37: Chain—a series of seven globes or worlds which form the field of evolution during the planetary cycle or manvantara.  The first three of these globes—generally known as A., B. and C. form a descending arc, the densest physical matter of the descent being reached in the fourth globe, D, of which our earth is an instance.  The fifth globe, E, on the ascending arc (correspondence to C on the descending arc) usually belongs to the astral plane, and the sixth and seventh F and G (correspondence to B and A on the descending arc) to the Rupa and Arupa levels of the mental plane; these therefore are invisible to ordinary sight.