BIOTYPES AND HYBRIDS. 



47 



(059.56) were sown November 1, 1906, and produced 24 plants, all agree- 

 ing" perfectly with the original type as described (fig. 22). These became 

 diseased later, however, and produced no seed. 



056.88 : This plant was considered a typical specimen of B. bp. simplex, 

 though a little more vigorous and broader-leafed than usual. It was care- 

 fully castrated and pollinated with pollen from a plant belonging" to my 

 first culture of B. heegeri (059). The seeds were sown April 25, 1906, and 



FIG. '22. Biirsa heegeri. Second controlled generation. 



produced 108 offspring', all resembling" B. heegeri more closely than B. bp. 

 simplex, but they differed markedly from the former because of the imper- 

 fect dominance of the hctcris characteristics . On this account these plants 

 had some of the characteristics of B. bp. rhomboidea and could be properly 

 described as intermediate between B. bp. rhomboidea and B. bp. heteris (fig". 

 23). A few of these died without seeding", but all that came to maturity 

 had the triangnlar capsules typical of Bursa bursa-pastoris . One family 

 was raised from unguarded seeds of one of these plants (0688.212), as 

 described below. 



