666 
Proceedings of the Royal Society 
surface markings or depressions on the larger scales, which, seem to 
indicate the margins of the smaller ones out of which they were 
formed.’ The union is, however, so complete that it is impossible, 
except in a very few instances, to separate the larger into the 
smaller scales, even by the use of reagents. Plate XXIY. fig. 14 is 
sketched from a coarse hair of Pacpathian wool, in which the 
surface markings of many of the large scales show the configuration 
of the smaller scales out of which they were formed. 
Occasionally the whole epidermal tissue of these coarse hairs 
assumes an entirely different appearance, in which the usual scaly 
structure is replaced by a series of interrupted longitudinal channels, 
which give the fibre the appearance of a vegetable rather than an 
animal structure. One of these fibres, taken from a lock of Jora 
wool, is given in Plate XXIY. fig. 15, in which the cuticular envelope 
resembles a fluted column, and where any transverse lines are present 
to mark the free margins of the scales, they not inaptly supply the 
semblance of joints in the masonry. In all cases where this peculiar 
structure is visible in the cuticular layer, there is associated along, 
with it an equally distinctive cortical and medullary formation.. 
The cortex exhibits a coarse texture of spindle-shaped cells with 
longitudinal striae, while the medulla is composed of large and 
distinct rounded cells with well-marked nuclei. The whole arrange- 
ment is indicative of a loose formation, with considerable air spaces 
existing both in the medulla and cortex. Plate XXIY. fig. 1 6 repre- 
sents the internal structure of the fibre, whose external surface is 
given in fig. 15. Probably this extreme variation from the normal 
type may have arisen from the shrinking up of the loosely-packed 
cells in the cortical part, which by their attachment to the epidermal 
layer, which seems to be thinner than is usual in hairs of this 
diameter, have drawn them inwards, and thus formed corrugations 
at the intervals between successive bundles of the elongated cells. 
The second class of fibres ( b ) have a very close resemblance to- 
those of alpaca and mohair, but they are usually softer and more 
pliant, with less lustre and a greater tendency to variation in the 
formation of individual scales in the cuticular layer. One of these 
fibres, taken from a lock of Pacpathian wool, is given in Plate XXIY. 
fig. 1 7, and cannot be distinguished from a fibre of alpaca, such as that 
given in Plate XXIY. fig. 9, except by its association with other fibres 
