444 



gave chlorinas. vaiaVirated plants and normal trreens in the 

 ratio 1 : 3 : 12. The plants used in these crosses were known to 

 be constant, In one experiment a cross between typica and 

 chlorina gave in F 2 63 green, 4 variegated and 3 chlorinas. Here 

 also the chlorina form was known to be constant. This unusual 

 behavior is explained by Professor Correns in the following 



The occurrence of normal greens amongst the progeny of 

 variegata is due to the revival of a latent factor for green (G). 

 The color factors present in the various types are assumed to be 

 G = presence; g = absence (or latency) of green factor. 



V = presence; v = absence (or latency) of variegata factor. 

 C = presence; c = absence (or latency) of chlorina factor. 



V is epistatic to C. 



G is epistatic to V and C. 



Variegated races have the formula gVC (or gVc). 

 Chlorina races have the formula gvC. 



Normal green races have the formula GVC (or GvC, or GVc, 

 or Gvc). 



GVC + gVC, in which F 2 3 -m-n to 1 variegated; or 

 GvC -f gvC, in which F 2 = 12 green, 3 V and 1 C. 

 The cross green on chlorina becomes: 



GvC + gvC, in which F, = 3 green to 1 chlorina ; or 

 GVC -f gvC, in which F 2 = 12 green, 3 V and 1 C. 

 The cross variegated on chlorina becomes 

 gVC + gvC, in which F 2 = 3 V + 1 C. 

 The cross between the very distinct species Mirabilis Jalapa 

 variegata and M. longifolia typica give hybrids that are quite 

 alike in F„ but highly variable in F„. Yet all the characters 

 involved appear to " Mendelize. " For instance: green and 



habit'form Mendelian characters.^ ^ StatUre ' ***** ^ 



In contradistinction to the white margined P. zonale studied 

 by Baur, a white margined form of Lunaria annua studied by 

 Professor Correns reproduced true to seed, and when crossed 

 with a green leafed form the margin behaved as a recessive 

 Mendelian character. 



A recent article by Whitney in the Journal of Expert mental 

 Zoology* is of interest in connection with the type of heredity 



