6 Humphrey. — The Development of the 
epidermal layer (i. i., Fig. i), which usually form a double row 
encircling the base of the nucellus. The growth thus begun 
is continued so that a ridge of tissue results, which finally 
encloses the whole nucellus except at the micropyle, forming 
the inner integument of the ovule (i. i., Figs. 2 , 3, 4). This 
coat is usually, as in all the Scitamineae studied, two cells in 
thickness. It begins to be formed slightly earlier on the 
outer side of the ovule than on the side turned toward the 
funiculus (Fig. 1). As its development progresses, and when it 
has reached perhaps half of the height of the nucellus, there 
arises in the same manner from the epidermal cells just at its 
base the outer integument. This has a thickness of several 
cell-layers, as in all the Scitamineae examined, and, at the 
time of fertilization is of about the same height as the inner 
integument, so that the long and narrow micropyle is formed 
wholly by the latter (Fig. 4). The outer integument is in- 
terrupted by and fused with the raphe as in other anatropous 
ovules. Meanwhile the vascular bundle has developed in the 
funiculus, and downward to the chalaza of the ovule. The 
embryo-sac at first lengthens slightly with the growth of the 
nucellus, and then rapidly broadens at its micropylar end, 
destroying the tissue lying between itself and the nucellar 
epidermis, and acquiring the clavate form which it has at the 
time of fertilization (Fig. 4). At this time, however, not all of 
the nucellar tissue is suppressed ; but the sac is separated 
from the nucellar epidermis by one or more cell-layers, except 
at its apex. The nucellar and chalazal portions of the ovule 
are now about equal, and the lower end of the embryo-sac has 
already penetrated into the chalaza. The fusion of the polar 
nuclei to form the endosperm-nucleus (esp. n ., Fig. 4) and the 
developed egg-apparatus (egg) have been observed, but the 
antipodal cells were not well seen. In view, however, of 
Guignard’s observations (’ 82 ) of the usual phenomena within 
the embryo-sac of Carina , it was not thought necessary to 
pursue the subject in detail. The mature ovule is so far 
turned upon itself that its micropyle lies almost in contact 
with the funiculus, and the course of the pollen-tube is neces- 
