WOOL AS AN ORGANISM.

Press, Volume LX, Issue 11511, 18 February 1903, Page 5

WOOL AS AN ORGANISM.

By Professor F. H. Bowman, in the "Live Stock Journal." Few persons who look at a s'.ieep and admire the soft woolly coat with which it is covered, or who examine a fleece after its removal from the slieep's back, have any idea of the complexity as an organism of" each fibie of which the fleece is composed, and how much the eharacteristies and quality of this organism are varied Dy the breed" and culture of the sheep, the attention which is paid to it in health or sickness, and alao by its environment. These fibres differ in thickness and length in different parts of the fleece, and also in that peculiar property of wool which consists in the hbie possessing a wavy or curly appearance, by which it may at ciinoe be distinguished from hair. In many fleeces hairs are found, especially just at those parts where the edges of the fleece terminate, such as the neck and legs, but when they are found elsewhere they are indications of want of breed or careless attention, and deteriorate the value of the wool accordingly. If a single fibre is selected and drawn through the fingers in the direction from the point of attachment to the free end of the fibre it will slip easily along, as if it was a smooth cylindrical rod, very flexible and about the same diameter from end' to end, and if the' wool has not been washed the fibre is found to be covered with a greasy, odourless substance which ad-he-res to the surface, called suint. The thickness of the fibre and its regularity in this respect, as well as in the amount of curl in its length and the amount of the adhering fat , depends largely upon lue breed of sheep from which it is obtained. If the fibre is drawn through the finger in the direction from the free end to the point of attachment, an apparent roughness is encountered, whicn indicates that the surface has a serrated structure, like the teeth of. a saw, which in the grease cannot be seen. , If tho ,?rease is removed by washing with, weak alkali the cause cam easily be seen, even with the naked eye in coarse fibres, as the whole surface of the fibre looks like a very small ivory rod covered all over the surface with small ring-shaped scales like tho markings on the stem of a, palm tree, or the scales on a fish, and like the slates on a house top, having all the free margins of the scales or tiles pointing in one direction, viz., from the loot to the point or free end of the fibre. The brightness or lustre of these scales and the number and disposition of them upon the surface of the fibre are influenced by the breed of the sheep, its envoronment, and the care and attention bestowed upon it. . . ■ . When a microscope is used these surface markings or scales are distinctly visible, and then the lustre of the scales and their number and disposition can be studied with the greatest ease. So distinctive are these features that a classification of the different breeds of sheep may be founded upon them, and by this means cheep may be divided into two kinds: 1. The long-wooled sheep, in which the fleece is distinguished, by the great length of the fibres, the high lustre or brightness which they exhibit With few scales and little curl. The standard type of this class is the Lincoln or'the Leicester sheep. 2. The short-wooUed sheep, where the fleece is very fine and curly, and the fibres possess small lustre and the scales on the surface are numerous. The merino sheep is the'type of this class, and in this country the Southdown. The outward appearance of the wool fibre which can thus be studied under the microscope is only the indication of a much more complicated structure wnich ; is revealed when the fibre is examined in* longitudinal or cross section, like a plank cut out of a tree or a elice from a cucumber. Before this complexity and its cause can be. understood it is necessary U> consider the origin and growth of the fibre and its relation to the general economy and organism of the The fibre is nn appendage of the skin, out of which it grows, and which it is connected in vital organic'continuity, and its growth and! structure are intimately related to the structure of the skin of which it forms an integral part. Without entering into unnecessary anatomical details, it may be. shortly stated that the skin of all the ulgher vertebra-ted animal's is formed of four strata or layers. Two of these layers form the outer skin, called the epidermis, and' two the deeperseated dennis, or true skin, by which the outer skin is brought into organic connection with the body, and from which it originates. Wool, hair, and even the feathers of birds, are similar to each other in their essential features, and are all produced In the same- manner, having their origin in a sac-shaped depression in the skin, in the bottom of which tnere is an increased production of epidermic or skin cells. All parts of the fibre are, indeed, only modifications of the various parts of the skin, which have had a' vertical, rather than, a horizontal, determination given to them. This sac or follicle is formed In the substance of the dennis, and is supplied with abundance of blood by a special distribution of vessels in ita waif. These vessels are continued as a fine network a short distance beyond the bulb or root which forms the bottom of the sac, and others feed the cells until they are fully developed and incorporated an determined order into the substance of the fibre, the various parts of which correspond, layer.by layer,.with the structure of the skin. As the fibre is formed it rises upwards and outwards towards the surface of the skin, the component cells of the various layers becoming more firm and consolidated, until they receive their final form and pass out of the follicle beyond the surface of the skin. The walls of the follicle are also supplied with suitable glands, which secrete the suint cr fat, which is conveyed by dues to lubricate the surface of the fibres, and prevent injury to the dedicate parts of the structure. The popular idea that a wool or hair fibre is a hollow tube is quite an error, as the wool fibre is Been, when examined in st-ction, to consist of a more or less soiid substance forming the shaft of the fibre. The central longitudinal part of the fibre round which the other parts are centrically arranged is usually in hairs composed of more or less roundsd cells, which are less closely packed together than the other portions," but in the typical wool fibre these are ..generally absent, and their place taken by the elongated spindle-shaped cells which form the substance or cortical part of the hair, and upon which its strength and elasticity depend. The outside of the fibre or covering of this cortical substance consists of flattened cells, which have a horny consistency, and form the cuticle or surface scales) which give the serrated appearance and surface markings already mentioned. In the most perfect forms of wool fibre and those which are of the greatest value to the manufacturer, we find the central medulla or pith with i*s round cells always absent, and tha fibre 5 also colourless, as the pigment upon which tho coCour of any fibre or hair depends is always developed in this portion of the fibre.. .The. presence of; colouring matter in the

