84 



STUDIES IN SEEDS AND FRUITS 



seeds and behaving hygroscopically. Such is the change that 

 impermeable seeds undergo in the air when their coats are 

 injured ; but this is the natural end of all such seeds in the 

 soil. It is the loss of their impermeability, according to 

 Professor Ewart, that brings the resting life of Acacia seeds 

 in the surface -soil of the Australian forests to a close, 

 leaving no choice between germination and death. The 

 earlier seeds to swell in his experiments were, as he observes, 

 mostly dead. 



Similar indications were at times presented in my long 

 weighing experiments on impermeable seeds. In Chapter X, 

 which is devoted to the fate of seeds as indicated by the 

 balance, I refer to the gradual increase of weight, extending 

 over a year or more, of seeds of Entada scandens and Guilandina 

 bonducella that displayed slight defects in their coats. 



One may perhaps be permitted to slacken for a while the 

 reins that control the fancy whilst reflecting on the mysterious 

 development of this condition of ultra-dryness in impermeable 

 seeds in association with the completely suspended vitality of 

 the embryo. If, when we come to discuss this subject in its 

 general bearings in a later chapter, it loses a little of its 

 mystery, we shall still, I venture to think, regard the im- 

 permeable seed as one of Nature's indications of the direction 

 in which speculation should be aimed in discussing the extra- 

 terrestrial or cosmic aspects of plant-life. If such a seed as 

 is presented to us now will not withstand the strain of the 

 ages, it suggests to us in more ways than one the type of 

 plant-organism that might withstand the test. It seems to 

 show us how a plant in a state of suspended vitality might 

 tide over great periods of time not only on this planet, but 

 on others where different conditions prevail. 



Such a seed appears to be almost unconditioned when 

 contrasted with a permeable seed, which is very much in 

 touch with its surroundings, and responds closely in its 

 changes of weight to the varying hygrometric states of the 

 atmosphere. The life of the embryo of a permeable seed 



