220 IOWA ACADEMY OF SCIENCES. 



Osteosclerid. — The cells of this are thick- walled and have the 

 shape of an I, like the cells of- the second layer in the testa of 

 leguminous seeds. The narrow parts meet below, allowing- an 

 intercellular space between the projecting arms. These cells 

 are much smaller than those of Berberis. 



Pigment layer. — This consists of short, thick- walled cells 

 radially elongated, carrying more pigment than the cells of the 

 parencnyma layer. 



Parenchyma layer. — Not strongly developed and varies in 

 thickness in difier nt parts of the seed. The cells are elon- 

 gated, but somewhat irregular; contain protein grains. 



Endosperm. — This makes up the bulk of the seed, is a pure, 

 white, hard substance. Cell -walls greatly thickened, differen- 

 tiated into three well-defined portions. The cells contain fat 

 and protein grains, but no starch. The first layer of cells of 

 endosperm does not differ materially from the remainder. 

 There is, however, a slight difference in the cells of the endo- 

 sperm next to the embryo; these are smaller and radially 

 elongated. 



DIPHYLLEIA CYMOSA Michx. 



Fruit and seed characters — Baccate fruit blue, four to six 

 lines long, by four to five lines oblong or globose, usually two- 

 seeded. Seeds oblong, curved at the base, usually two-sided. 

 Testa reddish, wrinkled. Hilum with a white scar, in a some- 

 what depressed cavity, and a conspicuous tubercle towards the 

 dorsal side. 



Epidermis. — The epidermal cells are rather short, in some 

 cases elongated, and in others isodiametric. The cuticle well 

 developed, and as in Berberis the wall is differentiated into three 

 parts. The portion below the cuticle is thicker and lighter in 

 color. The middle portion of the wall is irregularly thickened, 

 producing cone-like projections between the lateral walls. The 

 internal wall is somewhat brownish and strongly stratified. 



Nutrient layer. — The cells of this layer are thinner-walled, 

 considerably elongated; the layer is variable in thickness, con- 

 sisting of three or four rows of cells. 



Osteosclerid. — This layer so characteristic in the Berberis^ does 

 not appear in this genus. 



Pigment ta?/er.— This is but slightly differentiated. 



Endosperm. — Well developed, differentiated into two parts. 

 The first row of cells, aleurone, next to the testa, does not 



