GROWTH-RINGS, N.Z. AND U.S.A. 5] 
In age the New Zealand giant Kauris are probably not the equals of 
the big trees of California. Says ‘‘ Uses of Commercial Woods, U.S.A.,’’ 
p. 59 :— 
In one instance a tree of 24 ft. in diameter was less than 1,300 years old. 
Another of similar size showed more than 4,000 rings, but they were so intricately 
involved that he (the computer) was unable to satisfy himself that he had counted 
all of them. It is believed that no tree of this species showing more rings than 
4,000 has been placed on authentic record. . . . The Forest Service has 
made accurate measurement and record of every ring of growth in a tree more 
than 34 ft. in diameter [including basal bulge and 3 ft. or 4 ft. of bark.—D.E.H.], 
and it is shown that during certain periods of years the tree grew three or four 
times as rapidly as during other periods. It is further shown that the times of 
rapid growth and of slow growth were not dependent upon the size or age of the 
tree, but occurred at different times during the tree’s history, suggesting that 
successive changes in environment produced changes in the rate of growth, and 
accounting for the fact that while one tree 24 ft. in diameter might be 1.300 years 
old, another of similar size might be 4,000. 
Professor Huntington took his record back to 3,400 years.* 
Mr. Cheeseman showed that Kirk’s estimate of the age of Kauri trees 
was excessive, He might have added that Humboldt’s estimate of the 
age of the giant Dragon tree of Orotavo was equally a guess, and is not 
accepted by scientific men in Orotavo, I studied this tree when visiting 
Orotayo a few years ago. 
WorK TO BE DONE ON Kauri Rinos. 
It seems, from p. 144, ‘‘ Forest Flora,’’ that Kirk was not familiar 
with the rings of growth on Kauri tree-sections. _On the large number 
of Kauri rings that I have now seen there is no appearance of secondary 
rings, or indication of Kauri rings being other than yearly. White- 
pine does sometimes show secondary rings, and Honeysuckle (Knightia) 
has no yearly rings, but Kauri rings are generally quite clear, easy to 
count, and certainly yearly. Mr. Cheeseman’s examination of the rings 
on the young trees of known age in the Auckland Domain showed that 
they were yearly 1n every case. 
In New Zealand, with all the solid scientific work that has been done 
in many directions, the rings on these old-time Kauris have not been 
counted and analysed as has been done with trees of similar age in 
America. Kauri rings might throw light on many points of old New 
Zealand history—eyeles of drought or rain, volcanic eruptions, possibly 
the coming of the Maoris or their predecessors with bush-fires. Some 
most interesting results from this work have been published recently in 
America.* The study in Kauri stumps at Kauri Park (p, 12) shows 
various suggestive groups and phases in the growth. | 
It is significant that the giant Californian tree and the giant Kauri 
are found growing in exactly the same latitude on different sides of 
the Equator, which is nearly the calculated maximum of summer inso- 
lation. 
Larcest Existing Kaurt Trees, 
The largest existang Kauri tree is unknown. As long as their destruc- 
tion continues unchecked there is not much interest in trying to find 
out, for what is the largest tree to-day may be gone to-morrow. I 
have heard of several exceptionally large Kauri trees, but further inquiry 
has shown either that the size of the tree had been exaggerated or that 
it had vanished! Mr. Carroll, of Kaipara, told me in 1915 that the 
largest sound Kauri he knew was I1 ft. diameter and 56 ft. bole; the 

* «* Secret of the Big Trees,” by Professor Huntington, of Yale University (Govern- 
ment Printing Office, Washington, Price, 2$d.) 
