3 ?/- 375 <***- ayfler- f-VeZ. 
390 Proceedings of Royal Society of Edinburgh. [sess. 
Plate V. 
Fig. 6. Transverse section through a mane hair of a Somali 
zebra, showing the fairly regular line of demarcation between the 
cortex and medulla, and an equal distribution of pigment through- 
out the cortex. x 300 diam. 
Fig. 7. Transverse section through a mane hair of a BurchelFs 
zebra, showing the irregular line of demarcation between the 
cortex and medulla, and the much thicker distribution of pigment 
towards the interior of the cortex. x 300 diam. 
Plate YI. 
Fig. 8. Section through mane hair of a common zebra, x 300 
diam. (The section from which this is drawn is not quite trans- 
verse, this being indicated by the appearance of the pigment. The 
fact that the long axes of the lines of pigment — which are, as usual, 
arranged longitudinally — do not lie in the same direction as the 
long axis of the section, proves that an absolutely transverse section 
is not circular. This is completely borne out by the appearance of 
other sections through the mane hairs of this zebra.) 
Fig. 9. Transverse section through a mane hair of the pony 
“ Circus Girl,” showing an almost regularly circular line of de- 
marcation between medulla and cortex and finely granular pig- 
ment which is equally distributed throughout the cortical layer, 
x 300 diam. 
Fig. 10. Transverse section through a mane hair from the zebra- 
horse hybrid “ Brenda,” showing general resemblance to fig. 6. 
x 300 diam. 
Figs. 1 and 2 are from The Penycuik Experiments, Ewart. 
Figs. 3, 4 and 5 are from Guide to Zebra Hybrids, etc., Ewart. 
Figs. 6-10 were drawn by Mr Richard Muir from sections 
passing in each case approximately through the middle of the 
hair’s length. The cuticular portion is represented in all the 
figures by the narrow unpigmented layer outside the cortex. 
