R. P. Gregory 



311 



investigations should be made, with the object of tracing back these 

 differences between the plastids to the earliest stage in development at 

 which they can be recognized. At the present time no material is 

 available for this purpose, but I hope some may be obtained next 

 year. 



Breeding Experiments. 

 The original variegated plant, from which my variegated race has 

 been bred, appeared in the F., from a cross between the two normal 

 green races Ivy-leaf and Snowdrifts The F^ from this mating consisted 

 of normal green plants, two of which were selfed ; one of them gave a 

 large family, consisting of 160 plants, one of which was variegated. 

 The variegated plant was selfed and gave a family containing green, 

 variegated and yellow plants. Two of these variegated plants again 

 were selfed, and gave families containing the same three classes of 

 offspring. The foregoing results are set out in detail in Table I. 



TABLE I. 



Ivy-leaf x Snowdrift 



I 

 F, 45/09 



13 plants, all green 



451 



452 



59/10 

 129 plants, all green 



93/11 

 38 plants, all green 



I 



I 

 99/12 



GO/10 



159 green 1 variegated 



I I 



602 601 



92/11 



25 green ti variegated 7 yellow 



92' 92-' 92" 92''* 



I 

 I 



100/12 



48 gi-een 12 variegated 10 yellow 



993 



251 green 16 variegated 38 yellow 

 1003-8* 



1001 



100- « 



991 99- 



The plants were selfed but in each 

 case the inflorescence died 



* Used in crosses ; see Tables II and III. 



' For a description of these races see Journ. of Genetics, Vol. i. p. 102, 1911. 



