THE FUTURE OF NATIVE AVIFAUNA 215 



There are other breeds certain to have disappeared from the station 

 but for its innumerable gorges ; in them all pastoral changes cease, sheep 

 cannot tread their banks nor cattle follow up their narrow beds. These 

 scores of miles of gorge-bottom will never be trodden by man ; they are 

 unaffected by the alterations of plain and hill above, they are only to be 

 reached by rope-work. Into a few I have myself from time to time 

 attempted invasion, wading the shallows, climbing the barriers of piled 

 flood debris, working hand over hand along the cliff scrub, swimming the 

 cold, clear, unsunned pools, but always after a few hundred yards finding 

 myself blocked by smooth-sided inaccessible cliffs and waterfalls. On 

 the beds of these canyons there are shreds and patches of habitable 



Tut nestlings hand-reared. 



slope, deposits of deep soft flood soil rich with flakings of marl, vermic- 

 ulations of sandstone, and leaf-mould from the fern-feathered preci- 

 pices. Into these rifts during the course of ages the Kiwi (Apteryx 

 mantelli) and Weka (Ocydromus earli) have sunk with the sinking of 

 the streams themselves. ./Eons ago they were surface birds ; now, per- 

 haps, in the deepest ravines they may have almost differentiated as island 

 races do from their fellows of the plains and hills above. At any rate, 



