IOWA ACADEMY OF SCIENCES. 217 



Pigment layer — Several rows of much compressed, thick- 

 walled, elongated cells of darker color than the nutrient layer. 



Parenchyma layer. — Much compressed cells with granular 

 contents of protein grains, somewhat variable in thickness. 



Endosperm. — This constitutes the bulk- of the seed; the first 

 row of cells does not differ essentially from those beneath, 

 except that they are somewhat smaller. In the lower portion 

 of endosperm, the cells are smaller, elongated, and thinner- 

 walled. The thick walls of the endosperm cells are differen- 

 tiated into three parts, the inner being much more strongly 

 developed. On the addition of sulphuric acid and iodine, the 

 walls color blue The cells do not contain starch, but protein 

 grains and fat. 



Embryo. — Does not differ from other species studied. 



BERBERIS REPENS Lincll. 



Baccate fruit in a comparatively short raceme, blue with a 

 glaucous bloom, four to five lines long, five or more seeded. 

 Seeds dark brown, ovate, elliptical or quadrangular, curved at 

 base, two lines long, two or more sided, obtuse or somewhat 

 angular; dorsal side convex. Testa minutely roughened, 

 prominent raphe on one side, chalaza at the tip. Micropyle 

 and hilum adjacent, hilar pit small with a well marked border. 



Epidermis. — This species does not differ from the preceding. 

 The cuticle is well developed. The remainder of cell-wall 

 enormously thickened; the third layer of wall shows prominent 

 stratification; the cell-cavity is much reduced, the walls colored 

 brown. 



Nutrient layer. — This layer seems to be suppressed in some 

 places. The cells are not so regular as in other species. In 

 some cases they are more elongated, in others are the character- 

 istic triangular intercellular spaces; the cell-cavity in this spe- 

 cies is larger than in other species of the sub-genus. The epi- 

 dermal cells are much longer, and as regards stratification, it has 

 reached its highest development in this species. It would not 

 be difficult to separate this species from the other members of 

 this sub-genus by the characters here presented. 



Pigment layer. — Cells narrow, elongated, thick-walled, brown. 

 An abundance of tannin. 



Parenchyma layer. — A much compressed layer. Cells carry- 

 ing a large amount of granular matter, consisting -mostly of 

 protein grains. 



