198 Trans. Acad. Sci, of St. Louis. 



chyma wanting. The third row of parenchyma cells of 

 the inferior face longer than broad. Procambial vessels 

 yellowish. 



Centrosema, Benth. (Bradbiiri/a, Raf. ) 



Testa smooth. Endosperm sparingly developed. Cotyle- 

 dons with thick-walled, stratified cells, the reserve cellulose. 

 Chalon found endosperm present. 



Centrosema virginianum, Benth. (B. virginiana, L., Kze.) 



PI. XIX. f. 3, 5. 



Testa 150 fi, towards the ends 250 jx or more thick. 



Malpighian. Cells nearly colorless, 56 fx long; cuticle an 

 even layer ; cuticularized layer inconspicuous ; light line just 

 below the latter ; several pores extending into the wall below 

 the light line. Cell-cavity large at the base, abruptly con 

 tracted near the light line, containing one or more chroma- 

 tophores in the cavity. The cell-cavity is smaller in the upper 

 third of the cells and large near the base. 



Osteosclerids. The thick-walled cells 14 /x long, toward 

 the hilum 60-65 /i long. 1-shaped cells with upper and lower 

 bars nearly equal. Intercellular spaces elongated. 



Nutrient, This layer is composed of from three to twelve 

 rows of thin- walled cells. Cells in the lower portion carry 

 much more pigment and tannin than the upper. 



Endosperm. The aleurone cells are continuous, followed 

 by one or two rows of mucilaginous endosperm. The internal 

 part of the endosperm consists of thick-walled elongated cells 

 with a narrow lumen. Cells contain protein. 



Emhryo. Cells of the first row continuous and isodiamet- 

 ric, with exterior walls thickened and stratified. Cells below 

 are larger, the stratified walls greatly thickened and provided 

 with pore-canals. Although the germination of this species 

 has not been studied, the thick-walled cells are without doubt 

 analogous to the reserve cellulose in the cotyledons of other 

 plants. The walls respond quickly to the test for cellulose, 

 and are easily soluble in sulphuric acid. The cells contain no 

 starch, but an abundance of fat and protein. Palisade cells 

 wanting. 



