398 WILLIS : MORPHOLOGY OF THE PODOSTFMACEÆ 
remains tightly held down within the hard persistent bracts, 
and the seeds germinate in situ and break through the thin 
membranous fruit wall. The embryo (PI. XXXVI., fig. 9) is 
short, straight, and thick, and from 0*5 to 0*75 mm. long, of 
which length the cotjdedons form two-thirds. 
The germination is fairly rapid. The hypocotyl emerges 
from the testa and bends downwards to the substratum, 
becoming attached in the usual way, w^hile its base becomes 
somewhat flattened or tuberous (PI. XXXYI., fig. 10). 
Haptera are rare ; one case was found with haptera at the base 
of the foot formed by the hypocotyl. Fig. 14 shows two 
seedlings emerging from a capsule more or less embedded 
in the remains of the old thallus, bracts, &c. 
The cotyledons spread out at once ; they are not opposite 
to one another in this species, but stand at an angle of about 
135°, so soon as they are open. Thus the dorsiventrality of 
the mature plant shows itself in the very earliest stages of its 
life. The notch between the cotyledon-bases runs lower- 
down, i.e.y nearer to the foot of the hypocotyl, on the anterior 
than on the posterior side of the expanded embryo, but I am 
not able to make out whether the same is the case in the 
ripe embryo in the seed. The wider angle between the 
cotyledons is usually upwards, the backs of the cotyledons 
being almost appressed to the substratum. The cotyledons 
are wider and stouter in proportion than ordinary leaves, 
and are not hairy. The apex is acute, and the base vertically 
thickened as may be seen in the figures ; the upper side is 
very slightly concave. 
Figure 10 shows a very young seedling ; the cotyledons are 
spread out with their lower sides almost against the ground, 
and in the larger angle between them the thallus is emerging, 
slightly above the base of the flattened “ foot.” The 
direction of starting does not, as one might expect, bisect 
the large angfe between the cotyledons, but lies as a rule in 
a line with and opposite to one of the cotyledons, as may be 
seen in several of the figures, especially well in fig. 11. In 
some cases two thalli are formed from one hypocotyl, as 
