BIOTYPES AND HYBRIDS. 



13 



Fig. 2. — Bursa bursa-pastoris heteris. A typical specimen of my first pure cul- 

 ture of this biotype. 



Fig. 3. — Bursa bursa-pastoris heteris. Climax leaves of the rosette of a speci- 

 men growing in nature in Jackson Park, Chicago. 



