20 Flower Colour and Characters of the Opium Poppy 



a culture which, according to the time of the visit, may appear pure to 

 one or other of three forms, one of which is not, in reality, a pure form 

 at all. Before this correlation was established a number of cultures 

 were noted as b%ing pure to the earlier form, and the counting dis- 

 continued a few days before the second, or intermediate, form first made 

 its appearance. The table illustrates the simpler examples of this 

 phenomenon, which is, however, equally well shown in the more complex 

 cultures. For instance, a culture containing a complete mixture of 

 Groups I to V will at first appear to be a mixture of P, RP, RB, PP 

 and R forms; later, as these disappear, VL, LP, PW, PPG, PP^, and 

 GPG take their place, and ultimately these two are replaced by the 

 W, MP and PL forms. 



Before leaving this subject it may be noted as a fact, of which no 

 explanation can be offered, that this correlation has failed to appear in 

 the F2 of the crosses which have been made, and which would be 

 expected to show it. Such a total disappearance in the progeny of the 

 crosses of a phenomenon, which is of universal occurrence in the single 

 plant cultures, can only be regarded as extraordinary, requiring for 

 explanation a more detailed study of the history of the parents than has 

 yet been undertaken. 



This preliminary review has indicated one or two points which are 

 not without interest, and which, now that the war is over, will, it is 

 hoped, form the subject of further investigation. 



EXPLANATION OF PLATE I. 



The letters given in parentheses are the short-hand designations used for the various 

 colour forms in the text. Fuller descriptions of these forms, together with the factorial 

 constitutions in 30 far as they have been determined, will be found on pp. 4 — 6. 



