66 
RESIDENCE OF THE MISSION AT BUSHIRE, 
gradation from the bird to the quadruped, which Sonnini traced in 
the hopping motion of the jerboa, did not strike me with the same degree 
of conviction. When unpursued the animal certainly hops, though this 
admission does not imply that he cannot walk without hopping. But 
when he is escaping from any alarm, he may almost be said to lay him¬ 
self flat on the surface of the ground from the immense tension of his 
hind legs, and literally to run ventre a terre . Yet as every observer will 
feel that there are shades by which the works of creation gradually 
resolve into each other, and which, by a slow operation, connect the 
zoophyte with the animated world, and the bird with the quadruped, 
the jerboa may still serve as one of the first and most perceptible grada¬ 
tions between two kingdoms of nature; but kangaroos, a larger and 
nobler specimen, would illustrate the connection as correctly. 
On the specific description of the animal I agree with Sonnini’s 
account of the Egyptian jerboas, except that, in two which I examined, 
I could not find the spur or the small rudiment of a fourth toe on the 
heel of the hinder foot; on the existence of which depends essentially 
the resemblance which he has discovered between the jerboa and the 
alagtaga of Tartary. But as the jerboa of IIasselquist, of Bruce, 
and of Sonnini all seem to differ from each other, and from those 
which I examined, in some minute circumstance, it is reasonable to 
conclude, less that there is any incorrectness in the descriptions, than 
that there is an essential variety in the animals. Th e jerboas in the 
deserts before us at Bashire, do not live in troops, as those of Egypt, ac¬ 
cording to Sonnini ; each has his hole to which he retires with the 
utmost precipitation ; nor is it possible to take him by surprise in the 
day, as I learn from Sir Harford Jones, who has had ample oppor¬ 
tunities of examining the history of the jerboas ; and therefore the cir¬ 
cumstance, which Bruce mentions, of his Arabs having knocked 
them down with sticks, extends probably to no general inference. Nor 
can I think that Sonnini is correct in supposing that the animal is 
fond of light. Those which I kept in a cage remained huddled together 
under some cotton during the day, but in the night made such 
