The structure of the anisotropic spheres which precipitate from isotropic pitch during pyrolysis. The structure of the spheres consists of a lamellar arrangement of aromatic molecules in parallel layers which are perpendicular to the polar axis of the sphere and which are perpendicular to the mesophase -isotropic phase interface . Note: The term Brooks and Taylor structure is recommended to describe the particular lamellar morphology of the spherules most commonly precipitated from pyrolysed pitch . The term honours the workers who first recognized the significance of carbonaceous mesophase to carbon science and technology and who first defined this spherical morphology . The term Brooks and Taylor structure does not cover all structures found in the spherical mesophase , because other lamellar arrangements have been observed.