534 



The Journal of Heredity 



and a lower layer of white cells. An 

 illustration of this is to be seen in the 

 x-ariej^ated-leaved geraniums which arc 

 familiar to everyone. This type of 

 variegation has never as yet appeared 

 in the offspring of my pigweed. 



AVjout half of the seeds of the trans- 

 planted ]3igweed were planted in sterile 

 soil in the sjjring of 1913. A few seeds 

 from all green branches were saved 

 separately. The results are given in 

 Table 1. 



T.VHLb; 1. V.\KIEG.\TED PlGWEEU 1. 



Seedlings 



Green plants .... 

 Variegated plants 

 White plants .... 

 Total 



The contrast between the seedlings 

 from the whole plant and those from the 

 green branches alone seemed to be too 

 great to be due to chance so the experi- 

 ment was repeated by saving the three 

 most vigorous variegated seedlings which 

 were called lA, IB, IC. Each plant 

 was ])laced in a separate box of earth 

 and protected from outside ]jollen as 

 far as possible by a cage with a glass 

 top and two layers of heavy muslin on 

 the sides. 



An all green slip from lA was rooted 

 in the house and its seed saved sep- 

 arately. As it was impossible to raise a 

 pxxTC white seedling or an all white 

 slii), I saved some seeds by hand from a 

 pure white branch on lA. In the other 

 two pigweeds the white and green 

 tissues were so mixed that it was diffi- 



cult to save seeds from the white tissue 

 alone without including some from the 

 green portions of the plant. The white 

 tissue was also in much smaller amount 

 in these plants than on plant lA which 

 probably accoimts for the smaller pro- 

 portion of white seedlings which they 

 ])roduccd. A few seeds from the green 

 branches of lA were also saved by hand 

 and most of them planted soon after 

 they were gathered. To my great sur- 

 prise not a seed came up and after 

 standing around for several months, 

 the box met with an accident and the 

 seeds were lost. This showed that the 

 seeds would have to mature before they 

 would germinate so I waited until this 

 spring before ])lanting the rest of the 

 seeds. The results are given in tables 

 2 and 3. 



Table 2. Variegated Pigweed 1A. 



Seedlings 



Mixed seed 



from 

 whole plant 

 No. % 



Seed from 

 lA 

 green slip 



No. % 



Seed from 

 green brandies 

 38 seeds 

 No. % 



Seeds from 

 white branches 

 165 seeds 

 No. % 



Note. The four green seedlings in the right-hand column from seed taken from white branches 

 come probably from wild seeds which were not killed in sterilization of the earth. The earth in 

 this case was boilerl for half an hour with occasional slirrinj.^ in an open pan. In all other cases 

 the earth was baked in a hot oven for at least three hours and then washed with three or four 

 changes of water to remove any injurious substances which might be formed by the heat. That 

 the earth in this box was insufhciently sterilized is shown by the fact that two other weeds, Malva 

 rolundifolia, also appeared in this box. All the other boxes remained free from foreign weeds. 



