TROPOPHYTES 63 
(Figs. 59, 60). The flower is also there, and so far 
developed that all its different parts may be quite easily 
recognized and separated. In this bud-like condition the 
plant hibernates out of harm’s way, protected from wind 
and weather. As soon as the frost is gone, and the first 
warm days of spring arrive, the little shoots break from 
their bulbous cradles and grow into the air. In a short 
space of time—about two months—the plant has flowered, 
set its seeds, and died down again to the ground. 
To what conditions of climate is such a life as this 
adapted ? Clearly to one where the unfavourable season 
is long and the vegetative season very short. Some of 
our bulbous plants, both native (snowdrop) and alien 
(hyacinth), are the first flowers of spring. Plants which 
depend upon seed for their renewal require a warmer 
temperature for germination than buds require for growth. 
They must therefore wait a little longer, till the spring is 
more advanced. This delay is immaterial when the 
vegetative season is long, but when it is short it is im- 
portant that the plant should start on its career as soon as 
possible, and, like the snowdrop, take advantage of the 
first warm days of spring. 
Most of the bulbs and corms which are cultivated come 
from the dry and sunny parts of the world. The narcissus 
is a native of the Mediterranean region, lilies come from 
Asia Minor, tulips from Siberia, and the gladiolus from 
South Africa. In these countries the middle of summer, 
besides being dry, is very hot, and where this is followed 
by a long, hard winter, as in Siberia, the vegetative season 
is reduced to the spring. When the drought of summer 
comes, most of the ground-flora perishes, and among its 
earliest victims is the bulbous plant. 
Marsh-Plants.—These plants live in a soil which is 
always saturated with water, but the greater part of their 
leaves and stems is in the air. Since water is always 
abundant, they naturally show many of the characters 
of water-plants (e.g., large internal air-spaces), and most 
of them may be submerged for a long time without injury. 
On the other hand, they agree with land-plants in pos- 
sessing a good vascular and mechanical system, for they 
draw their water from the ground, and their assimilating 
organs are exposed to the air. The air over the marsh is 
sometimes dry, especially when the wind is blowing. 
