100 
REPORT—1854. 
tion give a series of rhomboidal figures on the surface of the cone; ami on measuring 
the angles of these figures they were found to be (approximately) 120° above an<l 
below, and 60° at the sides. The scars of the fallen leaves also form two set* of 
spirals on the branch, and these by their intersection also produce regular rhomboid*. 
Each of the sets of spirals on the cone and branch is composed of several spirals 
which may be called threads. The number of threads on any given set of spiral* is 
always one or other of the following (the usual numbers in Phyllotaxis), 1. 2, 3,5. 
8 , 13, 21, 34, &c., in which scale every succeeding number is made up by thr 
addition of the two preceding ; this holds true of all the Comferte. The, number* of 
threads of the two opposite sets of Bpirals are always contiguous ones in the abovr 
scale ; thus if the number of the one be 5, that of the other must be 3 or 8. Thr 
number of threads in the spirals seems definite for every species. There seems a, *° 
to be a regularity in the number of turns round the axis taken by the spiml* m 
ascending from the base to the apex of the cone. He (Dr. M'Coab) had observes 
that the expanded cones are often types of tire particular specie* of tree on which 
they grow, and he illustrated this by examples. 
Some further Observations on the Correspondence between the Lcaf- Vfnnhon 
and Ramification of the. Plant. Tin the Rev. Professor J. M’Cosib TL. • 
Belfast. 
The author set out with referring to previous observationsof liis.of which an ahstrad 
will be found hi the Sectional Reports for 1852. The correspondence may 
illustrated under two general heads 1st. Between the disposition of the bran 
on their axis, and that of the veins on the midrib, or other veins from which > 
spring. In trees where the loaf has no leaf-stalk, the tree is feathered from 
ground ; and, on the other hand, when the leaf has a leaf-stalk, the tree hasi a i 
unbranched trunk. It had been objected that the beech leaf has no • ea, ‘rf .. 
whereas the tree has often an unbranched axis. This objection he had been I 
answer to the satisfaction of the gentleman who urged it. It is cuatomoij in I 
ing out beeches to strip off the lower branches, and cut over the axis, and hence 
form which the plant often assumes in lawns; but the beech, when unjun ^ 
cattle and not drawn up bv being planted in the heart of a wood, is [ ea || f 
branched from the base. This may be seen from its mode of growth in h g : . 
would have it to be understood, however, that this correspondence does no' j n 
!? at , . . e . trc . c aml lcfl f necessarily assume precisely the same shape. •’ an ,| 
e leaf ia pinnate, there is no correspondence between the form of the ■ |n 
he form of the tree. He was inclined to think that wlu-n the lent n P>"" ■}*' ^ 
the ash and monntumash, the tree is decomposite; that is, instead “[""jLjrb, 
on? mam axis from top to bottom, it sends off in a scattered way branch after 
nl thn " 18 ° 8t - 2nd - The branch goes off from its axis at much the 
ntahn i Cin f.°. e8 . 0ir from the midrib or lateral vein. There was little b»vc 
establishing this m plants with woody structure, or in herbaceous pl*» ts ' | ,2 
L!^i i i nC V ar ", not a ,,u re flower-stalk. The only exceptions wbicft 
1 in plants with true branches were those with decurrent leaves, such ^ 
I e “ c ™*? rn an tl« seems to be affected bv the decurrency of the J* ‘^cfc 
&r ad,ffi « n «*tBbli«hing the correspondence in herbaceous P 1 ® 0 *** t ,r 
mther have no branch, or in which it is difficult to say whether wc have a“ yr *,ii 
rw& korl ? f - !te,k * tlie more so as botanists had not 
m iml'li to distinguish between branch and peduncle. He had found I rt> 
be nl lr ieS V'r V8 f ° herbaceous plants, to distinguish between ' vbat ' ific .v 
tion 1,n . mar >’ and 8ec o n dary angle, both of venation and 
lateral veins ^ primary angle, that made by the main branches i fSS erv*i°* 
ZilS *“p •'ennd.ry, that ma* bv the tester branches ■ **** 
1»* *™>* in many cases, that 
ancle of this leaf 5f' s,a k g°es off corresponds, not to the primary. . ms** 
Sfi *» W ™ * ** °r » •»— ° f 
