288 RELATION OF FORESTS TO THE 



supply an indefinite variety of conditions only some of which will 

 secure the germination, fructification, and continued reproduction of 

 any one or more kinds of plants. 



Seeds are dispersed widely by the wind and rivers and ocean 

 currents, by man and bird and beast ; but in . order to germination 

 there is required for each, within a definite range, heat and moisture 

 and shade ; in order to growth there is required, it may be, some 

 other measure not less definite of moisture and heat and sunshine, 

 and along with these a soil containing certain constituents for each, 

 in a definite state of disintegration, and in definite states of combma<- 

 tion ; in order to the flowering, and again in order to the fruiting, and 

 yet again in order to the conservation of the seed in the soil, on until the 

 period of germination, there are required a succession of definite 

 varying measures of heat and sunshine and moisture : the range of 

 each may be more or less considerable, but still it is limited by ex- 

 tremes beyond which it cannot pass without fatal effects to the re- 

 production of the plant. 



If the seed have decayed before reaching the spot where it finally 

 rests, if there it be eaten by bird or beast, or if the germ be destroyed 

 or be consumed by some insect, it will never germinate. If through- 

 out the various stages of growth and reproduction which I have 

 referred to, and the intermediate stages connecting these, there be at 

 any time too much moisture, or too little, too much heat or too 

 little, too much sunshine — for the effect of this is not confined to 

 the production of heat alone— or too little, the plant — be it herb, or 

 grass, or bush, or tree — will not be reproduced ; and be it noted the 

 definite measure of heat and moisture and sunshine are not the same 

 throughout but vary in a definite order of progression ; and should 

 these fail at any subsequent period, at any point of the progression, 

 this will be fatal to the continued reproduction of the plant, be it 

 grass, or herb, or bush, or tree. 



Did occasion serve I could produce illustrative cases in point. 



And it begins to appear that if, when the seed of a tree was borne 

 to any spot by the winds, or by the waves of the sea, or by the cur- 

 rent of a stream, or by bird or by beast, there was on that spot 

 either excess or deficiency of moisture the seed would not germinate. 

 Other pre-requisites there are, but with these others these. To many 

 seeds the stagnant pool and the arid sand would be equally fatal but 

 the rainfall evaporating and draining off by infiltration and ruisselle- 

 ment all in excess of what the soil could retain by its hydroscopicity 

 and capillary attraction, would supply the very amount of humidity 



