12 Humphrey . — The Development of the 
its histological details from the rest of testa. We have seen 
that the end of the original inner integument is bent upward 
before the differentiation of the chalazal integuments. In 
accordance with this we find that the inner face and the 
extreme lower portion of the outer face of the collar are 
formed from the true integument (i. i., Fig. 14), while the 
rest of the outer face is formed by chalazal integument. 
Before the ripening of the seed the integument of the inner 
face is compressed to a mere line, and the double layer of 
cells which is elsewhere seen is here unrecognizable. Thus 
the true inner integument of the ovule becomes practically 
obliterated, with the exception of the bit of its originally lower 
end which is upturned at the lower edge of the collar. Beneath 
the compressed inner integument occurs a dense small-celled 
layer not elsewhere found (x, Fig. 14). The nutrient layer is 
here much less compressed than in the rest of the testa, but 
is readily disintegrated when the seed is ripe. The sclereid 
layer occurs in the collar as elsewhere, and, with the dense 
inner layer, forms its substantial portion. In but one region 
can any discontinuity in the tissues of the testa be observed. 
From the tip of the embryo-sac a break through all its layers 
can be traced to the surface, where it is recognizable as the 
tiny crack whose morphology has been already pointed out, 
and which has been called the germinal slit (g. s ., Fig. 14). 
As has been shown, the funiculus is attached at this point 
(Fig. 1 1); and if a seed be carefully detached from the placenta, 
its whole micropylar end is found to be covered by a structure 
which greatly resembles some of the arillar developments of 
other Scitamineae (f Fig. 12). Examination shows, however, 
that it is a fimbriate outgrowth from the free portion of the 
funiculus, quite external to the seed. 
When germination begins with the swelling of the embryo 
in the seed, the pressure must soon cause a rupture at the 
weakest point. This is evidently the point which, for this 
very reason, we have called the germinal slit. As this crack 
is stretched open, the testa breaks on either side, and this 
break follows a quite circular course, so that a small disk-like 
