18 HORN EXPEDITION — NAHRATIVE. 



A few montlis later as T passed throutrh the same district, soon after a heavy 

 fall of rain, the whole scene was changed. Everything was green and hright and 

 teeming with lif(\ All the trees and shriihs iiad })ut on a fri'sh growth of l('a\es, 

 the ground was covered witli a rich crop of grass amnngst which were acres of 

 clumps of white llowt'ring Amaryllids (^Crimiiii Jlaccidimi)^ tlu^ cieeks and clay-pans 

 were filleil with water, birds of various kinds — wood duck, teal, water hens, 

 plovers, and many others were to he counted hy the scor(>. These l)iids appear 

 with the rain, and then as the water-holes dry up disappear as cpiickly and 

 mysteriously as they have come. 



The clay-pans were now filled with a distinct and abundant fauna of thiMr 

 own. Day and night they were alive with the croaking of frogs ; Esthei-ias ;ind 

 water beetles were darting up and down ; hundreds of Apus were swimming .ibout 

 or else scooping out the sand on the margins of the watei'-holes and so making 

 little holes in which they simply lie and die as the water I'apidly dries up. 



The whole change from sterility to exuberant life had taken place as if by 

 magic within the space of only a few days. 



It is woith while noticing in more detail the water hole and clay-pan fauna of 

 the Central area, for probal)ly it is very similar in its nature o\er the whole of the 

 interior, and it consists of representatives of thi'ee groups of animals which ha\e, 

 each in its own way, become especially adapted to the climate of the steppes and 

 desert with their long seasons of drought and short intervals of rain. 



These three groups are the Amphibia, Arthropoda, and Mollusca*. 



To begin with the Amphibia. Standing by a water-hole or clay-pan though 

 you can hear the frogs croaking all around you cannot so easily see them. The 

 surface of the water is flecked with the long stalked floating leaves of the Nai-doo 

 plant {Afarsi/en //iiadrifolia) which are fully grown, while the permanent short 

 stalked leaves around the base are as yet only beginning to develope and are 

 covered with water. 



If you disturb the water you will see a number of little green patches, which 

 you have probably taken for Nardoo leaves, suddenly disappear. These are the 

 heads of one or two kinds of frogs (either Chiro/eptes platycepliahis or Hckioporns 



" This refers to the water-holes and clay-pans in the desert and stony talile-larid country which arc of 

 temporary nature and not to the fewer deeper and more permanent rock-i>ools amon5;.st the Ranj^es. I ha\e 

 puri)0sely omitted Fish liecausc they do not form part of the iiermanent fauna of these water-holes and clay -pans, 

 bciiii; only washed down into them dnrin'^- flood times from the permanent pools amon','st the Uanues, or ])erhaps 

 carried aliout in the form of i<i,'i;s attached to tlie feet and fcatlicrs of birds. 



