Poli/cephalic Popples 395 



nearly all weeding out. I got 120 plants, and 

 among them 30 with full crowns of converted 

 stamens, practically the same number as after 

 the weeding out in the first experiment. This 

 shows that smaller quantities of seed give an 

 equal chance for a greater number of large 

 crowns, and should therefore always be pre- 

 ferred, as it saves both seed and labor. 



Weeding out is a somewhat dangerous oper- 

 ation in a comparative trial. Any one who has 

 done it often, knows that there is a strong 

 propensity to root out the weaker plants and to 

 spare the stronger ones. Obviously this is the 

 best way for ordinary purposes, but for com- 

 parisons evidently one should not discriminate. 

 This rule is very difficult in practice, and for 

 this reason one should never sow more than is 

 absolutely required to meet all requirements. 



Our second point is the manuring of the soil. 

 This is always of the highest importance, both 

 for normal and for anomalous attributes. The 

 conversion of the stamens into pistils is in a 

 large measure dependent upon the conditions of 

 the soil. I made a trial with some 800 flowering 

 plants, using one sample of seed, but sowing 

 one-third on richly manured soil, one-third on 

 an unprepared bed of my garden, and one-third 

 on nearly pure sand. In all other respects the 

 three groups were treated in the same way. Of 



