"An interesting side-point is the source of the word palmered, I am sure many reader will be acquainted with its origins, but for those readers who are not, please allow me to explain. In bygone days in England an alternative name for a pilgrim was a palmer. the word related to the wanderings of these holy aspirants. In the early days of fly tying a common fly pattern was based on a hairy caterpillar, which hairy caterpillar it represented I have no idea, but safe to say this was a popular imitation at least according to the available literature from the time. The hackle wound generously around the hook gave a good impression of the hairy caterpillar. Anyone who has seen big hairy caterpillars will acknowledge that they appear to wander wherever they fancy. The early tyers equated these wanderings of the caterpillar to that of a pilgrim or palmer, hence the words palmering and palmered."
Ian Moutter "Imitative Fly Tying" Rick
