Kirk. — Growth-periods of New Zealand Trees. 



431 



head of Diamond Lake, are closely-crowded young trees, often with only 

 a few square inches of soil-surface for each tree. In many cases they are 

 drawn up to a height of from 20 ft. to 30 ft. Table B, III, shows the 

 radial increase for six of these plants. For the first of the ten-year periods 

 these made nearly three times the radial growth made by the forest saplings, 

 and a greater growth than that made by the four big trees in their first ten 

 years. Those that had completed a second period showed greater growth 

 than the forest saplings in the corresponding period, but less than the big 

 trees had made. On the whole, they tend to show that competition with 

 trees of their own age has been less retarding of diameter-increase than 

 competition with older trees would have been. 



No record was made in the case of any tree of which the foliage was 

 not available to make certain identification possible. 



So far as I could learn, the road was made about twenty -two years ago. 

 As beech-seedlings lose little time in starting, it is probable that some 

 of those that I examined were among the first competitors on the newly 

 cleared site. If so, there is no reason to suppose that two growth -rings 

 have been formed in any one year. 



The data here given are recognized as inadequate for the foundation of 

 a theory, but are, I think, adequate to show that in measurements of our 

 tress we should have regard to growth-periods, and should not be content 

 with a statement that a tree of a given age has a stated diameter. 



Table A. 

 Nothofagus fusca, Paradise, 17th February, 1920. 



Totara (Podocarpits totara) in Biology Museum of Victoria University 



College. 



