These three concentric tissue mantles are evidently formed by the conjoined bases of the leaf traces, each of which is composed of the same three tissues.
The former is often a rich oil-gas, stored in steel reservoirs under the coaches at a pressure of six or seven atmospheres, and passed through a reducing valve to the burners; these used to be of the ordinary fish-tail type, but inverted incandescent mantles are coming into increasing use.
The heart gives off posteriorly a second median vessel which divides almost at once into a right and a left half, each of which again divides into two vessels which run to the dorsal and ventral mantles respectively.
In course of time various plaids or mantles are assumed, and in Babylonia the goddesses were the first to have both shoulders covered.
The Babylonian temples received garments as payment in kind, and the Egyptian lists in the Papyrus Harris (Rameses III.) enumerate an enormous number of skirts, tunics and mantles, dyed and undyed, for the various deities.