VITALITY AND GEKMINATION OF SEEDS. 231 



Peas after the vitality of radicle or plumule has been 

 destroyed by the operation of some injurious influence, 

 the remaining part of the embryo (plumule, radicle or 

 cotyledons as the case may be) is in many cases still 

 capable of independent germination. 



The special vitality of the protoplasm of a seed is due to : 



(1) The decreased amount of water which it contains. 



(2) The less complex nature of the protoplasm of the 

 seed. 



The differences between ordinary protoplasm and that 

 of a seed are very marked. Ordinary living protoplasm 

 is very unstable, continually undergoing change, contains 

 much water and is instantly killed by absolute alcohol. 

 The protoplasm of seeds is stable, contains very little 

 water and is not instantly killed by absolute alcohol. It 

 is probable that the "protoplasm" of a seed is not the 

 same thing as ordinary living protoplasm. It may be 

 intermediate between the relatively simple dead proteid 

 and the much more highly complex living protoplasm. 

 The simpler substances into which the protoplasmic 

 molecules of a ripe seed are thus split up do not separate 

 from each other but remain (Kerner von Marilann) within 

 the spheres of attractive influence of their respective 

 molecular groups so long as the seed retains its vitality. 

 When germination occurs a recombination of these groups 

 takes place and living protoplasm is formed. If through 

 any cause the groups of elementary compounds become 

 separated beyond their spheres of attractive affinity no 

 such recombination is possible, i.e., the vitality of the 

 seed has been destroyed. 



The injurious effect of removing the last traces of water 

 which a seed contains is probably due to such a change 

 being brought about, perhaps by the removal of one of 



