::> mOTAXICAL GAZET GIST 



of a margin is dominant over its absence. It is probable, therefore, 

 that the white margin is doe to the presence of an inhibitor whose 



; - 

 In 1911. among 73 pedigreed families of Papasxr Rkeeas grown 



- 



between plants of which the presence or absence of a margin had 

 been recorded, and of winch at goodly proportion of the offspring 

 were capable of being similarly recorded, Tne rest either had 

 white-flowered parent whose possession (or lack) of a 

 could not be determined by inspectkm, or for some other reason one 

 or both parents or die offspring could not be safely characterized 

 with respect to margins. Of the 45 famines having the margins 

 of parents and offspring recorded. 3 represented crosses between 

 plants both of which had margined petals, 17 were from crosses 

 between one margined and one unmargined parent, and ~ - 

 salted from iiulings beUveai plants none of which had margined 

 petals, Tke three families finoin matings between maigined parents 

 consisted of 236 individuals, including in each family a mixture of 

 plants with margined and with unmargmed petals. Records 

 of the margins were often impossible, owing to the interference of 

 other factors not yet fully investigated, so that the numbers 

 of each type of offspring have no special significance in the present 

 connection and they will be reserved for discussion at another 



Of the .17 famines produced by mating plants with margined 

 and with unmargined petals, 12 were composed of a mixture of 

 plants, some with margins and some without, 3 contained only 

 plants with mMMipafJ petals, and in 2 families practically all of 

 the individuals had margins. With m*|mg dominant over their 

 absence, only two kinds of famines were to be expected from this 

 of mating, namely, all margined if the margined parent 

 chanced to be homozygous, and mixtures of plants with margined 

 and unmargined petals if the maigined parent was heterozygous, 

 Hie three famines (10272, 1027 _L) in which no 



though ;-;:- of fe parafcs KM] "^rc:". UK :x 



One margined individual was the mother of afl three of these 

 exceptional families. Hie records show that this plant differed 



