418 



as a collecting ground, it nevertheless yields some interesting 

 types, and it is more than probable that, given time, a 

 systematic investigation would reveal a peculiar fauna and 

 flora suited to the remarkable conditions presented. Some 

 tendency in this direction was noticed during our hurried 

 transit, especially in the nature of assimilative colouration. 

 A remarkable locust (Brachyttttix) was found only on 

 the gibber, and its reddish-brown colour exactly matches the 

 stones among which it lives; this, coupled with its sluggish 

 habit, renders it most inconspicuous. Mention may also be 

 made of another locust (Eremobia) which, together with other 

 insects, are coloured in harmony with their surroundings. 

 Among the reptiles the Agamoid lizard, Tyjmnocryptis 

 lineatus, provides an excellent example. It was not until 

 the lizard moved that it could be detected, and if its exact 

 settling place was not noted, it could not be found until it 

 again ran. The colour of the Desert Chat, Ashbyia lovemis, 

 which bird is also confined to the gibber country, suggests 

 that it owes its brown back and yellow belly to an association 

 with its surroundings, for it is certainly an inconspicuous 

 little bird in its native haunts, and can with difficulty be 

 detected ; even its bright yellow belly answers to the sand 

 patches found between the reddish-brown stones. 



Rotten Ground and Claypans. 



The term "rotten ground" is applied to those extensive 

 areas which in flood time are under water, and is a useful 

 expression indicating dry land subject to inundation and 

 having its character considerably changed in consequence. 

 This land is of spongy and porous nature, but to what 

 circumstances such may be due I am not aware. Certain it 

 is that the dry land supports a luxuriant growth of a 

 wretched burr, and it may be that when covered with silt 

 forms a kind of peat, which would accord with the conditions 

 observed. Even when dry the camels sink deeply, but when 

 soaked with flood water or heavy rains the land must be a 

 veritable bog, as the foot-holes made during such periods 

 by mobs of cattle, and remaining until the bog dries, 

 amply testify. Such impressions are spoken of as "crab 

 holes," and were a source of considerable danger to the 

 camels. 



Claypans, on the contrary, though extremely boggy in 

 wet weather, dry with such a hard surface that foot of man 

 or hoof of horse leave little or no impression. Some of the 

 claypans are composed of a certain addition of earthy matter, 

 and such when dry crack all over. These pans are charged 



