HOW WOOL GROWS

Manawatu Times, Volume XLIX, Issue 2312, 3 December 1925, Page 9

HOW WOOL GROWS

length and density,

In the “Farmers’ Weekly,” a South African journal, an interesting correspondence has arisen through a seldom thought of point. It is in relation to tho density of the wool and the surface area of the skin of the sheep. , , It was asked; “Where do sheep get the extra w.ool to keep the skin densely covered as they grow from lambs into full-grown sheep? Take a lamb a month old; then take ft again at six months of age. The skin is,, say three times as groat in area at six months old, and yet 1* just as densely covered With wool." Somebody may say that extra wool fibres have grown as tho area of th o skin increased, but have they? Shear -that lamb at six months old; let it run for a year before Die next shearing: tho area of its skin is again almost doubled, but the wool is denser than when • shorn as a lamb. Now shear it again, and examine the, fleece; all fibres are fully-grown from skin to tip of staple. If extra fibres have grown to keep the increasing area of skin covered with the same density of wool one would cxpoct to find all lengths and ages of wool, from fibres just beginning to come through tho skin, to full-grown twelve months’ fibres.” Tho problem was referred to Professor J. E. Diierdcn, of the Qrootfontcin Agricultural College, who. In the course of a lengthy reply, naively acknowledges that it took three weeks of close investigation to prepare an answer. . . , . Dealing with the point raised m connection with the growth of extra fibres, the professor shows that such are in actual fact constantly breaking through the skin. He says; “I have gone to the trouble to examine fibres from scores of samples of wool of all ages, from lambs’ wool to that shorn from sheep several years old. The ‘staples have been opened out and combings made from both ends; these have then been mounted in Canada balsam and examined under tho microscope. In every case new fibres of different lengths have been found among tho combings, more plentiful in combings from the wool of lambs and young sheop than in those from old sheep. These now fibres are readily distinguished by the fact that one end is tapertng and pointed, while fibres previously shorn and extending the whole length of the staple are truncate or cut off at both ends. Thus those is no question that new woo., fibres of different ages appear in the fleece as the lamb grows to maturity.”