8 Humphrey ,—The Development of the 
the funiculus {f Fig. 7). From this time the connexion 
of the seed with the placenta is very slight, mechanically ; 
but the vascular bundle must remain functional for a long 
time, in order to furnish the material for its extensive further 
growth to the seed. We shall see that these lips never fuse 
at the point of entrance of the bundle, but that there remains 
here in the ripe seed a small break in the seed-coat which 
will be called the germinal slit, and which represents, as is 
evident, the combined micropyle and hilum of the ovule 
(g. s., Fig. 8). Meantime the greater proportion of growth 
has taken place in the chalazal region, and this continues to 
be true for some time, as may be seen from the following 
table, which gives average figures for several stages up to the 
full-grown seed : — 
Length of seed . . -So mm. 2*25 mm. 4*50 mm. 9-50 mm. 
Nucellar part . . .38 „ -65 ,, .85 „ 1-95 „ 
Chalazal part . . .42 „ i-6o „ 3-65 „ 7*55 „ 
Per cent, of growth of whole seed 180 / 100 % in % 
„ „ of nucellar part 71 % 31 % 129 % 
„ „ of chalazal s , 281 % 128% 107% 
During this growth the embryo-sac extends downward as 
a broad irregular cavity more or less abundantly lined with 
dead and ragged cell-remains ; as its full size is reached, it 
gradually becomes more regular in form and smoother in 
outline. When the young seed is about 2 mm. long, the 
upper end of the embryo-sac abruptly expands by the 
resorption of the tissue lying between it and the inner 
integument ; that is, of practically all the nucellar tissue. 
This gives the sac a very peculiar form, that of a club-shaped 
body, broadest at the base, connected by a narrow neck with 
a broadly conical head {e. s., Fig. 7). The tissue surrounding 
the neck soon dies and becomes resorbed, so that the neck 
itself is at last only a slightly narrowed region between 
head and body (e. s., Fig. 8). Hegelmaier states ( 74 ) that 
a chalazal cavity is formed independently of the embryo-sac, 
and becomes united with it later by the breaking down of 
the intervening tissue. As to this, it can only be said that 
