164 Trans. Acad. Sci. of St. Louis. 



sperm limited to one or two rows of cells. Nutrient layer 

 with a great deal of pigment. 



Malpighian. Cells quite uniform, 166 /i long. Cuticle 

 irregular, followed by a narrow cuticularized layer, which 

 refracts light strongly; the wide light line follows the cu- 

 ticularized portion ; the pore-canals extend beyond the line. 

 When the cells are cut at right angles or obliquely the pores 

 appear disconnected, with small projections ; the projections 

 between the pores color blue with chlor-iodide of zinc. The 

 cell- cavity is wide at the base, tapering upward. Each cell 

 usually contains a round chromatophore; occasionally it is 

 elliptical or nearly square. With chlor-iodide of zinc the 

 walls, light line, and cuticularized layer color blue. Some of 

 the cells contain a brown or violet pigment. Tannin and 

 some protein also occur. 



Osteosclerid. Cells small when compared with the Mal- 

 pighian, 20.4 /A long. The upper and lower bar nearly equal. 



CeU-cavity rather large and containing protein, some pigment, 



and tannin. 



Nutrient. This layer is differentiated into two parts: (1) 



a narrow layer consisting of two to four rows of elongated 



cells containing some pigment, (2) three or four rows of 



much larger, thin-walled cells. 



Mycotic. In this layer the cells are elongated, thick-walled, 



and somewhat irregular, comprising ten to fourteen rows; 



also some pigment. 



Nucellus. Consists of one or two rows of thick-walled 



cells. 



Endosperm. This consists of a narrow continuous layer of 



one or two rows of cells — the aleurone, whose walls are 



thickened. The cells contain protein grains. 



Embryo. Cells of the first row smaller than those below, 



forming a continuous row ; the exterior walls thickened ; cells 



below are more loosely arranged, thinner-walled, a pore-canal 



present, and a triangular intercellular space at their angles. 



Palisade parenchyma wanting. The cells, except the first 



row, contain an abundance of large starch grains. Protein 



grains and fat in all of the cells. 



