von Wielowiejski (1882), of cells similar to those of the fat-body, containing a substance that undergoes oxidation.
The luminous organs of these beetles consist of a specialized part of the fat-body, with an inner opaque and an outer transparent layer.
This cavity contains an irregular mass of whitish tissue, the fat-body, consisting of fat-cells which undergo degradation and become more or less filled with urates.
The fat-body is therefore the seat of important metabolic processes in the hexapod body.
This latter, as well as the heart and the walls of the blood spaces, arises by the modification of mesodermal cells, and the body cavity is formed by the enlargement and coalescence of the blood channels and by the splitting of the fat body.