IOWA ACADEMY OF SCIENCES. 213 



Epidermis. — The palisade-like epidermal cells with thickened 

 exterior walls, the latter much thinner; occasionally with thin 

 cross-walls so that the epidermal layer consists of two layers. 

 The cuticle of uniform thickness, the cuticularized layer 

 strongly developed, lighter in color than cellulose layers. 

 But all of the walls carry more or less pigment, with an abund- 

 ance of tannin. 



Nutrient layer. — This consists of two portions, the cells of 

 upper i^art larger and thinner than lower. In ripe seed very 

 much compressed, but can be made out readily by treating with 

 chloral hydrate. Cells contain pigment, tannin, and protein 

 grains, though the latter are not abundant. 



Osteosclcrid. — This consists of a single row of cells and does 

 not differ essentially from that of B. canad<-nsis. The cell- walls 

 are much lighter in color than the pigment layer, and with a 

 small cell cavity; in some cases the cells are not triangular in 

 shape, but I- shaped, as in many leguminous seeds. 



Pigment layer. — Cells elongated, thick walled, two or more 

 rows. The walls, colored dark brown, when treated with ferric 

 chloride show an abundance of tannin. 



Endosperm. — The bulk of the endosperm consists of thick- 

 walled cells which color blue with chloride of zinc, consisting 

 of cellulose. The lower part of endosperm consists of smaller 

 elongated cells. As stated by Hirsch, these cells collapse 

 readily, and not only serve to convey nutrient material to the 

 growing embryo, but to make room for its expansion. The 

 aleurone layer does not differ essentially from most of the cells 

 of endosperm, except that the cells are somewhat smaller. 

 Cells contain fat and protein grains. 



Embryo — The cells of first row with thick walls uniform in 

 size, those below larger and irregular in shape Cells contain 

 fat and protein cell-walls and starch. Tannin absent. 



BERBERIS VULGARIS L.^'~ 



Fruit and-'ieed characters. — Baccate fruit, born in a loose raceme, 

 scarlet, four to five lines long, two to three seeded; seeds light 

 brown, ovate, two to three sided, two to two and one-half lines 

 long; testa minutely roughened; h'lum and micropyle in lower 

 narrow end; the hilum forms a depressed round cavity with a 

 raised border. 



19 j Holfert. 26 

 ^^ ( Hirsch, 19. 



