LATENT LIFE 177 
changes, and yet it is not dead. For in a few days 
we may revive it into vigor, or may nurse into 
lively development the cyst or germ which it in- 
closes. The riddle stares us in the face in every 
bag of dry seeds. In what state is the life of these 
seeds, for most of them are alive in this sense at 
least, that they can in appropriate conditions give 
rise to living plants? This brings us to consider 
the remarkable experiments recently made by M. 
Paul Becquerel. 
One of the first results of Becquerel’s work was 
the demonstration of the extraordinary imperme- 
ability of the envelopes of many seeds. Thus the 
coats of the naturally dried seeds of the lupine re- 
main impermeable to air and other gases for two 
years. They are also impermeable to liquids, such 
as absolute alcohol, ether, and chloroform. The 
gases and liquids readily soak into seeds of lupine, 
peas, and beans whose coats have been taken off, 
but when the coats are left on they are for a long 
time gas-proof and liquid-proof. Very careful 
experiments with naked seeds of peas, beans, and 
lupine, in their natural state of dryness (that is, 
still containing a minute quantity of water), showed 
that after a certain time in darkness they absorb 
traces of oxygen and liberate traces of carbon 
dioxide. But this gaseous interchange is probably 
due to a simple chemical oxidation at the surface 
of the seed and not to an attenuated respiration. 
It is certain that seeds do not necessarily lose their 
power of germinating though they have been kept 
