NORTH AUSTRALIAN MAMMALIA. 215 



themselves in shallow depressions scratched in the soil, sandy 

 patches being preferred. Towards sundown, when the heat of 

 the day is somewhat modified, they commence running about to 

 feed. Every night the Jungle Kangaroo goes to the river to drink ; 

 but the time for its visit to water may vary, and is in a remarkable 

 way influenced by the moon at different stages. 



When the full moon rises just after sundown, and practically 

 all night throws its bright vertical light over the landscape, 

 the animals at any time, when thirst compels them, make 

 for water. By crescent and decrescent moon, on the contrary, 

 when only the first and last hours of the night are dimly illumi- 

 nated, sundown is for all Kangaroos the signal to seek water. 

 They must have light; in darkness no Kangaroo dares to 

 approach the river, and that with good reason ; because at the 

 drinking-place the hereditary foe of the species, the great Croco- 

 dilus porosus, is lying in wait, and, notwithstanding all precautions, 

 its strong jaws close on many a young and inexperienced indi- 

 vidual. Many are the victims which during lapse of time in this 

 way have succumbed, and the species has in consequence, in 

 especially exposed places, learnt to take its precautions to antici- 

 pate the cunning devices of the Crocodile. 



Where long flat sand-banks stretch out into the river, Macro- 

 pus agilis chooses its drinking place. Here the animals have 

 a free view, and, what is more important, they do not need to 

 drink at the very shore. For a distance of several yards from 

 the water's edge they dig a hole in the water-soaked sand, 

 patiently wait until this is filled, and thus safely quench their 

 thirst. In places where no Crocodiles are found this course of 

 proceeding becomes unnecessary, and is consequently not em- 

 ployed. These facts may be considered as illustrating to what 

 a considerable degree difficult and strongly exposed conditions of 

 life are capable of improving the intelligence of a species. 



All night the Kangaroos are feeding in the open forest or in 

 the plains, and shortly after sunrise they return to the jungles. 

 Besides the Crocodile, the Jungle Kangaroo has only one enemy 

 of importance — the aborigine ; but, thanks to its cunning and 

 the imperfect hunting methods of the native, the species is nearly 

 everywhere exceedingly plentiful. 



Sometimes this species is also found very numerous in dry 



