1870.] ANATOMY OF THE PRONGBUCK. 341 
cell-structure of the medulla. The cell-walls are serrate ; as is shown ; 
but under a higher power, viz. 250 diameters, the transverse section, 
exhibited in C, brings out still further the markedly denticular cha- 
racter of each medullary cell. The finer hairs to which the term 
wool is applicable are depicted in D. 






Microscopic hair-structure of the Prongbuck. 
A. Portion from the crupper, seen lengthwise. B.A portion, from the occiput. 
C. Transverse section, cell of the medulla. D. Two fibres of the wool. 
The measure of modification contradistinguishing the hair of the 
antilopine, cervine, ovine, and hircine families is as follows. In 
Cuvier’s Gazelle (Gazella cuvierii), which, for our comparison, may be 
taken as a fair type of what zoologists class as an Antelope, each 
hair has a proportionally thick cortex, and the medullary tissue 
is composed of minute, rather irregular-outlined, compressed cells, 
ranged transversely to the long diameter of the hair. 
In the Red Deer (Cervus e/aphus) an equally good example of the 
cervine type,-I find that, relatively to the calibre of the hair, the 
cortical envelope is only moderately thick, whilst the cellular medulla, 
in proportion to that of the Gazelle or Antelopes generally, is con- 
siderably increased. The medullary cells also have large, regular- 
sided, roundish or subhexagonal-contoured walls, not so squeezed 
together as in Gazella and its allies. In the Wapiti and other un- 
doubted Deer an identical pattern prevails, the only obvious change 
being in the size of the cells, which slightly vary in different species. 
In all Sheep, with but slight specific modification, the hair shows 
a vast augmentation as respects medulla to cortex, the latter being 
very thin contrasted with the former. The cells of the medulla are 
much Jarger than in Deer, and preeminently so compared with those 
of Antelopes. Selecting the fleece of the Argali (Ovis ammon), as 
affording a fair example of the hair of the Sheep kind (and it is by 
no means an extreme instance), it demonstrates the said relative 
increment in the size of the cells and corresponding diminution 
of the wall cortex. In this ovine species the medullary cells, 
from a pure hexagonal contour, assume a tendency to an elliptical 
figure. 
Te the Goats a form of hair-structure is met with intermediate 
between that of Antelopes and Deer. Exemplifying the hircine 
