PERMEABLE AND IMPERMEABLE SEEDS 85 



depends largely on the conditions in which the seed is placed, 

 and it is ever threatened by many dangers, against which the 

 embryo of an impermeable seed is fully protected. It is 

 immaterial to the young plant enclosed in the hard shell of 

 a seed of Guilandina bonducella whether the seed lies exposed 

 to the sun on a desert or is submerged in a swamp. As 

 compared, then, with the permeable seed, the impermeable seed 

 seems to present to us a relatively unconditioned existence 

 of its embryo. 



Whilst indulging in such speculations it is pertinent to 

 ask which was the prior state of the seed, the permeable or Which is the 

 the impermeable. To this it may be replied that if in past permeable or 

 ages seeds had no rest-period, the matured seed passing on able see"™^' 

 at once to germination, the development of the impermeable 

 state would be of later origin. But the seed-stage may be 

 conceived as the permanent state of plant-life under certain 

 iron-bound conditions, such as may prevail on other planets, 

 and such as may have originally prevailed on the earth. In 

 such a case the seed-stage would represent the plant's response 

 . to the rigid control of contracted life-conditions, whilst the 

 vegetative growth would represent in the production of stem 

 and foliage the plant's response to the expanding conditions 

 of existence. Under such circumstances the impermeable 

 seed would be the older state. 



As the plant-world exists at present, though impermeability 

 has the appearance of necessity, impermeable seeds have to , 

 become permeable in order to germinate. It can, however, 

 be easily shown, and this will be done in a later chapter, that 

 in plants possessing both types of seeds the impermeable state 

 is the goal sought in the seed's development, and that the 

 permeable seeds have their origin in checks to the shrinking 

 process. With such plants the impermeable seed, when 

 beginning to swell for germination, resumes the appearance 

 of the permeable seed. May it not be that impermeability 

 is a cosmic character which, in response to the expanding 

 terrestrial conditions, has largely given place to permeability } 



