212 Inheritance in Ricinus communis, L. 



Of 4 families grown from mahogany F^ plants, 3 bred true (34 

 plants), while the other consisted of 15 mahogany and 3 rose and red- 

 blush. The parent of this family was self-fertilised, but it is possible 

 that accidental admixture of seed may have taken place. 



The back-cross jPi x mahogany. 



A single back cross was made and produced seeds giving rise to 37 

 rose and 43 mahogany (expectation 40 : 40). 



Gonclusion. 



Red-blush and mahogany are an allelomorphic pair of characters. 



2. The Gross Green x Mahogany. 



The ^i. Fourteen plants were grown. The stem colour was rose. 



The F^. Some difficulty was experienced in classifying the plants. 

 Green and mahogany could be distinguished easily, but there appeared 

 to be several shades of rose, grading down to red-blush. A new type 

 was recorded which was called " tinged." The young leaves are strongly 

 reddened, but the colour disappears as the leaves unfold, so that old 

 leaves are practically green. The glands on the leaf stalk retain their 

 colour, and a faint amount of colour is seen in the stem. 



In an F^ population some confusion is likely to arise in classifying 

 the plants, owing to the fact that it is not always easy to distinguish 

 between some of the paler types of red-blush and tinged. In practice 

 the various shades of rose and tinged were grouped together. Grouping 

 the plants into (a) rose and tinged, (6) mahogany, and (c) green the 

 following results were obtained : 



Totals 



Expectation on 10 



