16 Transactions. 



Fig. 76. Longitudinal section, apex 0. Cunninghamii (seven leaves). 



r., ramenta. 

 Fig. 77. Young plant, D. squarrosa. 

 Fig. 78. Young plant, C. dealbata. 



Plate V. 



Figs. 79-81. Pi-otostele of C. dealbata, giving off petiole bundle (x v x x ). 

 A parenchyma cell (p.) first appears in the xylem. x 330. 



Figs. 82-84. C. Cunninghamii. Protostele to siphonostele. x 330. I, the 

 first leaf, has been given off here. In fig. 84 note the 

 distinction between the parenchyma of seconddeaf bay 

 and that of stem (bilow third leaf). 



Figs. 85-88. Dicksonia squarrosa. Similar transition. Sections between 

 the first leaf and the foot (the plant had four leaves) 

 X 330, In fig. 86, p., parenchyma cells appearing ; in 

 fig. 87, parenchyma increased — px., protoxylem from the 

 leaf ; fig. 88, above insertion of leaf. 



Art. II. — Some Aspects of the Terrace-development in the Valleys 



of the Canterbury Rivers. 



By R. Speight, M.A., B.Sc 



[Read before the Philosophical Institute of Canterbury, \st Mm/. 1H07.J 



Plates VI-VIIa. 



Part I. 



Explanatory. 



The substance of this paper formed part of an ex-presidentml 

 address delivered before the Philosophical Institute of Canter- 

 bury. Considerable alterations and additions have been made 

 -to it, but the main conclusions stated originally have been 

 retained, and further evidence put forward in support of them. 

 The paper attempts to give, first of all, some account of the mode 

 •of formation of the terraces in the main river- valleys, and then 

 considers the evidence of elevation and depression of the land 

 during late geological times. Without attempting to summarise 

 and criticize all that has been written on the subject, the author 

 gives some account of this, especially in its bearing on terrace- 

 formation, and finally he draws attention to the importance of 

 frost erosion in the Canterbury mountains, and suggests that 

 the supply of waste is a powerful factor affecting the erosive 

 power of the rivers, and therefore, directly or indirectly, the 

 ■conditions favourable to terrace-development. 



