Of Aphyllon Unifloruvi, Gray. 1 1 3 



is not uniformly present, and some of the cortical cells show 

 it also. I have found no trace of a symbiotic fungus in the 

 epidermis. 



Beneath the epidermis is the cortex, some ten or twelve 

 cells deep. These cells contain many small, rounded starch 

 grains, which are usually placed on the lower and inner sides 

 of the cell. Chatin states that the epidermis contains fine 

 granules, and the parenchyma large granules, "ni verts ni 

 amylaces," but Koch states that starch is invariably present in 

 the roots of Orobanche. Chatin may possibly have reference 

 to the oil-like globules mentioned above. 



Within the cortex is a reduced and degenerate bundle-sys- 

 tem. The bundle-sheath is quite absent in some roots, in 

 others it is represented in patches. The arrangement of wood 

 and bast varies considerably. It is most commonly diarch. 

 A modification of this is found, in which the wood projects 

 on one side of the bundle, so that the phloem of that side is 

 subdivided. A smaller proportion show a triarch arrange- 

 ment, while in some there seems to be an indiscriminate dis- 

 tribution of wood elements. The xylem consists of rather 

 short, pitted-reticulate elements, and though less in bulk than 

 the phloem, is better differentiated. The phloem is composed 

 of elongated elements, filled with highly granular contents, in 

 wliich nuclei frequently persist. Sieve-tubes seem to be 

 entirely absent. Protoplasmic connections between the cells 

 corresponding functionally in all probability to similar pro- 

 cesses in sieve-tubes were sometimes observed. 



Root-hairs arc either entirely absent, or are doubtfully rep- 

 resented by a few small, widely scattered, dermal papills. 

 Absorption must therefore be impossible for these roots. This 

 is in harmony with Koch's statement as to the total absence 

 of root- hairs in Orobanche spcciosa, 0. minor, 0. ramosa, 

 and 0. Hcdcrcv, which he studied embryologically. Koch 

 finds a root-cap on the soil-roots, /. c, the secondary 

 s 



