. The Canadian field-naturalist. May, 1925] The Canadian Field-Naturalist 97. Figure 3.—COMPARISON OF GROWTH FORM BETWEEN CONIFERS OF FIR TYPE AND BROADLEAF TREES (ANGIOSPERMS). Normal growth-form of Grand fir (Abies grandis Lindley) left, and Douglas fir, (Pseudotsuga taxifolia, [Poir.] Britt.) right, viz: single vertical primary axis from which lateral branches radiate in dorsi-ventral symmetry. Normal growth-form of Garry oak, (Quercns Garryana Hooker) centre, viz: initial single vertical primary axis followed by continual bifurcation in which the identity of the initial axis is lost. leade
. The Canadian field-naturalist. May, 1925] The Canadian Field-Naturalist 97. Figure 3.—COMPARISON OF GROWTH FORM BETWEEN CONIFERS OF FIR TYPE AND BROADLEAF TREES (ANGIOSPERMS). Normal growth-form of Grand fir (Abies grandis Lindley) left, and Douglas fir, (Pseudotsuga taxifolia, [Poir.] Britt.) right, viz: single vertical primary axis from which lateral branches radiate in dorsi-ventral symmetry. Normal growth-form of Garry oak, (Quercns Garryana Hooker) centre, viz: initial single vertical primary axis followed by continual bifurcation in which the identity of the initial axis is lost. leader, which soon die off. On loss of the leader a young lateral branch, being pliant, can bend upward so completely that soon the point of bending can not be detected. Older branches, lower down, can not bend and it is therefore only their terminal buds which react to gravity and become vertical. Curious fascia- tion ensues in the girth increment of the older part of these branches. Co-incident with the upturning of the tip of the branch, super-develop- ment of fasciated and looped annual rings appears on the lower side of the older and more horizontal part of the branch and there is of necessity con- tinuity in girth increment between the lower side of the branch and the stem of the primary axis of the fir. In the case of diverted or overturned primary axes similar fasciation in girth increment follows in the stem compelled to grow out of strict vertical direction. Examples of the fasciation of substitute branch- stems and of the diverted primary axes abound in the vicinity of Victoria and every stage and phase of the phenomenon can be readily observed and it would seem that by means of this fasciation stems of conifers of the fir growth form could be made to assume almost any shape desired. I have not found any reference to this fasciation in any text book, though the substitute leaders and overturned axes must have been under obser- vation of foresters, lumbermen and botanist
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