I.] DISRUPTION OP SPECIFIC TYPES. 39 



farmer sows from five to twenty times more seed than he 

 needs. Some years ago, I sowed seeds according to the 

 recommendation of one of our best seedsmen, and I 

 found that peas would be obliged to stand four- fifths 

 of an inch apart, beets about twenty to the foot, and 

 other vegetables in like confusion. I suppose that of all 

 the seeds which actually come up, not more than one 

 in ten or a dozen, in garden vegetables, ever give ma- 

 ture plants. What becomes of the remainder! They 

 are thinned out for the good of those which are left. 



This simple process of thinning out vegetables has 

 had a most powerful effect upon the evolution of our 

 domestic flora. It is a process of undesigned selection. 

 This selection proceeds upon the differences in the seed- 

 lings. The weak individuals are disposed of, and those 

 which are strongest and most unlike the general run are 

 preserved. It is a clear case of the survival of the un- 

 like. The laborer who weeds and thins your lettuce bed 

 unconsciously blocks out his ideas in the plants which 

 he leaves. But all this is a struggle of Jew against Jew, 

 not Jew against Philistine. ' It is a conflict within the 

 species, not of species against species. It, therefore, 

 tends to destroy the solidarity of the specific type, and 

 helps to introduce much of that promiscuous unlikeness 

 which is the distinguishing characteristic of domestic 

 plants. 



Let us now transfer this emphatic example to wild 

 nature. There we shall find the same prodigal pro- 

 duction of seeds. In the place of the gardener unde- 

 signedly moulding the lines of divergence, we find the 

 inexorable physical circumstances into which the plastic 

 organisms must grow, if they grow at all. These cir- 

 cumstances are very often the direct causes of the 



