Seed in the Scitamineae . 
7 
sarily a sinuous one. Yet this appears to be no practical 
difficulty in the way of its performing its office. After it has 
entered the micropyle and penetrated the nucellar epidermis, 
and fertilization, has taken place, those changes begin which 
constitute the 
Development of the seed. After a general comparison of 
this process with what occurs in other seeds, we may proceed 
to a detailed discussion of the fate of each part of the ovule. 
It may be useful to recall that ordinarily the seed-coat is 
developed from the integument or integuments of the ovule, 
while the body of the seed is composed of tissues formed 
within the embryo-sac or of these and nucellar tissue, the 
chalaza playing an inconspicuous part. In Cannct we have 
seen that about half of the ovule consists of chalazal tissue at 
the time of fertilization, and we shall find the proportion 
steadily increasing. This interpretation is based on the 
current definition of the chalaza as 4 the transverse zone from 
which the single or the two true integuments spring V and of 
the nucellus as 4 der oberhalb des inneren Integumentes 
liegende Theil des Eichens 2 .” Such a distinction is, at best, 
more or less arbitrary, but that here indicated seems the 
most natural as well as the most simple. 
At the time of fertilization the ovule is about -5 mm. in 
length from micropyle to base. By the time it reaches 
a length of -8 mm., the micropyle has become quite closed, 
the base of the embryo-sac has broadened so that it is even 
wider than the upper end, and there begins to appear a sharp 
constriction of the funiculus penetrating from its outer side 
at about the level of the mouth of the micropyle (c, Fig. 5). 
Below this constriction is a distinct lip which pushes rapidly 
upward and inward as the constriction encroaches upon the 
vascular bundle (e, Fig. 6). When the length of the young 
seed has reached 2 mm., this lip has nearly met the lip 
formed by the free end of the outer integument of the other 
side, and there protrudes from between them the remnant of 
1 Sachs’ Text-Book, second Engl, ech, p. 571. 
2 Luerssen’s Handb. d. med.-pharm. Bot., Bd. II, p. 258. 
