The fourth point to be noticed was the change of designation from "Lodge" to "Chapter. "The word" Chapter " derives from Caput, head. The reason for the change of name lies, however, much deeper than in the fact that the Royal Arch stands at the head or summit of the Craft. It has reference in a twofold way to the capitular rank and consciousness of the Arch Mason himself. In virtue of his headship or supremacy over his material nature he has passed beyond mere Craftwork and governing the Lodge of his lower nature, which he has now made the docile instrument and servant of his spiritual self. Henceforth his energies are employed primarily upon the spiritual plane. The "head" of the material organism of man is the spirit of man, and this spirit consciously conjoined with the Universal Spirit is Deity's supreme instrument and vehicle in the temporal world. Such a man's physical organism and brain have become sublimated and keyed up to a condition and an efficiency immensely in advance of average humanity. Physiological processes are involved which cannot be discussed here, beyond saying that in such a man the entire nervous system contributes to charge certain ganglia and light up certain brain-centres in a way of which the ordinary mind knows nothing. The nervous system provides the storage-batteries and conductive medium of the Spirit's energies just as telegraph wires are the media for transmitting electrical energy. But the true Master Mason, in virtue of his mastership, knows how to control and apply those energies. They culminate and come to self-consciousness in his head, in his intelligence. And in this respect we may refer to a very heavily veiled Scriptural testimony, the import of which goes quite unperceed to the uninstructed reader. The Gospels record that the Passion of the Great Exemplar and Master concluded " at the place called Golgotha in the Hebrew tongue; that is, the place of a skull"; that is to say it terminated in the head or seat of intelligence and in a mystery of the spiritual consciousness. The same truth is also testified to, though again under veils of symbolic phrasing, in the reference to the sprig of acacia planted at the head of the grave of the Masonic Grand Master and prototype, Hiram Abiff. The grave is the candidate's soul; the sprig of acacia typifies the latent akasa (to use an Eastern term) or divine germ planted in that soil and waiting to become quickened into activity in his intelligence, the " head " of that plane. When that sprig of acacia blooms at the head of his soul's sepulchre, he will understand at one and the same moment the mystery of Golgotha, the mystery of the death of Hiram, and the meaning of the Royal Arch ceremony of exaltation. It is a mystery of spiritual consciousness, the efflorescence of the mind in God, the opening up of the human intelligence in conscious association with the Universal and Omniscient Mind. It is for this reason that the cranium or skull is given prominence in the Master Mason's Degree.