262 



Inheritance m the Groundsel 



TABLE XIIL 



Types 



Exp. 

 Exp. 60 



Wo. 

 29 



Exp. 65 34 



Exp. 66 35 



Exp. 67 36 



Exp, 64 33 



Cross 



Lanuginosas x 

 praecox 



Lanuginosus x 

 multicaulis 



Lanuginosus x 

 multicaulis 



Lanuginosus x 

 multicaulis 



Lanuginosus x 

 multicaulis 



Hair 



type 



Hh 



Ray No. of 

 type plants 



rr 97 



HH 

 22 



90 23 



Hh hh 

 49 26 



44 23 



Hh RR 96 31 (H«) 33 32 



Hh RR 49 13(H') 36 H^ 



Remarks 



Very hairy individuals 

 present in HH 



The hair in HH plants 

 relatively weak 



The hair in HH plants 

 well developed 



The H' plants as hairy 

 as lanuginosus 



Hh Rr 49 14 



20 15 



Hair fairly well 

 veloped 



de- 



plants were apparently of the same physiological constitution as lanu- 

 ginosus — the soil did not suit them — the 36 hairy individuals were fairly 

 well adapted to their environment. It was doubtless no accident that 

 caused one-fourth of the plants of this colony to behave in this way. The 

 plant selected as the parent for this colony happened to be an individual 

 with the constitution Yy. The thirteen very hairy plants were yy in 

 constitution. This explanation may possibly suffice to account for the 

 occurrence of a certain percentage of weakly plants in other cultures 

 derived from the cross lanuginosus x multicaulis. These weaklings are 

 recognisable in the seed-pans and boxes, and invariably perish when 

 planted out. May they not have been to a great extent the yy plants 

 of the different generations ? They are always so hairy that the possi- 

 bility has always been kept in mind that ill health in itself, whatever 

 its cause, promotes hair development by its indirect influence on certain 

 regulating factors. These weak, hairy plants were carefully grown and 

 watched in 1912, and proved to be invariably long-styled and relatively 

 infertile. Fig. 17, PI. XVII shews the capitulum of one of them. 



TABLE XIV. 



Remarks 



No rr plant was very 

 hairy, although 

 2 were placed 

 under H^ 



Rather weak type of 

 H^ hair. Unaf- 

 fected by segre- 

 gation of Rr 



Hair tending to dis- 

 appear with age ; 

 unaffected by the 

 segregation of Rr 



