260 THE SURVIVAL OF THE UNLIKE. [xiV. 



The second and chief reason for the mainte- 

 nance of this dense population was the fact that 

 each plant grew to a different shape and stature, 

 and each one acquired a different longevity ; that is, 

 they had varied, because they had to vary in order 

 to live. So that, whilst all seemed to have an 

 equal chance early in July, there were in August 

 two great branching red -roots, one lusty ragweed 

 and eighty -three other plants of various degrees of 

 littleness. The third census, taken September 25th, 

 is very interesting, because it shows that some of 

 the plants of each of the dominant species had died 

 or matured, whilst others were still growing. That 

 is, the plants which were forced to remain small 

 also matured early and thereby, by virtue of their 

 smallness, they had lessened by several days the 

 risk of living, and they had thus gained some 

 advantage over their larger and stronger compan- 

 ions, which were still in danger of being killed by 

 frost or accident. When winter finally set in, the 

 little plat seemed to have been inhabited only by 

 three big red -roots and two small ones and by one 

 ragweed. The remains of these six plants stood 

 stiff and assertive in the winds ; but if one looked 

 closer he saw the remains of many les'ser plants, 

 each "yielding seed after his kind," each one, no 

 doubt, having impressed something of its stature 

 and form upon its seeds for resurrection of similar 

 qualities in the following year. All this variation 

 must have been the result of struggle for existence, 

 for it is not conceivable that in less than two 

 feet square of soil there could have been other con- 

 ditions sufficiently diverse to have caused such 



