The Origin of Striped I'loiccrs. 115 



On the other hand a certain percentage (often 6% and 

 more) of the phmts raised from the seeds of stri])ed 

 flowers and especially of sectorial l)ranches are usually 

 unif(Mni Ijlues.^ 



The phenomena of segregation whicli we liave been 

 describing are quite common in striped flowers, and any 

 one can observe them in Dahlia variabilis striata (Vol. 

 I, Fig. 14, p. 54), Mirabilis Jalapa, Verbena and many 

 other favorite garden flowers. Sectorially colored flow- 

 ers appear to manifest a tendency towards a simple pro- 

 portion between the two parts. Frequently exactly half 

 of the flower is atavistic, sometimes a quarter or three 

 quarters. I observed the proportion % in white and red 

 striped tulips and in partially dark blue and partially pale 

 blue flowers of Iris xiphioides, etc. In these cases the 

 various types frequently occur on the same plant, or in 

 the case of plants grown from bulbs, on examples raised 

 through vegetative propagation from a single original 

 bulb; for instance on the tulips and Iris just mentioned 

 there were also flowers of which one-half of each was 

 atavistic. 



Sectorial variability often occurred in my cuhures, 

 as for instance in the flowerheads of Helichrysuni brac- 

 teatiim and the flowers of Papaver nudicaule (Fig. 20), 

 in both of which cases stripes or sectors of the color 

 belonging to the parent species were superimposed on 

 the paler background of the variety. A common balsam 

 {hnpatiens Balsamina) whose flowers were usually white 

 with fine red stripes bore a branch with red flowers only 

 in my garden. The whole breadth of the fasciated stem 



^ A point of great interest to investigate would be the relation 

 between sectorial variability and cell division in the vegetation cone ; 

 clues which might lead to the solution of many important questions 

 would probably be afforded by such an inquiry. 



