326 A STUDY OF FARM ANIMALS 



Soundness of fiber means that it will 'stand a very good 

 tension without showing a weakness at any one place. Such 

 a fiber must come from a healthy animal. 



Unsoundness of fiber is manifested in two ways. In some 

 cases of sickness or unfavorable conditions of feed or water, 

 the fiber becomes "tender," and easily breaks when subjected 

 to tension. Another form of unsoundness may occur from 

 sickness, starvation, or change of feed, in the fiber'? contract- 

 ing, forming what has been termed a "break." This is easily 

 seen by the eye, and it is not uncommon to find cases where 

 a break shows clearly at one point through the fleece. Such 

 a fiber is very defective, and easily breaks on tension. 



A cotted fleece results when the wool on the sheep gets 

 entangled in its own scales, and thus goes through a natural 

 felting. This condition especially occurs when sheep are 

 not in good health, and are packed close together in pens, 

 so that the wool is placed under pressure. Cotting occurs 

 more commonly with long-wool sheep than other breeds. 



Kemp is a hard hair, found mostly on the head and 

 thighs, that will not take a dye. It is commonly white, 

 although there is dark colored kemp. A fleece that has 

 much kemp is very inferior. 



The yolk, or grease, of wool is the oil from the sebaceous 

 glands which naturally works up the fiber toward the tip, 

 where it takes on dust, so that the exterior of the entire 

 fleece appears more or less dark and greasy, according to 

 the kind of sheep. This yolk washes out to some extent in 

 clear water, but in the woolen mills it is removed by a process 

 of "scouring," that is, being washed in water containing 

 alkali, which removes all the external grease. "The differ- 

 ence in loss of yolk," says Professor Hawkesworth,* "is great 

 when you deal with an average clip of Merino, and one of 

 an extra fatty nature. The former will lose about 20 to 25 

 per cent, and the latter .45 to 60 per cent (exclusive of dirt) 

 when both are thoroughly cleaned." American Merino wool 



*Australian Sheep and Wool, Alfred Hawkworth, 1906. 



