188 Dr Dickson on some of the Stages of Development 
longation of the extremity of the ovule, although very curious, 
cannot I think be of much importance, either morphologically 
or physiologically, since it is comparatively late in its appari- 
tion, and, although of very frequent, is not of universal occur- 
rence, 
Regarding the subsequent stages in the development of the 
pistil, I need not say much. The ovule always remains ex- 
posed by the anterior and posterior notches between the apices 
of the carpels, but always to a relatively less extent as de- 
velopment advances. The apices of the carpels never pro- 
ject as style-like prolongations, but are closely applied to the 
sides of the ovule. (See figs. 12 and 13.) 
In the flower represented in fig. 10, the unsymmetrical 
development of the wing-like margins of the pistil has com- 
menced, 
The great wing is developed sometimes on the right, some- 
times on the left side of the pistil; but the side upon which it 
occurs is constant in any given cone. This, I find, is de- 
pendent upon, or at least correlated with, the direction of the 
generating spiral of the cone. If the cone-spiral be from 
right to left (supposing the observer to be in the axis of the 
spiral), the wing is developed on the right side of the pistil ; 
but if, on the contrary, the cone-spiral be from left to right, 
the wing is developed on the left side of the pistil.* The 
relation of the unequal development to the disposition of the 
scales may be briefly described as follows:—If we take a bract- 
scale—say No. 1 of the cone- 
spiral—we find that of the two 
bract-scales immediately applied 
to its upper or inner surface, 
No. 6 extends from one side to { 
past its middle line, and entirely ( 
—— 
-- 
an 
- 
covers the flower of bract No.1; “<--~ mere ws 
while bract No. 4 extends from Lae 
the opposite side just to the margin of No. 6, without overlap- 
ping it. It would appear almost as if the development of the 
* J have examined six cones with reference to this point—three with right- 
handed, and three with left-handed spiral—and all with the result stated 
above. 
Ee a ———— 
