216 IOWA ACADEMY OF SCIENCES. 



the hilum forming a prominent pit with raised border. Micro- 

 scopically this seed does not differ essentially from B. vulgaris. 

 The epidermal cells frequently with a cell- wall across the mid- 

 dle. Cell-walls slightly stratified 



Nutrient layer. — Cells as in B. vulgaris. The osteosclerid 

 layer shows elongated, as well as triangular, intercellular 

 spaces. 



Parenclujma latter. — -Consists of a granular narrow zone of 

 small cells. The endosperm is divided into two parts; the 

 inner, of elongated cells; the first row of cells of embryo 

 smaller than those underneath. 



BERBERIS AQUIFOLIUM PursJl. 



Fruit and seed characters. — Fruit baccate, borne in rather 

 short racemes, ovate or ellipsoid, smooth, deep purple or blue, 

 with a glaucous bloom; usually four to six seeded; seed oblong- 

 obovoid, obtusely three-sided, two lines long. Testa pale brown 

 and somewhat shining; micropyle and hilum adjacent. The 

 latter forms a depression with a thick dar^ margin. The raphe 

 extending along the obtuse inner edge, chalaza at the apex. 



Epidermis— Cells very thick-walled, brown. Cuticle well 

 developed, slightly irregular. The second layer of cell-wall 

 not well developed, lighter in color than the third. This pro- 

 jects in the form of cones down between the thickened third 

 layer of cell -wall The third layer is very much thickened, 

 with small radiating canals, as well as very evident stratifica- 

 tion. The internal wall, or fourth layer, is very narrow. The 

 cell cavity is very much reduced; it reaches its greatest length 

 in the central portion of the cell. In some cases it has thinner 

 walls on lateral sides. The great thickening of the cell-wall, 

 evident stratification and small cell -cavity characterize this 

 species and others studied of the sub-genus Mahonia. 



Nutrient liyer. — This consists of several rows of cells, those 

 of the first layer elongated and much larger than the succeed- 

 ing. Decidedly irregular. The cells in lower portion elon- 

 gated, thinner- walled. Cells carry considerable pigment. 



Osteosclerid. — This layer does not differ essentially from those 

 previously described. It consists of a single row of cells with 

 greatly thickened walls, and a small cell cavity, and the char- 

 acteristic intercellular space. 



