184 CHRISTISON—OBSERVATIONS ON 
TREES IN WHICH THE GIRTH-INCREASE INCREASED IN THE SECOND PERIOD. 
Ny 
x Average Annual Increase. Girth. 
| Species, 
= 1887-91. 1891-96, 1896. 
vi Abies grandis - = => - 1-49 2°13 20°55 
2 Pinus excelsas- - - - 1:08 eit 1490 
65 Araucaria imbricata - -~ - ‘61 64 21°30 
3°18 3°88 
In this Table only Adzes grandis shows a very marked increase 
in the second period, up to a girth of 20 inches, while in Pzmus 
excelsaand Araucarta tmbricaia the difference is little ee 
at girths of 15 and 21 inches. 
In the aggregates the loss in average annual increase in seven 
species was 1°16 in., and the gain in three was ‘70; the nett loss 
being thus “46. 
6. RANGE OF THE AGGREGATE ANNUAL GIRTH-INCREASE. 
The range of the 19 Coniferze of 9 species under observation 
in the first decade, 1878-87, was very great, as shown below, 
being from 9°60 to 16°60 inches in the whole, and from 5’03 to 
8:27 taking species averages. As fully detailed in former Papers, 
the maximum, 8°27, was in 1878, and was followed bya decline 
in the three eminently unfavourable succeeding years to 6°16, 
but the minimum, 5°03, was not reached, after a rally in 1882, till 
1883, and after a second rally for two years a third fall took 
place in 1887 nearly to the minimum. 
1880. | 1881. | 1882, | 1883. | 1884, | 1885. | 1886, | 1887. | 
1878. | 1879. 
6°68 | 5°80 | 
| 827 | os | 7°05 | 6:16 (705 03 6-41 (698 
In this decade-list we can see distinct evidence of a prolonged 
depression after the three bad seasons. The standard of 1878 
was never again nearly reached, and after some fluctuations the 
final year was not far off the minimum. — A detailed inqury shows 
that five species, Pinus excelsa, Alies Douglastt, A. Lowiana, 
Pinus sylvestris, and Araucaria tmbricata had their girth-increase 
