Inheritance of the heptandra-iorm of Digitalis purpurea L. 267 



Fig. 7. All parts are clearly present, but the stamens are united into three 

 groups. Note the prominence of the posterior median lobe, e, of the accessory corolla. 



Fig. 8. All accessory organs are clearly present, the posterior accessory stamens 

 being represented by sessile, non-functional halfanthers. The ventral pair of normal 

 stamens, k, k, are united with the ventral accessory stamen, g. 



Fig. 9. One ventral lobe, i, of the accessory corolla is missing, presumably 

 remaining attached to the the ventral triple stamen formed by the union of the 

 ventral pair of normal stamens with the ventral accessory stamen. The dorsal pair 

 of normal stamens, 1, 1, are also" united with the lateral accessory stamens, h, h. The 

 dorsal accessory stamens, p, p, are more completely developed, but still non-functional. 



Plate XVI. 



Fig. 10. A raceme of normal Digitalis purpurea L. 



Fig. n. A raceme of the more common form of Digitalis purpurea heptandra 

 DE CHAMISSO. 



Fig. 12. Extreme heptandra-iorm shown by a plant grown in the Botanic Garden 

 of the Rijks-Universiteit, Groningen, Holland, in 1908. Photograph kindly supplied 

 by DR. TINE TAMMES. 



