THE SEED AND GERMINATION 39 
In some species, the young plant becomes oyer a foot 
in length before detaching itself from the parent tree. 
Still growing, it falls into the mud, and, in the space 
of a few hours, is permanently established. The species 
that grows round the shores of Auckland Peninsula is 
peculiar in the fact that the seed does not fall out of 
the seed case, since the whole fruit detaches itself from 
the tree at one time. The seed does not escape till it 
reaches the water, when, under favourable conditions, 
though no radicle is present, it puts forth several 
slender roots that anchor the seedling to the mud. In 
the proper season, mangrove fruits may be commonly 
seen washing about along the shores of Waitemata 
harbour. When the seed ease is removed the two large 
fleshy cotyledons appear, and the fact that there is no 
radicle may be readily observed. 
GERMINATION. 
Let us now study the circumstances under which the 
embryo or infant plant resumes its interrupted develop- 
ment: in other words, let us consider the conditions 
necessary to germination, as the awakening of the 
seed is termed. 
Moisture.—Every gardener knows that moisture is 
essential to germination. Seeds may be kept for years 
in a dry bag or box and there will be no sign of 
awakening: but only let the bag become wet, and, 
other conditions being favourable, germination will 
at once begin. The seedsman stores his seeds in a dry 
place so that they shall not germinate. 
Experiment 1.—Place various kinds of seeds in 
moist sawdust and others on a dry shelf. The latter 
- will not germinate, but 1f the weather is not too cold 
the former will. 
Warmth is necessary. Everyone has observed that, 
in the colder parts of New Zealand, where a piece of 
