324 BOTANICAL GAZETTE [ NOVEMBER 
of irregular three to four sided prisms, whose sides are more or 
less arched. In cross sections the cells appear to be pressed 
together in the direction of the long axis of the stem, their 
lumina being longest in the radial direction. The cells are 
about equally thickened except where the pits appear to meet, 
being separated only by the primary cell wall. : 
As has already been stated, the leaves of Picea have promi- 
nent pulviniat their bases. Masters* calls attention to the fact 
that the central fibrovascular bundle of the leaf passes directly 
from the axis into the leaf, and does not traverse the prominent 
swelling at the apparent decurrent base of the leaf. The pul- 
vini, therefore, do not form a part of the leaf, being mere out- 
growths from the sub-epidermal and corky layers. In buds of 
Picea, especially in the terminal buds, ” these swellings or pulvini 
are collected into a mass surrounding the bud. On this account 
the bud appears swollen beneath the bud scales, which, like the 
leaves, have these swellings and thus aid in making the basal 
portion of the bud assume this fleshy character. 
The same is true in species of Abies, except that the appar- 
ent decurrent basal swellings of the leaves are much less marked. 
The terminal shoots and buds of A. dalsamea show toa great 
extent the same characters as those of Picea, the buds having 
he characteristic swelling below the bud scales. The bud scales 
are also provided with thickened bases, which in their compact 
arrangement in the bud have lost their decurrent aspect. The 
basal swellings of the innermost (uppermost) bud scales, covering 
the sides and apex of the growing points, differ essentially in — 
structure from the lower and outer scales in that they consist of 
a mass of thick walled cells, very similar in structure to the cells > 
of the pith septum, above which they project (fig. 10, ¢ = 
cross sections made at the base of the septum, a ring of this col- | 
lenchymatic tissue can be seen in the section (fig. 10, 4) - Busse 
_ 8 Masrers, M. T.: Note on the relation between morphology and physiology "= 
the leaves of certain conifers. Jour. Linn. Soc. Bot. 27: 547- 1879- Uae ee 
Compare Tubeuf, zézd.,p. 19. — 
* Busse, W.: Beitrage zur Kenntniss der Morphologie und Jahresperiode 4°* 
Weisstanne. Flora 77: 121. . gt ee 
