Structure, etc., of Epiphegus Virginiana. 371 



for their feeble development. The whole area of wood is 

 very small, there being but two rows of cells present, some- 

 times three. These cells have thickened cell walls, stained 

 with safranin, and include spiral tracheae, annular and retic- 

 ulated tracheids. This extreme reduction in xylem tissue 

 is in accord with the colorless parasitic condition of the 

 plant, and agrees with Wilson's and with Smith's observa- 

 tions on Conopholis and Aphyllon. 



Within is the region of the internal phloem. This devel- 

 opment was not noted in Schrenk's description of the stem 

 bundles. It consists of but few cells, showing identically 

 the structure of the outer phloem, with its small and large 

 thin-walled cells. Rarely this area is as large as the outer 

 phloem area. It is absent from some bundles. Epiphegus 

 is therefore another plant that must be added to the rapidly 

 increasing list of those showing bicollateral stem bundles. 



Parenchyma cells lying next the bundles, both internal and 

 lateral to them, show a tendency to develop thickening in 

 their walls, and take on the safranin stain in the outer layers 

 just as do the cells of the hard bast. 



In sections made near the top of the stem, the general 

 appearance is much the same as in sections lower down, 

 except that the bundles are smaller and weaker-looking. 

 There is considerable reduction in the relative amount of 

 phloem here, though it is still much greater in amount than 

 the wood. The internal phloem is here much reduced or 

 may be quite absent. The triangular shape of the stem is 

 more marked here than lower down, and hairs are more 

 numerous. 



This entire stem structure has evidently been greatly mod- 

 ified by the parasitic habit of the plant. The phloem is exces- 

 sively developed, being the chief highway for the passage of 

 food. For elaborated sap is taken directly from the beech 

 and the phloem is the region fitted to convey such material, 

 The xylem shows great reduction, and seems almost useless 

 to the plant. For even the function of support has been 



