28 
Lang. — Studies in the Morphology and 
must have taken place, as the embryo not only grew but changed the direction 
of growth of the shoot. This readjustment has led to the similarity in position 
of the organs to the embryo of Botrychium virginianum , though the latter 
is inverted from the commencement of development and has no suspensor. 
The reconstruction not only explained the organization of this embryo, 
but enabled the other series through embryos of corresponding age to be 
interpreted. Thus the two sections figured in outline in Text-fig. 7 are 
from an approximately longitudinal series in a plane at right angles to that 
of the series in Text-fig. 6. The first section includes the stele and the 
trace to the first leaf or cotyledon, the second shows the tip of the cotyledon 
bent over the stem-apex. These sections are figured, because they afford 
a further illustration of the way in which the shoot-apex, including the 
Text-fig. 7. Outline figures of two sections through another mature embryo, f, foot ; cot, first leaf ; 
st, apex of stem. The apex of the shoot is surrounded by a rim of tissue-bearing hairs. 
cotyledon, is sunk in the summit of the embryo. 1 The surrounding rim of 
tissue bears numerous multicellular hairs. 
The section represented in PI. Ill, Photo. 10 was from another series, 
which cut the embryo in an obliquely transverse plane. Its interest lies in 
the fact that it cut the perfectly preserved suspensor longitudinally. A 
photograph on a larger scale of the suspensor is shown in Plate III, Photo. 11. 
The suspensor is seen to consist of the upper tier (s 1 ), composed of a large 
cell, in which, however, a few divisions had taken place, and of the lower 
multicellular tier (s 2 ), which widened gradually towards the embryo proper. 
The two tiers of the suspensor are separated by a thick wall. 
The change from mature embryos, such as those just described, to the 
young plants with an expanded green leaf, such as those figured in my 
earlier paper, is simply due to further growth of the root and shoot. The 
1 Cf. p. 26. 
