396 Cooke and Schively on Observations on the 



young apex has been placed laterally, so as to give a true 

 apo-geotropic growth. As it elongates, it keeps on differ- 

 entiating in two distinct regions. The upper region develops 

 numerous bracts, in whose axils flower-rudiments appear. 

 In this region the bundles become steadily more regular and 

 definite in arrangement. It finally bcomes the aerial stem 

 of the mature plant. 



The lower part, with its irregular bundles and emerging 

 roots, becomes the tuber of the mature plant. The haus- 

 torial organ keeps growing in length mostly, pushing on 

 through the tissues of the parasite and ramifying in all 

 directions through the tuber. In the mature plant it is 

 confined to the lower region of the tuber. The divisions 

 and branchings of this organ keep increasing till finally 

 there is produced the complicated, almost unintelligible 

 structure of the mature haustorial connection of Epiphegus. 



Conclusions. 



1. Epiphegus Virginiana is a plant that illustrates in its 

 various structures degeneration due to parasitic habits. 



2. All evidence shows that it is parasitic only on roots of 

 the beech-tree, and that it is annual in duration. 



3. Seedling tubers appear in June, and steadily develop 

 till August-October. 



4. The vegetative part of the plant is the subterranean 

 or semisubterranean tuber, the aerial portion and at times 

 subterranean shoots from the tuber are reproductive. 



5. Two distinct floral types — that are connected by trans- 

 ition forms — are observed, viz., the chasmogamic and the 

 cleistogamic. Of these the cleistogamic is the commoner, 

 and may alone occur on many plants. 



6. Flowers of each type are confined to distinct areas of a 

 plant. Chasmogamic flowers do not extend to the termina- 

 tion of branches, but beyond them are cleistogamic ones. 

 (Gray, also Britten and Brown, leave it to be inferred that 

 chasmogamic flowers are in the uppermost part.) 



