1915] AASE—M EGASPOROPHYLLS OF CONIFERS 285 
bundles soon unite into one, so that four bundles in all with xylem 
facing result; the lower passes undivided to the end of the bract, 
the three remaining spread out and give rise in the scale to a row 
of inverted bundles, seven or more in P. maritima, twelve or more 
in P. Banksiana. No branches are seen to bend toward either of 
the two inverted ovules. Below the middle of the strobilus the 
uppermost one or two bundles, as the case may be, originate near 
_ the lower scale bundles or become united with the latter so that the 
scale supply starts as two bundles. One of the two bundles soon 
divides, so that four bundles including that of the bract result; 
the subsequent course in the appendages is as described before. 
In the lower sporophyll, the scale supply originates as one or two 
bundles very near the bract bundle. In the lowest sporophylls 
the bract and scale supply originates as a single bundle at the base 
of the gap. In either case there is a subsequent separation into 
four bundles which supply their respective appendages as before 
described. In this region of the strobilus the four bundles remain 
closer together in their course through the cortex than is the case 
in the upper. In P. Banksiana the phloem is continuous around 
the four xylem strands, which except for a few parenchyma cells 
would form a solid xylem strand. Near the base of the strobilus, 
in this species, where the sporophyll supply begins as a single 
bundle, the xylem creeps around its protoxylem as a pivot and the 
phloem about the xylem, so that a concentric bundle results. 
On nearing the appendage the bundle drops into four. In this 
species the gaps are small, owing to a shortening of the strobilus axis. 
In both species the sporophyll supply takes a diagonal downward 
course through the cortex in the lower part of the strobilus, in 
contrast to the diagonal upward course taken near the tip. This 
is also likely due to a shortening of the strobilus axis and a conse- 
quent crowding of the appendages. 
For the sake of comparison, the anatomy of a young vegeta- 
tive shoot was investigated. In P. maritima and P. Banksiana 
(figs. 30-35), whether the bud is to give rise to a spur shoot or a 
long branch, a single bundle springs from the base of the cylinder 
gap and supplies the bract, while two other bundles, one at each side 
of the gap, supply the bud. The bud bundles increase in size and 
