254 



Inheritance in the Gh'oimdsel 



instead of being veiy obscurely 3-toothed at the tip, the ligules were 

 often divided down to the basal tubular portion into three (sometimes 

 two) long narrow segments. The capitula, as a whole, thus acquire a 

 tasselled or fimbriate character. (PL XVII, figs. 19 and 20.) 



The study of the inheritance of this character is beset with diffi- 

 culties. Although these have not yet been surmounted, it will be of 

 interest to record the results hitherto obtained. No. 43 was selfed and 

 a few seeds ultimately collected. It was noteworthy that the basal 

 branches of this plant produced normal flowers, causing me to suspect 

 that the anomalous fimbriate appearance was due to Aphis attack. 

 Fortunately the experiment wa,s carried on, and it was soon found that 

 perfectly healthy plants quite free from Aphis might be fimbriate. The 

 nature of the progeny of this plant is given in the following table : 



1909. F.. . 



1910. F3. Exp. 4.5. 



No. 43, fimbriate, sulfed. 



17 plants, of these three were Rr plants. 

 3 Deducting these, there were left 



14 plants, all RR 



9 fimbriate 



I 



I 

 No. 4 selfed 



I 



No ripe seeds 

 obtainable. There- 

 fore self-sterile 



1911. Fj. Exps. idandil. 



I 

 5 non-fimbriate 



I 

 No. 17 selfed. Exp. 47. 



Exp. 46. No. 6 not selfed 



49 plants 



47 plants, all nun-finibriate 



I 

 22 fimbriate 



27 nou-fimbriate 



It is clear that the fimbriate character is inherited, and it may be 

 assumed that a corresponding ftictor F suddenly dropped out of the 

 constitution of the original plant. No. 43. The new character, repre- 

 sented let us say by the recessive factor/", as far as known, does not 

 occur in any other local form of Senecio. Yet it probably occurs in 

 many Compo.sitae, e.g. in chrysanthemums. Ultimately time may be 

 found to trace its development and to make the necessary comparative 

 studies. In the meantime, we may safely assume that we have to deal 

 in this case with a mutation (and possibly a segregation also). 



It is clear that the plants are either self-sterile or very infertile 

 to their own pollen. In this connection it may be stated that on 



