A common modification of the chief ramus of the Arthropod parapodium is the chela or nipper formed by the elongation of the penultimate joint of the ramus, so that the last joint works on it FIG.
As many as six pairs of appendages following the mouth may have an enlarged gnathobase actually functional as a jaw or hemignath, but a ramus is well developed on each of these appendages either as a simple walking leg, a palp or a chela.
It is divided into four stages, each one representing the degree of spiritual growth and karmic development at which the "chela" or disciple has arrived.
Although the way of the disciple or "chela" is always represented as long and difficult, it is said that as he proceeds, the transcendental faculties which arise to help him enable him to pursue the right course with ever increasing confidence and security.
As this last stage is approached the "chela" becomes less and less dependent on the guidance of traditions and scriptures.