i 



A. H. Trow 251 



Investigation of a Colouk Character in the Floweks, 

 The colour of the multicaulis flowers was, in the first generation 

 raised, appreciably different from that of the other forms, and it was 

 described iu 1908 {Flora of Glamorgan) as of "a soft yellow." It was 

 not anticipated that so subtle a distinction would admit of further 

 analysis. However it can now be shewn that the ray florets may, 

 in certain types at least, be either yellow or cream coloured, and that 

 cream behaves towards yellow as a recessive. It will be of interest to 

 produce the evidence for this statement, especially as it demonstrates 

 that there must be a second factor which acts when present along with 

 that for cream colour in such a way as to inhibit more or less completely 

 the development of the cream-colour character. 



Eocp. 15. Multicaulis was crossed by erectus, radiatus in 1907, and 

 461 plants of the F2 generation were examined in 1909. At a late 

 stage in the examination, some of the RH plants attracted notice on 

 account of the cream colour of the flowers. At first the colour was not 

 treated as a character deserving of much attention, especially as it was 

 not perfectly uniform in all the cream-flowered individuals. The total 

 number of creams of which a definite record was kept is five, but there 

 were certainly more. Fortunately seeds were saved from the two most 

 typical creams — Nos. 174 and 346. These plants, however, had not 

 been properly selfed. The nature of the progeny of these two plants is 

 given below in the form of genealogical tables. 



1909. F2. No. 174. Cream, not selfed. 



I ... 



1910. F3. Exp. 31. 33 plants, of which 5 were NR hybrids due to ordinary crossing. 



5 Deducting these, there were left 



28 plants, all Cream, of which No. 5 was selfed. 

 No. 5 



1911. F4. Exp. 32. 47 plants, all cream. 



1909. F2. No. 846. Cream, inadequately eelfed. 



I 



1910. F3. Exp. 33. 108 plants, of which 4 were NR hybrids. 



4 Deducting these, there were left 

 104 plants, all RR. 



r^ 1 



97 plants, Cream 7 plants. Yellow, no doubt due to the inadequate 



I seliSng. 



No. 8. Selfed. 



I 

 1911. Ft. Exp. 34. 49 plants all cream. 



