282 BOTANICAL GAZETTE [OCTOBER 
Investigation 
ABIETINEAE 
The ovulate strobilus in all the Abietineae is composed of a 
comparatively large number of sporophylls.. The sporophyll 
here is obviously composed of two organs. In some forms, as Kete- 
leeria and Pseudotsuga, each of the three-pronged bracts is reflexed 
over the scales below, giving the strobilus a bristly appearance; 
while in others, as Cedrus Libani, the bract is a minute flap, and 
its bundle dies before it reaches the free portion. Between these 
two extremes are many intermediate forms. That the bract is a 
modified leaf seems evident at least in some genera. In Pseudo- 
tsuga and Larix there is a gradual transition from ordinary foliage 
leaves to bracts of a well developed sporophyll; and in abnormal 
cones of Picea, Larix, etc., the bracts are like the vegetative leaves. 
The scale is well developed in all the Abietineae. 
The vascular anatomy of the megasporophyll is less variable 
in the different genera of the Abietineae than is the case in any of 
the other five groups. 
In the lower one-third or more of the strobilus of Pinus maritima 
and P. Banksiana there is a general sterilization, beginning with , 
failure of the ovules to produce seed, followed lower down by the 
abortion of the ovules, and finally at the base of the strobilus the 
reduction in size and final disappearance of bract or scale or both. 
In P. Banksiana the bract disappears before the scale, but both — 
are finally lost, and between the lowest ovuliferous scales and the 
bud scales is a region where the strobilus stalk is smooth except 
for slight elevations (fig. 2). Each of these elevations is supplied 
with a small vascular strand and suggests a vestige of a megasporo- 
phyll. In P. maritima only the scale suffers reduction and loss, 
and the bract, reduced throughout the strobilus, increases in size 
toward the base (fig. 1). 
Correlative with the sterilization and reduction of the append- 
ages in the lower portion of the strobilus are variations in mode of 
origin of their vascular supplies (figs. 3-29). In the upper half 
of the strobilus the bract supply originates as a single bundle at 
the base of the cylinder gap. The scale originates as three or four 
bundles instead of two as in other Abietineae, one at each side of the 
