Seed in the Scitamineae . 
1 3 
lid is punched out at the micropylar end, permitting the escape 
of the embryo. The circular form of the lid appears to be 
determined by the firm ring-like collar surrounding the apex 
of the embryo-sac. The line of least resistance is evidently 
at its inner face, so that it comes to form a close collar about 
the neck connecting the growing part of the embryo without 
the seed, with the absorbing organ that remains within. Except 
at the germinal slit, I have been unable to recognize any sign 
of preparation for the cutting out of the lid. Yet it seems 
remarkable that, without some differentiation, it should always 
show the clean-cut inward bevel it possesses. It may be ob- 
served that Hegelmaier’s (’7 4) statement that the whole of 
the testa formed from the original integuments of the ovule 
constitutes the lid is here shown to be inexact. This lid was 
early observed by Mirbel (TO), and more recently by Gris (’64), 
Hegelmaier (’74), and Klebs (’85). Its existence is denied by 
Tschirch (’90), who states that there is merely a sickle-shaped 
break in the sclereids of the coat, formed by the separation of 
the lower ends of the sclereids. The name £ sclereids ’ is here 
evidently applied to the cells of the palisade-layer. This 
statement concerning the absence of a lid in Canna is correct 
only in so far as it refers to such a preformed one as is found 
in many other Scitamineae. 
With the exception of a kite-shaped region at the micro- 
pylar end, which includes the germinal slit (Fig. 13 ), the 
surface of the testa is thickly marked with tiny dots, as seen 
by the naked eye. Moderate magnification shows these to 
be true stomata, as was first pointed out by Schleiden and 
Vogel (’42). In the early stages of the development of the 
seed, their guard-cells are living, and they are evidently capable 
of performing the functions of stomata (Figs. 20 a, 20 b, PI. II). 
As the outer layer becomes transformed into a palisade-tissue, 
the guard-cells also lose their cell-contents and become 
rigidly fixed in the wide-open position. They remain but 
slightly sunken below the surface, but their air-cavities 
become greatly lengthened by the growth of the palisade- 
cells (Fig. 21 ). This occurrence of stomata in the seed-coat 
