212 
Lang . — Studies in the Morphology and 
* 
Text-fig. 7. Reconstruction 
of the stele of plant E. De- 
scription in text. 
Still further up, the endodermal markings dis- 
appear from the cells lining the inner portion of 
the concavity, and only the slight inward curves 
of endodermis usual in the adult type of leaf-gap 
are found. The endodermal gap then closes, and 
shortly afterwards the xylem ring. Thus the 
plant resembles plant C, except in that the 
internal endodermis becomes complete for a short 
distance in the elongated leaf-gap. 
Plant E is the longest plant that was studied 
in complete series, and a glance at the recon- 
struction of the stele (Text- fig. 7) will show 
that a fairly extended intermediate region is 
formed by the very gradual departure of one 
leaf-trace, while above this came a rapid tran- 
sition to the adult region. Owing to its length, 
this reconstruction has had to be reproduced on 
a somewhat lower scale than the others of the 
series. The base of this plant was imperfect, 
and, although the transition from a stele with 
solid xylem to one with a pith could just be 
followed, it is clear that at least one and probably 
a number of roots are missing from the base. 
The first recognizable leaf-trace dies out as soon 
as it leaves the stele. The next two are larger 
and the leaf-gap in the xylem more extended, 
but in all these three leaf-trace departures the 
endodermis is completed before the departure of 
the trace, and there is no gap in the endodermis. 
Owing to the place of development of the re- 
paratory band of endodermis, there is an appear- 
ance of dipping-in opposite the leaf-gap ; this 
dip is soon lost, the endodermis becoming convex 
outwards, and its explanation does not involve 
the need of ‘ pocketing ’. In the third leaf-trace 
the endodermis is also completed around the 
trace itself. Shortly after the departure of this 
trace and before the gap in the xylem has closed 
the usual root is attached, and a little higher 
up the origin of the fourth leaf-trace, which is 
the interesting feature of this plant, commences. 
The departure of this trace is extremely gradual, 
and as soon as its position is evident in the 
