of Edinburgh, Session 1870 - 71 . 
453 
Table C .—Gone of Pin us Lambertiana, in Museum , Edinburgh 
Botanical Garden. 
S 
D 
S 
D 
S 
V 
Top, 
1 
4 
5 
9 
14 
23 = 
Middle, 
— 
2 
4 
10 
14 
24 = 
Bottom, 
1 
4 
5 
9 
14 
23 = 
5 
23 
5 
12 x 2 
5 
23 
Table D represents the four different arrangements in the flower- 
spikes of Banksia occidentals , placed in series so as to show how, 
by slight diminution or augmentation in the number of secondary 
spirals, one arrangement may be conceived to originate from 
another. The directions of the spirals to right or left are stated 
arbitrarily, to suit the purpose of the diagram. 
Table D. 
No. 1, 
D 
S 
D 
S 
7 
D 
7 
^ < 
II 
1 
2x7 
No. 2, 
— 
— 
1 
6 
7 
13 = 
2 
13 
No. 3, 
•— 
1 
2 
5 
7 
12 = 
5 
12 
No. 4, 
1 
2 
3 
5 
8 
II 
CO 
rH 
5 
13 
It is impossible to reflect on such cases as have been adduced 
and not be impressed forcibly with the idea that, as regards their 
production or origination, diverse spiral arrangements are to be re¬ 
garded as allied much more according to the numerical correspond¬ 
ence of their secondary spirals and verticals than in proportion to the 
correspondence of their angular divergences. Such cases, moreover, 
show clearly how a generating spiral may change its direction on 
one and the same axis. 
It is perhaps rash to speculate as to how the different systems of 
spirals in Fir cones originate. On the wdiole, Dr Dickson is inclined 
to assume the bijugate of the ordinary system as the fundamental 
arrangement. He is to some extent confirmed in this view by a 
remarkable abnormality in a cone of P. Pinaster , gathered by 
him at Muirhouse, near Edinburgh. This cone exhibits a left- 
3 p 
VOL. VII. 