result of degradation arising from want of due care and attention, which causes reversion to more primitive forms. Apart from the structure of the cortical portion, which is the most important as forming the largest part of the fibre, the nature of the external plates or scales which cover the surface is of the utmost value to the manufacturer. It 19 upon the character of tliese that the lustre or brightness of the fibre and its faking propeities—which play so large a part in the making of cloth—depend. While on the sheep's back, all the fibres being arranged in one direction, so that none of the free margins of these scales oppose each other, there is no tangling or felting action, and this is further prevented by the suint which enswathes each fibre and permits them to pass freely over each other. When, however, the wool is in the fleece, ar.d the fleece itself broken up into individual fibres in the process of manufacture, this unity of direction no longer pertains and the fibres come together in opposite directions, and so the opposing free margins of the scales interlock ana become embedded in each other. It ia important that the farmer should remember this, because, after sheep have been washed and the suint which protecta the fibres removed, there is always danger that restlessness on the part of the sheep, which may arise either from irritation of the skin or "other causes connected with its health and cleanliness, may greatly deteriorate the value of the fleece by the formation of cots, which are not natural growths, but. are artificially produced. In one sense all our high-bred sheep are themselves artificially produced, and may be regarded as manufactured articles, of which the old primitive sheep of prehistoric ages was the raw material, and the process' of manufacture has been carried on through long agies by the careful selection of sire and dam and the introduction of different types or strains so as to secure the desired results. All such artificial creatures are jn a perpetual state of unstable equilibrium, and nothing hut unceasing attention and care of the animals can maintain the highest standard of perfection for long. This is clearly seen in the constant necessity that there is to weed out any reversions which may occur, and keep up the quality by the proper introduction of new blood from time to time. Leaving out for the time being the value of the carcase as food—which even in our colonies has assumed a very important position since the facilities for ocean transport and communication have been rendered so easy and safe—and looking at the wool alone, it is well to remember that the lower the price the greater is the .necessity for maintaining the highest standard, because this will give that particular clip or mark a preference in the market, and secure the highest price that is attainable for that class of wool. It is fortunate that whatever causes lead to an increased quality in the meat react on the wool and improve it also, although these changes are not always concurrent in regard to size and weight, as a large and heavy carcase is usually accompanied by an increased coarseness in the fibre, and, if this change is brought about too rapidly, also by a tendency to deterioration in the structure of the individual fibres, especially as regards the form and arrangement of the epidermal scales. In the animal economy the greatest variations and changes always occur in those parts which are the least fixed and where vital action is the 1 most active. This is specially the case with the appendages of the skin, which are, indeed, in a sense, almost independent iin their growth of the ordinary control of th 6 remainder of the organism. This is clearly shown in the case which is frequently seen in the human subject where the beard will continue to grow even after death, showing that the individual fibres of the hair, when once the follicle or sac is uniformity in this raw material, between the hair and the root perfected,, are independent organisms, and have a resemblance to' a vegetable rather than an animal character.

It is' on account of this that the utmost care must be bestowed on the housing, feeding, health, and sanitary arrangements of the flock, so as to prevent these variations occurring. So intimate is this connection that the fibres of the fleece become a very fair index of the health of the sheep, and the writer has been able to detect -variations in the development, structure, and lustre of the fibres even from day to day. In the process of manufacture, what the textile producer requires is uniformity in this raw material, becuuse it is impossible for him to set his machinery so that it will accommodate itself to those small variations which occur in each individual fibre, and this is all the more difficult when the variation is not so much in the length of the staple— which can easily be arranged for—as in the diameter, as this results in weak yarn imd irregularity in strength, also in inequality in the* twist in the various parts of the thread, and this is apt to cause faults in many classes of goods. Variations in the health of the sheep particularly affect the cortical portion of tne fibre ond interfere with the spongy nature of this substance, and, when it is remembered that it is upon this attribute that the absorption and fixation of dye-stuff depends, it can easily be seen how serious the matter may become. This deterioration in the substance of the shaft of the hair reacts on the epidermal scales, and causes them to shrink and lose their lustre, and this, in

tha case of the deep grown wools, interferes with one of their most valuable attributes. Nothing, indeed, is more notice)able in case of diseased or degenerated wool than this fall off in lustre. No animal is more easily deranged by neglect than the sheep, and one of the first symptoms when this neglect becomes chronic and they 'are permitted, as it were, to run wild, is the reversion in certain parts of the fleece of the wool to hair, when the softness and curl of the wool diminishes, and the fibres become harsh and horny, often going as far as to produce what are called "kemps," where the normal structure of the ordinary wool fibre is entirely obliterated, and the* whole shaft of the hair becomes horny in texture, and the epidermal scales are obliterated, and thus the fibre becomes brittle and .harsh and loses its felting properties. In this case such fleeces can only be used for the very lowest class of goods, and sometimes ore quite unusable at all. Apart from neglect, some individual J sheep, even in well-tended flocks, are more liable to these variations and reversions than others, and the careful farmer should weed these out, and so raise the standard of quality in the flock. These are only a few of the points which researches into the structure of the wool fibre bring under our notice, but they are all-important matters, both to the fanner and the manufacturer. Fortunately, the . revelation of the defects which may exwt and their causes also reveals, as already shown, the remedy, and in this respect the results of these technical investigations enable us to know the methods we mu3t employ to attain the highest perfection to which we may be able to bring the art of wool production, and give to it its greatest commercial value. A word to the wise is sufficient.