SEEDLING 
Germination. A considerable number of seeds were germinated 
in the laboratory. Seeds gathered in October, at the end of the 
flowering season, first began to germinate in December, and from 
that time on seedlings appeared intermittently. It is evident, there- 
fore, that the seed requires a short period of rest before the new 
growth begins. 
Seedlings were grown either in mud from their native habitat, 
or in clean-washed sand, the latter being preferable, on account 
of the numerous algae, bacteria, &c. which soon develop in the 
former. The salt water used was taken from New Haven Harbor. 
Irmisch (1858) noticed in the achene of Ruppia rostellata a small, 
slightly swollen, elongated area which he claimed was the place of 
exit for the cotyledon and root on germination. Such a spot occurs 
also in Ruppia maritima, but | have been unable to ascertain def- 
initely if this is the region which is ruptured at germination. In 
most cases a more or less triangular area of the hard, dark-brown 
covering is pushed off and the cotyledon and adventitious root 
make their appearance (PI. XV, fig. 120). In figure 121 the whole 
pericarp has been purposely removed to show the enormous hypo- 
cotyl. 
Figure 120 shows a seedling about three days old. Here the 
three vegetative organs are disclosed: the first foliage leaf is devel- 
oped from the cotyledon, which becomes green; the stem is formed 
by the elongation of the hypocotyl; and the root grows rapidly 
downward, becoming abundantly furnished with root-hairs. 
In the case of the root, it is interesting to note that it exhibits 
a general tendency to first grow upwards for a short time, only 
later turning downward. The proportional growth of roots and 
leaves seems to vary considerably (Pl. XV, figs. 120, 121). 
Formation of Rootstock. Text-figs. 32 and 33 are drawings— 
natural size—of seedlings grown in the laboratory in washed sand 
and harbor water. The seeds were collected in January, being 
extracted from mud taken from the bottom of a ditch where Ruppia 
maritima grows and fruits abundantly, many of the parent plants 
being even at that time in a green, flourishing condition. On 
being placed in a warm room, germination occurred in a few days. 
