KEMP IN WOOL.

New Zealand Herald, Volume LXIV, Issue 19720, 20 August 1927, Page 18

KEMP IN WOOL.

EFFECT ON THE CLIP. Kemp is a straight, coarse, dull, opaque fibre, found mixed with woo] and depreciating the value of the clip in proportion to its abundance. It is often spoken of as " dead, diseased, and non-cellular " fibre, but, according to Professor J. A. Thompson, in the Scottish Journal of Agriculture, this is not quite an accurate description. Kemp has a thick central medulla, with hollow interspaces containing inclusions of air. Wool is made up of solid, spindle-shaped cortical cells, with no medulla and no air inclusions. Hence, wool allows, light to pass through as well as to be reflected from the surface, whereas kemp, being opaque in its core, simply reflects the light. Kemp has large external or cuticular cells with feeble serration and is non-elastic. Wool has small cuticular cells with conspicuous serration and ts elastic Kemp throws only for a certain time and is then shed woo! grows continuously and is not shed. There is in some Merino sheen an currence of kemp fibres with even thicker medulla than in ordinary hemp, and these are known as "dog-hair" and "gareand in general it may be said that the coarser the fibre the thicker the medulla.

It is not the case that the kemp fibres do not dye, but the presence of r : r in the medulla lessens the effectiveness of the dye. The included air prevents the colour showing in its perfection. It represents the retention of an ancestral hereditary character that has not been bred out. Also, the fibres tend to reappear under certain seasonal conditions, just likfc the large coarse hairs in horses and cattle and some other animals

The wool of the Merino represents the under or fur coat of mammals with two coats, the outer having disappeared, except in so far as it is represented by kemp fibres. Under domestication, the fine wool fibres have increased greatly in number and in crimpness, and, instead of haing shed, now grow continuously for the lifetime of the slier >. They surpass the kemp fibres, which were originally longer. In the new-born Merino ram there are two distinct coats, an outer coat "J coarse fibres, on the whole body, but sometimes most noticeable on head, limbs, and tail, and an inner coat of fine fibres. This is a recapitulation of ancient history. The two coats of the lamb represent an ancestral stage in the evolution of the Merino.