rrr! 
TRANSACTIONS OF THE SECTIONS. 107 
as to the south of the Kuenluen, in Turkistan. In Western Tibet, particularly in 
Ladak, there are no more yaks in a wild state at present, though [ have no doubt 
that they have formerly existed there. They seem to have been extirpated here, the 
porylation being, though very thin, a little more numerous than in Tibet in general. 
s Ladak has been occasionally more visited by travellers than any other part of 
Tibet, the want of the yak here has probably given rise to the idea that they are no 
more to be found in a wild state at all. Amongst all quadruped animals the yak is 
found at the greatest height: it stands best the cold of the Snowy Mountains, and 
is least affected by the rarefied air. But at the same time the range of temperature 
in which a yak can live is very limited; the real yak can scarcely exist in summer 
in heights of 8000 feet. We often found large herds of wild yaks, from thirty to 
forty, in heights of 18,600 to 18,900 English feet; and on one occasion we traced 
them even as high as 19,300 feet,—a remarkable elevation, as it is very considerably 
above the limits of vegetation, and even more than 1000 feet above the snow-line. 
The hybrid between the yak and the Indian cow is called Chooboo, and it is very 
remarkable that the chooboos are fertile. The chooboos, which are most useful 
domestic animals to the inhabitants of the Himalayas, are brought down to lower 
places, where yaks do not exist, and where consequently they cannot mix either 
with yaks or with the Indian cow. We had occasion to see and examine the offspring 
of chooboos as far as to the seventh generation, and in all these cases we found the 
later generations neither much altered nor deteriorated; and we were moreover in- 
formed that there was never found any limit as to the number of generations. 
The Kiang, or wild horse (Equus hemionus), has been often confounded with the 
Gorkhar, or wild ass, though they differ considerably in appearance, and inhabit 
countries with very dissimilar climates. The kiang exists in the high cold regions 
and mountains of Tibet, the ass in the heated sandy plains of Sindh and Beloo- 
_chistan. The kiang is found in great numbers nearly in the same localities as the 
yak ; he does not, however, go up the mountains so high as the yak, but the range 
of his distribution is greater than that of the yak. The greatest elevation where we 
found kiangs was 18,600 English feet, whilst we traced yaks as high up as 19,300 
feet. The region where the yak and the kiang are found are, in a zoological 
oint of view, among the most remarkable and interesting of our globe. The 
ighest absolute elevation coincides here, it is true, with the greatest height of the 
snow-line, or rather it causes the snow-line to be higher. But those large, high 
plateaus and regions, though free from snow and ice in summer, remain a desert 
throughout the year. The amount of vegetation on them is less than it is in the 
Desert between Suez and Cairo, in Egypt. Nevertheless these high, sterile regions 
are inhabited by numerous herds of large quadrupeds; and besides those already 
mentioned, numerous species of wild sheep, antelopes, and a few canine animals, 
chiefly wolves, as well as hares, are abundant. The herbivorous animals find here 
their food only by travelling daily over yast tracts of land, as there are only a few 
fertile spots, the greater part being completely barren. The great scarcity of vege- 
tation, particularly the entire absence of mosses and lichens, has a very different 
effect, though an indirect one, on the occurrence of birds. Those small plants are the 
chief abode of insects : the want of mosses and lichens, coinciding with a total absence 
of humus, limits, therefore, to its minimum the occurrence of insects, the exclusive 
food of small birds in all extremely elevated parts of the globe, where grains are no 
more found. We indeed met, travelling twenty consecutive days between heights of 
14,000 to 18,200 feet, only with three individuals belonging to a species of Fringilla, 
but occasionally a few large carnivorous birds, as vultures, were met with. 
The Gorkhar, or wild ass (Asinus onager), an animal which, as I mentioned before, 
has been often confounded with the Kiang, or wild horse, inhabits chiefly the rather 
hilly districts of Beloochistan, part of the sandy plains of Sindh ; anda similar animal 
is to be found, if I am not mistaken, to the westward of Beloochistan, in Persia, 
which is called Koolan (Equus hemippus). Dr. Barth lately told me, that, according 
to the description I gave him, he thinks the asses he saw in Africa identical with the 
Gorkhars, or wild asses, of Sindh and Beloochistan. 
I will now try to give an explanation about the fabulous Unicorn,-or animal which 
is said to have one horn only. This animal has been described by Messrs. Huc and 
Gabet, the famous travellers in Eastern Tibet, according to information they received, 
