Electron microscopy; proceedings of the Stockholm Conference, September, 1956 . electronmicrosco00euro Year: 1957 Fig. 1. Section through the ctiticlc of Liiinhriciis sp. whicli shows the layers of fibrils which lie adjacent to the epidermal cells. Cytoplasmic processes stretch between the cell surface and the outer membrane of the worm, and form a basket- weave pattern with the fibrils. The microvilli on the outer surface of the worm are seen at the top of the micrograph. Magnification 23,000. method whereby the protein molecules became orien- tated into the distinctive layered structure whi
Electron microscopy; proceedings of the Stockholm Conference, September, 1956 . electronmicrosco00euro Year: 1957 Fig. 1. Section through the ctiticlc of Liiinhriciis sp. whicli shows the layers of fibrils which lie adjacent to the epidermal cells. Cytoplasmic processes stretch between the cell surface and the outer membrane of the worm, and form a basket- weave pattern with the fibrils. The microvilli on the outer surface of the worm are seen at the top of the micrograph. Magnification 23,000. method whereby the protein molecules became orien- tated into the distinctive layered structure which has been shown to be a feature of this material. This work is still in a preliminary stage, but it has been found that the cuticle is composed of five regions. The region adjacent to the main body of the epidermal cells, which lie immediately beneath the cuticle, contains many evenly spaced folds of cytoplasm; these folds appear to taper into fine cytoplasmic processes which penetrate through the cuticle and are connected to the exterior membrane of the worm (fig. 1). In sections cut parallel to the surface of the worm, these processes are seen to be arranged in rows; they are usually about 700-1000 A in diameter and about 2000 A apart. Each row appears to be embedded in a ribbon of less dense material about 2500 A wide. It is possible that the processes correspond to the granular layer recorded by Read and Rudall (4) in replicas of the earthworm cuticle. Region 2, immediately above this lowest layer, con- tains fibrils about 200 A in diameter; there are about 4 layers of fibrils in this region. Region 3, which is about 5 // thick, is composed of about 18 layers of apparently unhanded fibrils. Transverse sections show that the fibrils are irregular in outline, in fact some are nearly square, and measure up to about 2000 A across (fig. 2). Longitudinal sections demon- strate that the fibrils are in layers, which confirms previous observations. Measurements have shown that the
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