The F,. 



213 



7— 7 Tinged _ _ _ 22 



13—10 „ — — 1* 11 



* Probable vicinist. 



From these results it will be seen that rose breeds true in 2 families 

 containing 88 plants, and segregates into rose, green, tinged, and 

 mahogany in 5 families. Remembering the difficulty of distinguishing 

 between rose and tinged, and classifying the plants into rose and tinged, 

 green and mahogany, we obtain the ratia 138 : 36 : 48, with expectation 

 139 : 41 : 41 on a 10:3:3 basis. Rose segregates into rose and mahogany 

 in 2 families, in the proportion of 39 rose : 10 mahogany (expectation 

 37 : 1 2 on a 3:1 basis). Rose segregates into rose and green in 3 

 families, in the proportion of 122 rose to 37 green (expectation 119:40 

 on a 3 : 1 basis). 



Two families from mahogany ^2 plants segregate into mahogany and 

 tinged in the ratio 83 : 34 (expectation 88 : 29 on a 3 : 1 basis). 



Four families from green F2, plants segregate into green and tinged, 

 99 : 28 (expectation 95 : 32 on a 3 : 1 basis). 



Two families from F^ plants breed true (33 plants). One family 

 contained a green plant, which is ascribed to vicinism. 



Back-crosses. 



Back-crosses were made of ^1 with green, and ^1 with mahogany. 

 The results are set forth below : 



15—2 



