This is hair from a dark red cow. Many older patterns, including some of Skues' patterns, and of course Cutcliffe´s specify certain types of cow hair: The main point here, is that only the shed hair, which the animals shed in winter, and may be found hanging on fences etc, is really soft enough to use. Hair direct from the cow is usually too coarse and wiry.Some dressers even went to the trouble of collecting bird´s nest linings which used such hair, among other things. The hair from young black bullocks, when shed, has a reddish purplish translucence. Skues used this for a BWO nymph. Cutcliffe used cow hair quite extensively, as the colours and shades fitted well with his cock hackle colours and shades, which he bred himself for fly-dressing purposes. None of these feathers are now easily available.
(http://img855.imageshack.us/img855/7000/redcow.jpg) (http://imageshack.us/photo/my-images/855/redcow.jpg/)
I have a fair collection of this stuff from various breeds and colours. Too coarse for most things.