Its indica- 

 tions of life 

 in other 

 worlds. 



452 STUDIES IN SEEDS AND FRUITS 



of a plant-organism. However this may be, there is a promise 

 almost of eternity in the life both of the seed-embryo and of 

 the tall Sequoia, though both are ever liable to the accidents of 

 their surroundings, the seed after its repose of a hundred 

 years, and the tall conifer after an existence'of centuries. 



Although we possess a scale of plant-development 

 beginning with the seed and ending with the fully-grown 

 plant, yet it by no means follows that our terrestrial scale 

 presents us with the beginning and the end of the possibilities 

 of the plant's development, or that we have in the seed the 

 absolute minimum or in the tall forest tree the absolute 

 maximum. Yet, looking just beyond the terrestrial scale at 

 either of its limits, we obtain indications of plant-development 

 in other worlds. Thus, if at the maximum end of the scale 

 we emphasise or intensify the life-conditions of the Sequoias on 

 the Sierra Nevada, so vividly portrayed by Clarence King, we 

 may be reproducing the conditions under which plants exist in 

 another planet. Let us similarly extend the terrestrial scale a 

 little at the minimum end, and it will not be difficult to 

 imagine a world where vegetable life is only represented by 

 plant-organisms in the seed-stage or by plants that do not 

 pass beyond the cotyledonary stage of the West African 

 fVelwitschia. 



There is no necessity to suppose that other worlds possess 

 forms of plant-life altogether outside the terrestrial scale. All 

 possibilities should be indicated on our sphere. We get there 

 indications of the possible forms of plant-organisms on a planet 

 presenting the surface conditions of the moon, where the 

 conditions for plant-life, as we know it, are reduced to a 

 minimum for which the seed-stage appears to be alone suitable. 

 We can also thus obtain indications of the possible forms of 

 plant-life on planets where the present terrestrial conditions 

 are greatly extended as regards the denseness of the cloud- 

 envelope, humidity, and high temperature, where plants like 

 the huge Calamites of the Coal Age may flourish and where 

 the rest-period is unknown. Or, again, these conditions of 



