TAA i.3.9.23

                                       –           19            –    

           Why one is alive and another is dead we do not know al-

<->though a considerable amount of research work in this branch

of plant physil/<o>logy is now being done, but some complet/<x>e ir-

-reservible biochemical reactions have taken place in the dead

seed, which for some reason have not occurred in the other,

which has just remained dormant and can spring into active life

again at any time.

          It is, then, a question of great interest as to the

extent of time that life can lie dormant in this way without

actually becoming extinct. It is a property which varies nat-

-urally, with different classes of plants, though I believe very

little definite data has been collected as to the length of time

seeds of different type<s> can be dormant. If we include spores

as well as seeds, we find that they are often more resistant

than seeds, though they are, of course, morphologically and 

physiologically, entirely different from seeds. For instance, 

the spores of some spermatophytes, the class of plants which

includes the fer<n>s, are known to be capable of lying dormant for

very long periods. The possible longevity for seeds and spores

will depend, largely on their resistance to <changes of> external conditions.

          You are all doubtless familiar with the "Mummy wheat"

myth; that is to say, the idea that has been abroad for many

years that grains of wheat taken from various tombs in Egypt

have been successfully germinated into wheat plants, thereby

demonstrating that they have retained their virality for

thousands of years. This story is without any basis of fact.

Doubtless, grains of wheat, reputed to be ac<n>ient^sic j have been

brought from Egypt and have germinated, but I am afraid they

were modern wheat grains palmed off on unsuspecting tourists

by unscrupulous natives. Authentic wheat grains from the tombs