358 
PHYSIOLOGY. 
BOOK II. 
CHAPTER X. 
OF THE SEED. 
The action of the seed is confined to that phenomenon which 
occurs when the embryo that the seed contains is first called 
into life, and which is named germination. 
If seeds are sown as soon as they are gathered, they gene- 
rally vegetate, at the latest, in the ensuing spring ; but, if they 
are dried first, it often happens that they will lie a whole year 
or more in the ground without altering. This character 
varies extremely in different species. The power of preserving 
their vitality is also variable : some will retain their germi- 
nating powers many years, in any latitude, and under almost 
any circumstances. Melon seeds have been known to grow 
when 41 years old, Maize 30 years. Rye 40 years, the 
Sensitive plant 60 years. Kidney beans 100 years. Clover 
will come up from soil newly brought to the surface of the 
earth, in places in which no clover had been previously 
known to grow in the memory of man, and I have at this 
moment 3 plants of Raspberries before me, which have been 
raised in the garden of the Horticultural Society from seeds 
taken from the stomach of a man, whose skeleton was found 
30 feet below the surface of the earth, at the bottom of a 
barrow which was opened near Dorchester. He had been 
buried with some coins of the Emperor Hadrian, and it is 
therefore probable that the seeds were sixteen or seventeen hun- 
dred years old. 
The chemical action of seeds has been well explained by 
De Candolle, to whom, however, the recent observations by 
Edwards and Colin were unknown. 
Water, heat, and atmospheric air (or at least oxygen) are 
the conditions without which germination cannot take place. 
If any one of them is abstracted, the other two are of no 
