THE LAKES 13 



one another, have presumably been lodged by water action of some sort. 

 In the site of this trough or long hollow a great river might have been 

 imagined to have run at some period, a river which might have left the 

 " Big swamp " once a sheet of water and the present lakes Tutira, 

 Waikopiro, Orakai, Opouahi, and Temaru, further to the north Waika- 

 remoana and Waikareiti, further to the south Waipukurau, Te Koto-a- 

 Tara and Wairarapa, as evidences of its former course. It might 

 have been imagined, in fact, that this chain of lakes had been scooped 

 out by some vast old-world river. 



There are, however, difficulties in the acceptance of this theory. 

 The sands and conglomerates are not mixed, they are sharply distinct ; 

 certainly the latter do not contain that proportion of sand which might 

 be expected in a river-bed. The shape, moreover, of the pebbles suggests 

 neither the grinding of a shelving beach nor the erosion of a running 

 river. In each conglomerate band lie horizontal seams varying in size 

 of stone. Inspection of these seams suggests that their pebbles have 

 been sown in a vast top-dressing, rocked into settlement rather than 

 rushed into position by chance of currents. Perhaps these stones, 

 originally cubes frost-fractured, have been ground by a more remarkable 

 trituration; perhaps their smooth, ovoid form has been acquired by 

 volcanic boilings or tossings. At any rate they are perfectly different 

 from stones of the same material gathered from the top of the Newton 

 range stones evidently shaped by some little stream that ages ago 

 must have flowed there. 



Alternate layers of sand and conglomerate seem in fact to have 

 been laid down very much as on eastern Tutira sands, limestones, and 

 marls have been superposed one on another. Perhaps, indeed, a more 

 profound likeness may be traced the depths of strata conforming or 

 corresponding to one another on east and west. 



There is another difficulty also in regard to the fashioning of the 

 Tutira lake basins by river action : the existence of the coupling spurs 

 already mentioned, spurs here and there linking one range to another. 

 Two of them traverse the breadth of the lakes, one of them at either end 

 of Tutira lake proper, a third barring the way at a slightly higher eleva- 

 tion south of Waikopiro. These coupling spurs, as elsewhere on the run, 

 cannot be reckoned as enormous afterthoughts, as avalanches of rock and 

 soil solidified. They are marl basic, homogeneous parts of the original 

 scheme of things. Their presence at right angles to the length of the 



