[Cuticular collagen in Lumbricus sp. Ultrastructure of native fibrils and of precipitates obtained from acetic solutions].

The paper describes the techniques used to isolate the cuticular collagen fibrils of Lumbricus sp. As revealed by electron microscope examination the isolated fibrils, positively and negatively stained, are aperiodic and appear made up of bundles of filaments (30 A) with an helicoidal arrangement. A filamentous network has been precipitated from the acetic solutions of cuticular collagen. The network exhibits an electrondense cross-striation every 3 000 A.