386 Proceedings of Royal Society of Edinburgh. [sess. 
Zebra-Horse Hybrids .* 
The hairs of several of Professor Ewart’s zebra-horse hybrids 
have been examined and sections cut. Seeing that the dams of 
these animals belong to different breeds, it might at first be expected 
that we should find quite as much diversity in the character of the 
hybrid hairs as in those of the dams. Such, however, is not the 
case, for the hairs of the hybrids are for the most part constant in 
shape and in the relative development of the medulla and cortex. 
The measurements, taken as before, of the shoulder hairs of the 
hybrid “ JSTorette,” whose dam was a Shetland pony, are not widely 
different from those of the sire, the Burchell’s zebra : — 
Breadth of cortex on one side Breadth of hair in 
of medulla in three places. three places. 
They point to the conclusion that in the transmission of the 
character of the hair the Burchell’s zebra is prepotent over the 
horse. 
In some cases, however, the hybrid hairs do not resemble those 
of the sire any more than those of the dam, but this is not because 
they depart from the hybrid type, but because the hairs of the 
dam happen to be not dissimilar to zebra hairs. It has been 
mentioned that horse hairs, owing to the large number of breeds of 
horses, are very variable, and so it is not to be wondered at that 
in some cases sections through horse hairs should resemble sections 
through zebra hairs. This is the case with sections taken through 
the hairs of the mane of Professor Ewart’s Clydesdale mare, “ Lady 
Douglas,” the mane hairs of whose hybrid offspring “ Brenda ” are 
if anything more like those of the dam than those of the sire, 
“ Matopo.” A more typical case is that of the hybrid “ Sir John ” 
(Plate IV.). Here the dam was a skewbald Iceland pony, 
“ Tundra,” and the sire the Burchell’s zebra. Sections through 
the mane hairs of “Tundra” are identical in appearance with 
sections through hairs of “Circus Girl,” which are figured. 
* Vide Ewart, The Penycuik Experiments , London, 1899 ; and Guide to 
Zebra-Hybrids, Edinburgh, 1900. 
(1) '0144 mm. 
(2) -0162 mm. 
(3) *0198 mm. 
‘081 mm. 
•126 mm. 
‘054 mm. 
