162 Trans. Acad. Sci. of St. Louis. 



30.8 /A long. Cuticle evenly developed; the wide light line 

 below the cuticle colors light blue with chlor-iodide of zinc ; 

 the cuticularized layer takes the same color ; the remainder of 

 the cell-wall below, a darker blue. The cell-cavity is wide at 

 the base but is abruptly contracted near the light line, and 

 contains pigment, tannin, and protein grains. 



Osteosclerid . Cells are small, wide in proportion to their 

 length, thick- walled, and color blue with chlor-iodide of zinc. 



Nutrient. This layer is much compressed. The cells are 

 thin-walled, elongated, and contain an abundance of brown 

 pigment and tannin. 



Endosperm. The thick-walled, nearly isodiametric aleu- 

 rone cells form a continuous layer ; the walls are stratified ; 

 large pore-canals connect with adjoining cells ; this layer is 

 followed by the reserve cellulose. The walls are differentiated 

 into three parts — primary, secondary, and tertiary. The 

 stratified tertiary membrane colors blue with chlor-iodide of 

 zinc, but not so deeply as the secondary stratified walls. The 

 internal part of the endosperm consists of thick-walled, elon- 

 gated cells with a small cavity. The cells of this part as well 

 as of the middle portion contain protein. 



Embryo. Cells of the first row, the epidermis, are smaller 

 than those below, nearly isodiametric, with thick exterior walls. 

 The interior cells are more loosely arranged. All of the cells 

 contain fat and protein. The superior face of the cotyledon 

 consists of several rows of palisade cells. Crystals of 

 oxalate of lime are common in the interior cells. 



ROBINIA, L. 



Testa variously colored. Endosperm present. Nutrient 

 layer compressed, containing pigment and tannin. The flowers 

 and presumably the ovules contain a glucoside, robinin. The 

 term has also been applied to the yellow coloring matter found 

 in other parts of the tree. 



RoBlNiA Pseud ACACIA, L. 



PI. XIV. f. 1-lf. 



This species has been studied by Nadelmann, Huss, and 

 Holfert; its germination by Lubbock and others. Testa and 



