Pammel — Caryopsis and Endosperm of some Grasses. 201 



of the larger grains in Triticicm, Hordeum, and Bromus are 

 plainly stratified. Compound grains occur in Avena, Zizania, 

 Arundinaria and many other grasses. The embryo is joined 

 to the endosperm by its columnar epithelium. The cells of 

 the embryo are rich in albuminoids. In the region of the radicle 

 and caulicle a few simple round starch grains occur in Zea. 



Short descriptions follow of all the species here studied. As 

 to the synonymy and arrangement I have followed Gray's 

 Manual, 6th edition, for most of the American species. 

 Otherwise Kew Index and Lamson-Scribner, Grasses of Ten- 

 nessee. The material was obtained from the herbaria of the 

 Iowa State College of Agriculture and Mechanic Arts, and 

 the Missouri Botanical Garden. To Miss Charlotte M. King 

 I am indebted for the faithful execution of my drawings. 



ORYZEAE. 



The genus Oryza has been described and figured by numer- 

 ous investigators, Harz, 1 Tschirch & Oesterle, 2 Hanausek, 3 

 Moeller, 4 von Hohnel, 6 Tschirch, 6 Wiley 7 and other writers. 



Oryza sativa, L. As in several other grasses the protective 

 features are preserved in the glumes. Harz has studied these 

 as well as the testa and pericarp. The pericarp consists of the 

 epidermis and a compressed layer. The epidermal cells are 

 longer than the underlying rows of cells. The latter layer is 

 much compressed. The testa consists of one to two rows of 

 cells with somewhat thickened walls. The structure of the nu- 

 cellus can scarcely be made out. The nucellus is followed by 

 the aleurone layer which consists of one to two rows of thin- 

 walled cells. The endosperm makes up the bulk of the seed. 

 It is smooth and somewhat vitreous, and the cells are densely 

 filled with the separate components of the compound starch 



1 1. c. 1276. /. Ill (1,2,3,5). 2 Anatomischer Atlas. 9. pl.45. 



3 DieNahrungs- und Genussmittel aus dem Pflanzenreiche. Kassel. 45. 

 1884. 



4 Mikrospie der Nahrungs- und Genussmittel aus dem Pflanzenreiche. 

 Berlin. 109. /. 79-83. 1886. 



6 Haberlandt. Wiss-prakt. Unters. 1: 151. 



6 Angewandte Pflanzenanatomie. 85. /. 70. 



7 Foods and food adulterations, etc. Bull. U. S. Dept. Agrl Div. 

 Chem. 13: 1194. pi. 52. 



