of Edinburgh, Session 1885-86. 
665 
Closely allied to alpaca and mohair in their structure are the 
wools which are derived from all the semi- wild sheep of the 
mountainous regions of Central Asia and the plains of Tartary and 
Siberia, but the fleeces of these sheep are generally more defaced by 
the prevalence of long coarse hairs than is the case with alpaca or 
mohair. In some of these wools, such as grey Yicaneer, dark 
Bagdad, and yellow Pacpathian, we have several distinct classes of 
fibres side by side in the same fleece. The fleeces of these sheep 
indeed exhibit a greater variation in the structure of individual 
fibres than any others which have come under observation. These 
fibres may in the same fleece, and often in the same lock of wool, 
be roughly divided into three different classes — 
(a) Those which have all the characteristics of true hair in 
their most marked degree. 
(b) Those which resemble alpaca and mohair fibres. 
(c) Those which are true wool. 
In the first of these divisions (a) there are several distinct 
variations in the form of the hair structure. We have already seen 
in Plate XXIV. fig. 3, the internal structure of one of these fibres 
taken from a Pacpathian sheep, and its resemblance to a hair. 
The external appearance of many of these fibres is remarkable for 
the very great regularity in the arrangement of the external scales, 
and by their pointed extremities, which gives them almost the 
appearance of the stem of a palm tree. Plate XXIV. fig. 12 gives 
an illustration of one of these fibres, which was taken from a lock of 
Bagdad wool. Occasionally this great regularity in the epidermal 
scales is found in the hairs of more cultivated sheep, as may be 
noticed in Plate XXIV. fig. 13, which is sketched from the surface 
of a coarse hair taken from the fleece of a Cheviot sheep. Some- 
times the construction of the cuticular layer of these coarse hairs 
tends to the production of larger scales than those which are 
usually found on other associated fibres. These scales present an 
appearance as though the larger scales had been formed within the 
follicle by the coalescence of several smaller scales into one, and it 
is specially noticed that in cases where this occurs there is a 
tendency in the free edge or margin of the large scale to follow the 
same contour as the smaller ones. Sometimes there are slight 
