Variation occurring in Biscutella laevigata. 



19 



In one of the two individuals which had become smoother, 

 both surfaces of the leaves were now glabrous, but there were 

 numerous marginal hairs. In the other the change was much less 

 pronounced ; the under surface of the leaves was destitute of hairs 

 except along the midrib, but the upper surface was hairy except for 

 a very narrow strip bordering the midrib. 



Table IY. 



Detailed Analysis of the 36 Plants originally bearing Leaves with an 

 Intermediate Surface. 



Time of No. of 



sowing, plants. 



Aug. 4 

 Feb. 9 



No. of plants No. of 

 which had plants un- 

 varied, changed. 



March 21 



Totals 36 



8 



5 



4 



4 

 34 



Type of earlier leaves. Type of later leaves. 



Surface intermediate Surface intermediate. 

 „ „ smooth, hair3 on 



margins. 



„ „ Surface smooth, hairs on 



margins. 



,, „ Surface smooth, hairs on 



margins or lobes. 



„ Surface smooth, hairs on 



lobes. 



„ Surface smooth, hairs on 



lobes, or smooth. 



„ Quite smooth. 



„ „ Surface smooth, except 



for 1 — 2 hairs at the 

 leaf - teeth ; hairs on 

 margins. 



„ „ Surface smooth, hairs on 



margins. 



„ „ Surface smooth, hairs on 



margins or lobes. 



„ Surface smooth, hairs on 



lobes. 



„ „ Quite smooth. 



Thus of the thirty-six plants originally bearing leaves with an 

 intermediate surface only two remained unchanged. 



These thirty-six plants included the survivors (thirteen) of those 

 descendants of A and B which originally produced leaves with an 

 intermediate surface 

 Table Y. 



the variations occurring in them are shown in 



G 2 



