20 



BURSA BURSA-PASTORIS AND BURSA HEEGERI 



Fig. 11. Fig. 9. 



Fig. 10. 



Fig. 9. — Bursa bursa-pastoiis tenuis from my first pure culture of this biotype. 



Fig. 10. — Bursa bursa-pastoris tenuis from ;i hybrid progeny. 



Fig. 11. — Bursa bursa-pastoris tenuis. A stunted sib of plant shown in fig. 9. 



