48 BURSA BURSA-PASTORIS AND BURSA HEEGERI : 



059.89 : This typical specimen of Bursa heegeri was castrated and polli- 

 nated with pollen from a specimen of B. dp. simplex which differed from 

 the usual condition of that biotype in having the apex of the leaves taper- 

 ing: and acutish. This condition has been shown to be merely a fluctua- 

 tion (see p. 26), so that the plant used in this cross is to be considered a 



FIG. 23. Bursa bursa-pastoris simplex X heegeri, F t . Incomplete domi- 

 nance of the heteris characteristics produces a form resembling B. bp. 

 rhomboidea, but mostly with longer, sharper primary lobes. 



typical specimen of B. bp. simplex. The pollen-parent of this family was 

 a sib of the pistil-parent of the family last described, and the two speci- 

 mens of B. heegeri involved in these two families were likewise sibs, so 

 that these two crosses were essentially reciprocal. The seeds were sown 

 April 25, 1906, and produced 23 offspring, which were intermediate be- 

 tween B. bp. heteris and B. bp. rhomboidea as to the rosette characters, and 

 in which they were indistinguishable from the reciprocal hybrid family, 



