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TYPES OF DOMESTIC SHEEP AND WILD LIFE [ Vol. XXII, Part IV
2. There is a wide range in the number of scales per 1-in. length of the fiber—
the number may vary from 1,000 to 7,000. Irrespective of fiber diameter, the
number is smaller in wool fibers (average 2,108) than in hair (average 3,635) and
kemp (average 5,383). However, the number of scales per 1-in. length and 100µ
width of the fibers is larger in the wool fibers (average 11,696) than in hair (average
6,001) and kemp (average 3,664). Thus, strictly speaking, the number of scales
in wool fibers is larger than in hair and kemp. No relationship seems to exist
between the number of scales per unit length and the wool type.
3. The average scale height in all types of wools ranged between 9.7µ and
39.5µ (average for wool, 14.85µ ; hair, 22.8µ ; and kemp, 18.9µ). Contrary to
the observations of Skinkle [20] that the average scale height of wool does not
exceed 18.0µ, some wool types showed maximum scale heights higher than this
limit. Although, on the average, the limit was never exceeded in the fine, cross-
bred, or medium-wool types, when taken collectively, the average scale height was
higher than the limit in the case of long wools (average 24.1µ). In the case of hair
fibers and kemp, the scale height exceeded 18.0µ in many cases. It is therefore
doubtful that this criterion for distinguishing between wool and mohair can be
relied upon.
4. The number of scales along the margin of the fiber per 100µ, length varied
from 3 to 11 for all wool and fiber types. The average number of scales on the wool
fibers was 7.2 ; on the hair fibers, 5.3 ; and on the kemp fibers, 6.8.
5. The scale index [8] was calculated for all wools and fiber types. The range
was from 1.143 (maximum for mixed wools) to 0.064 (minimum for kemp). The
average scale index for all wool fibers was 0.814 ; for hair, 0.396 ; and for kemp,
0.110. There is a distinct difference in scale index between the different kinds of
fibers ; the scale index for the wool fibers ranged from 0.517 to 1.143 ; for the hair
fibers, from 0.170 to 0.538 ; and for the kemp fibers, from 0.64 to 0.207. The
ranges, as well as the averages, show that the scale index increases progressively in
kemp, hair, and wool fibers. Thus, the scale indices differentiate between kemp,
hair, and wool fibers but are not accurate for heterotypical fibers. Hausman [8]
observed a similar relationship between scale index and diameter of fiber for fur
fibers. With an increase in fiber diameter, irrespective of type, there is a cor-
responding decrease in scale index. The relationship is clearly shown in the Ap-
pendix Tables I-III, which include all of the wool and fiber types.
6. There seems to be no relationship of any of the attributes—number of scales
per unit length of the fiber, average visible scale height, number of scales per 100µ
length along the margin, scale index —to breed or wool type. The observation of
Mirzoeva [17] that the number of scales for a given length of wool (265µ) and the
form and area (in µ 2 ) in the purebred Merino, Turkmenian fat-rumped, lomud,
and Erek sheep are specific to the individual breeds may be true because of the wide
range of variation in the types. However, this generalization is not accurate
when the types are more closely related.
7. From the different attributes studied for the scale structure, it appears
that the undercoat of the wild species studied was very similar to the undercoat
of mixed-wool sheep or the wool fibers of fine-wool breeds, and the outer coat is
akin to thin kemp fibers of domestic sheep. The number of scales per 1-in. length