is termed the << sextet >>. The trio microtubules follow a course almost perpendicular to the line of the kinety and the sextet extend forward from their origin for about 8 µm. The myoneme of L. olor exhibits a banded appearance in both extended and contracted states but the distribution of the constituent dark and light bands changes as the animal changes its length.