THE GIRTH-INCREASE OF TREES. I9I 
3. Progressive increase and decrease in the growing 
season. 
Abies Lowiana again showed a deviation from the normal 
monthly rise to a maximum, as the percentage was slightly less 
in June than in May; this deviation also revealed itself in Adzes 
Douglasii, Pinus excelsa, and Thuja gigantea, but above all in 
Abies grandis, the healthiest and quickest grower of all my 
Coniferze, where, therefore, disease or weakness cannot be 
suspected as a cause, in which the percentage was 19'°5 in May 
and fell to no more than 7°5 in June, rising again in July to 
20°0. Subsequent weekly measurements of this tree showed that 
there was a complete cessation of increase for at least a fortnight 
in June. 
4. Comparison with the Deciduous Group of the same 
period. 
April. | May. | June. | July. Aug. | Sept. 
Coniferze = - * ‘ é 55 28 26°5 18'5 14°5 7 
Deciduous - < = Fey cee as 12 Bi 80 20°5 5 
The increase is somewhat more evenly distributed in the 
Conifer. It is greater than in the Deciduous Trees both in the 
first and last months, and if we take the first and last bi-monthly 
periods, it is much greater in the first and a little less in the last, 
whereas in the middle bi-monthly period the Deciduous ciass 
has considerably the best of it. The results agree fairly well 
with the comparison already made in the older groups. 
