Structure, etc., of Epiphegus Virginiana. 397 



7. Chasmogamic flowers are equally numerous on plants 

 growing in shade as in sunshine. A small percentage of 

 them produces good capsules ; not all are sterile, as indicated 

 in botanical works. 



8. The chasmogamic type of flower is the more primitive, 

 the cleistogamic has been evolved from it by gradual modi- 

 fication of all its parts. 



9. On the aerial parts stomata are abundant and wide- 

 spread. 



10. Bicollateral bundles are here frequent and well devel- 

 oped, while as in other parasites that have been described, 

 the xylem is relatively small, the phloem relatively large in 

 amount. 



11. Complicated and anastomosing bicollateral vascular 

 bundles occur likewise in the tuber. 



12. The so-called "grapplers" arise endogenously, and 

 are true roots, though by degeneration the root-cap has been 

 lost. In structure they show degenerate histological pecu- 

 liarities. 



13. Histologically it is shown that the cleistogamic flow- 

 ers are physiologically but not morphologically cleistogamic. 

 They retain a fairly well-developed nectary that probably 

 represents a fifth stamen. 



14. The microspore follows the type of development com- 

 mon to angiosperms, but the mature grain shows division 

 into two distinct nucleated protoplasmic masses. 



15. The macrospore develops normally, but the endo- 

 sperm nucleus produces a precocious endosperm, as in other 

 related parasities, that grows up round the egg cell. 



16. The developing embryo shows no trace of cotyledons. 



17. The parasitic relation is established from the beech- 

 root, rather than from Epiphegus, and is early shown as an 

 invading ramifying tissue composed of large richly proto- 

 plasmis cells and tracheids, that eventually establish a highly 

 complicated relation in the mature tuber of Epiphegus. 



