412 Transactions. 



atmosphere, and not on ground-water. With reference to this, E. Warming 

 says [" Ecology of Plants, p. 201 : Oxford, 1909), " It is erroneous to 

 suppose that Sphagnum sucks up water from the soil ; it raises water for 

 an inconsiderable distance. The movem_ent of water in a Sphagnum moor 

 is essentially a descending one." 



The conditions of Central Otago at the present are not favourable to 

 the growth of peat, and those bogs which I have examined do not show any 

 distinct signs of renewal after being dug out for fuel, as they should do if 

 the conditions were favourable for its growth. This seems to bear out the 

 statement that the climate is becoming drier. More careful work \\dll, 

 however, have to be done before this can be definitely established. 



Some of the bogs contain abundant remains of the roots and stems of 

 Dacrydium BidioiUii (?). Although no positive evidence could be ob- 

 tained that this shrub or low tree grew on the bogs, it is nevertheless 

 extremely probable that this was the case, since in many parts of the alpine 

 region of the Southern Alps it is a typical bog-plant, although it will grow 

 also in somewhat dry places. The roots are common in the peat which 

 covers the roches moutonnees of the Upper Wairaakariri Valley and other 

 places along the eastern flanks of the range, and it occurs in well-defined 

 layers in the peat-bogs on the line of the Midland Railway near Sloven's 

 Creek, between Broken River and the Cass. These latter may have been 

 swept in by floods when the chmate was more rainy than at present, or 

 they may have grown in position on the bog. The presence of well-defined 

 layers of trees and stumps probably points to recurrent periods when the 

 climatic conditions favoured its growth either on the bog or on neighouring 

 land-surfaces. At the present time in some of the bogs a keen struggle 

 for existence is going on between the Sphagnum and the pine. It is likely 

 that in drier conditions the latter would have the advantage, and temporarily 

 extinguish the bog, as has been assumed to be the case with the pines in 

 the old peat-bogs of Scandinavia and Shetland ; but this conclusion is open 

 to serious criticism. Whatever the causes controlling the relative growth 

 of these two elements, the presence of the layers of wood and peat points 

 to recurrent conditions, or, rather, to probable alternations of moister and 

 drier climate, as a very slight change in one direction or the other may be a 

 determining factor in the struggle for existence between the Dacrydium 

 and the Sphagnum and other peat-forming plants. 



The Presence oe Former Forests. 



Before the arrival of Europeans, and partially contemporaneous with 

 the early settlement, extensive forests containing trees which flourish in 

 moist situations extended over wide areas to the east of the Southern Alps 

 and over Central Otago which are now almost if not entirely treeless. The 

 existence of this forest is undoubted, and its disappearance is usually put 

 down to fires before the arrival of Europeans or in the very early days of 

 the settlement, an explanation which is extremely questionable and not 

 supported by undoubted evidence. The Rev. J. W. Stack, an authority 

 on the Maori history of this part of New Zealand, includes the tradition of 

 the destruction of these forests by fire among those on which little rehance 

 can be placed, though he remarks that there is no impossibility that they 

 were so destroyed. 



The evidence for the existence of this forest is largely based on the 

 observatiojis of the early pioiu'crs and other observers who followed 



