Figure I-20
B, Higher magnification to show the cylindrical structures within the membrane of the mast cell granules. They are uniformly dense and of equal length. (X 60,000.) C, View of the cross-sections of the cylindrical structures. Each cylinder is formed by a single lamellar membrane which is wound into a scroll. The core of the cylinder contains an electron-dense material. (X90,000.) D, Cylinders in mast cell granules seen in cross-section. The core material (a) and a mass of granular material (b) are found within the granules. (X 99,000.)